Methods moved to interface, vendors updated (#40)

* Move to interfaces

* update vendor

Co-authored-by: Artem Piskun <artem.piskun@myoffice.team>
This commit is contained in:
Artem Piskun 2020-06-01 10:08:11 +03:00 committed by GitHub
parent aa374638bf
commit 0191d5c84e
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35 changed files with 4085 additions and 91 deletions

1
.gitignore vendored Normal file
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@ -0,0 +1 @@
examples/

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@ -20,7 +20,7 @@ The lib is under MIT but be sure you are familiar with [Discogs API Terms of Use
Install Install
-------- --------
go get -u github.com/irlndts/go-discogs go get github.com/irlndts/go-discogs
Usage Usage
--------- ---------
@ -31,7 +31,7 @@ import "github.com/irlndts/go-discogs"
``` ```
Some requests require authentification (as any user). According to [Discogs](https://www.discogs.com/developers/#page:authentication,header:authentication-discogs-auth-flow), to send requests with Discogs Auth, you have two options: sending your credentials in the query string with key and secret parameters or a [token parameter](https://www.discogs.com/settings/developers). Some requests require authentification (as any user). According to [Discogs](https://www.discogs.com/developers/#page:authentication,header:authentication-discogs-auth-flow), to send requests with Discogs Auth, you have two options: sending your credentials in the query string with key and secret parameters or a [token parameter](https://www.discogs.com/settings/developers).
This is token way example:
```go ```go
client, err := discogs.New(&discogs.Options{ client, err := discogs.New(&discogs.Options{
UserAgent: "Some Name", UserAgent: "Some Name",
@ -43,7 +43,7 @@ client, err := discogs.New(&discogs.Options{
#### Releases #### Releases
```go ```go
release, _ := client.Database.Release(9893847) release, _ := client.Release(9893847)
fmt.Println(release.Artists[0].Name, " - ", release.Title) fmt.Println(release.Artists[0].Name, " - ", release.Title)
// St. Petersburg Ska-Jazz Review - Elephant Riddim // St. Petersburg Ska-Jazz Review - Elephant Riddim
``` ```
@ -82,7 +82,7 @@ type SearchRequest struct {
Example Example
```go ```go
request := discogs.SearchRequest{Artist: "reggaenauts", ReleaseTitle: "river rock", Page: 0, PerPage: 1} request := discogs.SearchRequest{Artist: "reggaenauts", ReleaseTitle: "river rock", Page: 0, PerPage: 1}
search, _ := client.Search.Search(request) search, _ := client.Search(request)
for _, r := range search.Results { for _, r := range search.Results {
fmt.Println(r.Title) fmt.Println(r.Title)

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@ -12,20 +12,39 @@ const (
mastersURI = "/masters/" mastersURI = "/masters/"
) )
// DatabaseService ... // DatabaseService is an interface to work with database.
type DatabaseService struct { type DatabaseService interface {
// Artist represents a person in the discogs database.
Artist(artistID int) (*Artist, error)
// ArtistReleases returns a list of releases and masters associated with the artist.
ArtistReleases(artistID int, pagination *Pagination) (*ArtistReleases, error)
// Label returns a label.
Label(labelID int) (*Label, error)
// LabelReleases returns a list of Releases associated with the label.
LabelReleases(labelID int, pagination *Pagination) (*LabelReleases, error)
// Master returns a master release.
Master(masterID int) (*Master, error)
// MasterVersions retrieves a list of all Releases that are versions of this master.
MasterVersions(masterID int, pagination *Pagination) (*MasterVersions, error)
// Release returns release by release's ID.
Release(releaseID int) (*Release, error)
// ReleaseRating retruns community release rating.
ReleaseRating(releaseID int) (*ReleaseRating, error)
}
type databaseService struct {
url string url string
currency string currency string
} }
func newDatabaseService(url string, currency string) *DatabaseService { func newDatabaseService(url string, currency string) DatabaseService {
return &DatabaseService{ return &databaseService{
url: url, url: url,
currency: currency, currency: currency,
} }
} }
// Release serves relesase response from discogs // Release serves relesase response from discogs.
type Release struct { type Release struct {
Title string `json:"title"` Title string `json:"title"`
ID int `json:"id"` ID int `json:"id"`
@ -63,8 +82,7 @@ type Release struct {
Year int `json:"year"` Year int `json:"year"`
} }
// Release returns release by release's ID func (s *databaseService) Release(releaseID int) (*Release, error) {
func (s *DatabaseService) Release(releaseID int) (*Release, error) {
params := url.Values{} params := url.Values{}
params.Set("curr_abbr", s.currency) params.Set("curr_abbr", s.currency)
@ -73,14 +91,13 @@ func (s *DatabaseService) Release(releaseID int) (*Release, error) {
return release, err return release, err
} }
// ReleaseRating serves response for community release rating request // ReleaseRating serves response for community release rating request.
type ReleaseRating struct { type ReleaseRating struct {
ID int `json:"release_id"` ID int `json:"release_id"`
Rating Rating `json:"rating"` Rating Rating `json:"rating"`
} }
// ReleaseRating retruns community release rating func (s *databaseService) ReleaseRating(releaseID int) (*ReleaseRating, error) {
func (s *DatabaseService) ReleaseRating(releaseID int) (*ReleaseRating, error) {
var rating *ReleaseRating var rating *ReleaseRating
err := request(s.url+releasesURI+strconv.Itoa(releaseID)+"/rating", nil, &rating) err := request(s.url+releasesURI+strconv.Itoa(releaseID)+"/rating", nil, &rating)
return rating, err return rating, err
@ -105,8 +122,7 @@ type Artist struct {
DataQuality string `json:"data_quality"` DataQuality string `json:"data_quality"`
} }
// Artist represents a person in the discogs database func (s *databaseService) Artist(artistID int) (*Artist, error) {
func (s *DatabaseService) Artist(artistID int) (*Artist, error) {
var artist *Artist var artist *Artist
err := request(s.url+artistsURI+strconv.Itoa(artistID), nil, &artist) err := request(s.url+artistsURI+strconv.Itoa(artistID), nil, &artist)
return artist, err return artist, err
@ -118,8 +134,7 @@ type ArtistReleases struct {
Releases []ReleaseSource `json:"releases"` Releases []ReleaseSource `json:"releases"`
} }
// ArtistReleases returns a list of releases and masters associated with the artist. func (s *databaseService) ArtistReleases(artistID int, pagination *Pagination) (*ArtistReleases, error) {
func (s *DatabaseService) ArtistReleases(artistID int, pagination *Pagination) (*ArtistReleases, error) {
var releases *ArtistReleases var releases *ArtistReleases
err := request(s.url+artistsURI+strconv.Itoa(artistID)+"/releases", pagination.params(), &releases) err := request(s.url+artistsURI+strconv.Itoa(artistID)+"/releases", pagination.params(), &releases)
return releases, err return releases, err
@ -141,8 +156,7 @@ type Label struct {
DataQuality string `json:"data_quality"` DataQuality string `json:"data_quality"`
} }
// Label returns a label. func (s *databaseService) Label(labelID int) (*Label, error) {
func (s *DatabaseService) Label(labelID int) (*Label, error) {
var label *Label var label *Label
err := request(s.url+labelsURI+strconv.Itoa(labelID), nil, &label) err := request(s.url+labelsURI+strconv.Itoa(labelID), nil, &label)
return label, err return label, err
@ -154,8 +168,7 @@ type LabelReleases struct {
Releases []ReleaseSource `json:"releases"` Releases []ReleaseSource `json:"releases"`
} }
// LabelReleases returns a list of Releases associated with the label. func (s *databaseService) LabelReleases(labelID int, pagination *Pagination) (*LabelReleases, error) {
func (s *DatabaseService) LabelReleases(labelID int, pagination *Pagination) (*LabelReleases, error) {
var releases *LabelReleases var releases *LabelReleases
err := request(s.url+labelsURI+strconv.Itoa(labelID)+"/releases", pagination.params(), &releases) err := request(s.url+labelsURI+strconv.Itoa(labelID)+"/releases", pagination.params(), &releases)
return releases, err return releases, err
@ -187,8 +200,7 @@ type Master struct {
DataQuality string `json:"data_quality"` DataQuality string `json:"data_quality"`
} }
// Master returns a master release func (s *databaseService) Master(masterID int) (*Master, error) {
func (s *DatabaseService) Master(masterID int) (*Master, error) {
var master *Master var master *Master
err := request(s.url+mastersURI+strconv.Itoa(masterID), nil, &master) err := request(s.url+mastersURI+strconv.Itoa(masterID), nil, &master)
return master, err return master, err
@ -200,8 +212,7 @@ type MasterVersions struct {
Versions []Version `json:"versions"` Versions []Version `json:"versions"`
} }
// MasterVersions retrieves a list of all Releases that are versions of this master func (s *databaseService) MasterVersions(masterID int, pagination *Pagination) (*MasterVersions, error) {
func (s *DatabaseService) MasterVersions(masterID int, pagination *Pagination) (*MasterVersions, error) {
var versions *MasterVersions var versions *MasterVersions
err := request(s.url+mastersURI+strconv.Itoa(masterID)+"/versions", pagination.params(), &versions) err := request(s.url+mastersURI+strconv.Itoa(masterID)+"/versions", pagination.params(), &versions)
return versions, err return versions, err

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@ -60,7 +60,7 @@ func TestDatabaseServiceRelease(t *testing.T) {
defer ts.Close() defer ts.Close()
d := initDiscogsClient(t, &Options{URL: ts.URL}) d := initDiscogsClient(t, &Options{URL: ts.URL})
release, err := d.Database.Release(8138518) release, err := d.Release(8138518)
if err != nil { if err != nil {
t.Fatalf("failed to get release: %s", err) t.Fatalf("failed to get release: %s", err)
} }
@ -78,7 +78,7 @@ func TestDatabaseServiceMaster(t *testing.T) {
defer ts.Close() defer ts.Close()
d := initDiscogsClient(t, &Options{URL: ts.URL}) d := initDiscogsClient(t, &Options{URL: ts.URL})
master, err := d.Database.Master(718441) master, err := d.Master(718441)
if err != nil { if err != nil {
t.Fatalf("failed to get master: %s", err) t.Fatalf("failed to get master: %s", err)
} }
@ -95,7 +95,7 @@ func TestDatabaseServiceArtist(t *testing.T) {
defer ts.Close() defer ts.Close()
d := initDiscogsClient(t, &Options{URL: ts.URL}) d := initDiscogsClient(t, &Options{URL: ts.URL})
artist, err := d.Database.Artist(38661) artist, err := d.Artist(38661)
if err != nil { if err != nil {
t.Fatalf("failed to get master: %s", err) t.Fatalf("failed to get master: %s", err)
} }

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@ -24,16 +24,21 @@ type Options struct {
Token string Token string
} }
// Discogs is a Discogs' client for making Discogs API requests. // Discogs is an interface for making Discogs API requests.
type Discogs struct { type Discogs interface {
Database *DatabaseService DatabaseService
Search *SearchService SearchService
}
type discogs struct {
DatabaseService
SearchService
} }
var header *http.Header var header *http.Header
// New returns a new discogs API client. // New returns a new discogs API client.
func New(o *Options) (*Discogs, error) { func New(o *Options) (Discogs, error) {
header = &http.Header{} header = &http.Header{}
if o == nil || o.UserAgent == "" { if o == nil || o.UserAgent == "" {
@ -56,9 +61,9 @@ func New(o *Options) (*Discogs, error) {
o.URL = discogsAPI o.URL = discogsAPI
} }
return &Discogs{ return discogs{
Database: newDatabaseService(o.URL, cur), newDatabaseService(o.URL, cur),
Search: newSearchService(o.URL + "/database/search"), newSearchService(o.URL + "/database/search"),
}, nil }, nil
} }

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@ -5,11 +5,11 @@ import (
) )
const ( const (
testUserAgent = "UnitTestClient/0.0.2 +https://github.com/irlndts/go-discogs" testUserAgent = "UnitTestClient/0.0.2"
testToken = "" testToken = ""
) )
func initDiscogsClient(t *testing.T, options *Options) *Discogs { func initDiscogsClient(t *testing.T, options *Options) Discogs {
if options == nil { if options == nil {
options = &Options{ options = &Options{
UserAgent: testUserAgent, UserAgent: testUserAgent,
@ -66,19 +66,19 @@ func TestCurrency(t *testing.T) {
want string want string
err error err error
}{ }{
{currency: "", want: "USD", err: nil}, {currency: "", want: "USD"},
{currency: "USD", want: "USD", err: nil}, {currency: "USD", want: "USD"},
{currency: "GBP", want: "GBP", err: nil}, {currency: "GBP", want: "GBP"},
{currency: "EUR", want: "EUR", err: nil}, {currency: "EUR", want: "EUR"},
{currency: "CAD", want: "CAD", err: nil}, {currency: "CAD", want: "CAD"},
{currency: "AUD", want: "AUD", err: nil}, {currency: "AUD", want: "AUD"},
{currency: "JPY", want: "JPY", err: nil}, {currency: "JPY", want: "JPY"},
{currency: "CHF", want: "CHF", err: nil}, {currency: "CHF", want: "CHF"},
{currency: "MXN", want: "MXN", err: nil}, {currency: "MXN", want: "MXN"},
{currency: "BRL", want: "BRL", err: nil}, {currency: "BRL", want: "BRL"},
{currency: "NZD", want: "NZD", err: nil}, {currency: "NZD", want: "NZD"},
{currency: "SEK", want: "SEK", err: nil}, {currency: "SEK", want: "SEK"},
{currency: "ZAR", want: "ZAR", err: nil}, {currency: "ZAR", want: "ZAR"},
{currency: "RUR", want: "", err: ErrCurrencyNotSupported}, {currency: "RUR", want: "", err: ErrCurrencyNotSupported},
} }
for i, tt := range tests { for i, tt := range tests {

21
doc.go Normal file
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@ -0,0 +1,21 @@
/*
Package discogs is a Go client library for the Discogs API.
The discogs package provides a client for accessing the Discogs API.
First of all import library and init client variable.
According to discogs api documentation you must provide your user-agent.
Some requests require authentification (as any user).
According to Discogs, to send requests with Discogs Auth, you have two options:
sending your credentials in the query string with key and secret parameters or
a token parameter. This is token way example:
client, err := discogs.New(&discogs.Options{
UserAgent: "Some Name",
Currency: "EUR", // optional, "USD" (default), "GBP", "EUR", "CAD", "AUD", "JPY", "CHF", "MXN", "BRL", "NZD", "SEK", "ZAR" are allowed
Token: "Some Token", // optional
URL: "https://api.discogs.com", // optional
})
*/
package discogs

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@ -1,26 +0,0 @@
package main
import (
"fmt"
"github.com/irlndts/go-discogs"
)
func main() {
d, err := discogs.New(&discogs.Options{
UserAgent: "TestDiscogsClient/0.0.1 +http://example.com",
Currency: "USD",
Token: "",
})
if err != nil {
fmt.Println(err)
return
}
master, err := d.Database.Master(718441)
if err != nil {
fmt.Println(err)
return
}
fmt.Printf("%+v\n", master)
}

2
go.mod
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@ -2,4 +2,4 @@ module github.com/irlndts/go-discogs
go 1.14 go 1.14
require github.com/google/go-cmp v0.4.0 require github.com/google/go-cmp v0.4.1

4
go.sum
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@ -1,4 +1,4 @@
github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4= github.com/google/go-cmp v0.4.1 h1:/exdXoGamhu5ONeUJH0deniYLWYvQwW66yvlfiiKTu0=
github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE= github.com/google/go-cmp v0.4.1/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4= golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0= golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

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@ -5,13 +5,22 @@ import (
"strconv" "strconv"
) )
// SearchService ... // SearchService is an interface to work with search.
type SearchService struct { type SearchService interface {
// Search makes search request to discogs.
// Issue a search query to database. This endpoint accepts pagination parameters.
// Authentication (as any user) is required.
// https://www.discogs.com/developers/#page:database,header:database-search
Search(req SearchRequest) (*Search, error)
}
// searchService ...
type searchService struct {
url string url string
} }
func newSearchService(url string) *SearchService { func newSearchService(url string) SearchService {
return &SearchService{ return &searchService{
url: url, url: url,
} }
} }
@ -136,11 +145,7 @@ type Result struct {
MasterID int `json:"master_id,omitempty"` MasterID int `json:"master_id,omitempty"`
} }
// Search makes search request to discogs. func (s *searchService) Search(req SearchRequest) (*Search, error) {
// Issue a search query to our database. This endpoint accepts pagination parameters.
// Authentication (as any user) is required.
// https://www.discogs.com/developers/#page:database,header:database-search
func (s *SearchService) Search(req SearchRequest) (*Search, error) {
var search *Search var search *Search
err := request(s.url, req.params(), &search) err := request(s.url, req.params(), &search)
return search, err return search, err

27
vendor/github.com/google/go-cmp/LICENSE generated vendored Normal file
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@ -0,0 +1,27 @@
Copyright (c) 2017 The Go Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

659
vendor/github.com/google/go-cmp/cmp/compare.go generated vendored Normal file
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@ -0,0 +1,659 @@
// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
// Package cmp determines equality of values.
//
// This package is intended to be a more powerful and safer alternative to
// reflect.DeepEqual for comparing whether two values are semantically equal.
// It is intended to only be used in tests, as performance is not a goal and
// it may panic if it cannot compare the values. Its propensity towards
// panicking means that its unsuitable for production environments where a
// spurious panic may be fatal.
//
// The primary features of cmp are:
//
// • When the default behavior of equality does not suit the needs of the test,
// custom equality functions can override the equality operation.
// For example, an equality function may report floats as equal so long as they
// are within some tolerance of each other.
//
// • Types that have an Equal method may use that method to determine equality.
// This allows package authors to determine the equality operation for the types
// that they define.
//
// • If no custom equality functions are used and no Equal method is defined,
// equality is determined by recursively comparing the primitive kinds on both
// values, much like reflect.DeepEqual. Unlike reflect.DeepEqual, unexported
// fields are not compared by default; they result in panics unless suppressed
// by using an Ignore option (see cmpopts.IgnoreUnexported) or explicitly
// compared using the Exporter option.
package cmp
import (
"fmt"
"reflect"
"strings"
"github.com/google/go-cmp/cmp/internal/diff"
"github.com/google/go-cmp/cmp/internal/flags"
"github.com/google/go-cmp/cmp/internal/function"
"github.com/google/go-cmp/cmp/internal/value"
)
// Equal reports whether x and y are equal by recursively applying the
// following rules in the given order to x and y and all of their sub-values:
//
// • Let S be the set of all Ignore, Transformer, and Comparer options that
// remain after applying all path filters, value filters, and type filters.
// If at least one Ignore exists in S, then the comparison is ignored.
// If the number of Transformer and Comparer options in S is greater than one,
// then Equal panics because it is ambiguous which option to use.
// If S contains a single Transformer, then use that to transform the current
// values and recursively call Equal on the output values.
// If S contains a single Comparer, then use that to compare the current values.
// Otherwise, evaluation proceeds to the next rule.
//
// • If the values have an Equal method of the form "(T) Equal(T) bool" or
// "(T) Equal(I) bool" where T is assignable to I, then use the result of
// x.Equal(y) even if x or y is nil. Otherwise, no such method exists and
// evaluation proceeds to the next rule.
//
// • Lastly, try to compare x and y based on their basic kinds.
// Simple kinds like booleans, integers, floats, complex numbers, strings, and
// channels are compared using the equivalent of the == operator in Go.
// Functions are only equal if they are both nil, otherwise they are unequal.
//
// Structs are equal if recursively calling Equal on all fields report equal.
// If a struct contains unexported fields, Equal panics unless an Ignore option
// (e.g., cmpopts.IgnoreUnexported) ignores that field or the Exporter option
// explicitly permits comparing the unexported field.
//
// Slices are equal if they are both nil or both non-nil, where recursively
// calling Equal on all non-ignored slice or array elements report equal.
// Empty non-nil slices and nil slices are not equal; to equate empty slices,
// consider using cmpopts.EquateEmpty.
//
// Maps are equal if they are both nil or both non-nil, where recursively
// calling Equal on all non-ignored map entries report equal.
// Map keys are equal according to the == operator.
// To use custom comparisons for map keys, consider using cmpopts.SortMaps.
// Empty non-nil maps and nil maps are not equal; to equate empty maps,
// consider using cmpopts.EquateEmpty.
//
// Pointers and interfaces are equal if they are both nil or both non-nil,
// where they have the same underlying concrete type and recursively
// calling Equal on the underlying values reports equal.
//
// Before recursing into a pointer, slice element, or map, the current path
// is checked to detect whether the address has already been visited.
// If there is a cycle, then the pointed at values are considered equal
// only if both addresses were previously visited in the same path step.
func Equal(x, y interface{}, opts ...Option) bool {
vx := reflect.ValueOf(x)
vy := reflect.ValueOf(y)
// If the inputs are different types, auto-wrap them in an empty interface
// so that they have the same parent type.
var t reflect.Type
if !vx.IsValid() || !vy.IsValid() || vx.Type() != vy.Type() {
t = reflect.TypeOf((*interface{})(nil)).Elem()
if vx.IsValid() {
vvx := reflect.New(t).Elem()
vvx.Set(vx)
vx = vvx
}
if vy.IsValid() {
vvy := reflect.New(t).Elem()
vvy.Set(vy)
vy = vvy
}
} else {
t = vx.Type()
}
s := newState(opts)
s.compareAny(&pathStep{t, vx, vy})
return s.result.Equal()
}
// Diff returns a human-readable report of the differences between two values.
// It returns an empty string if and only if Equal returns true for the same
// input values and options.
//
// The output is displayed as a literal in pseudo-Go syntax.
// At the start of each line, a "-" prefix indicates an element removed from x,
// a "+" prefix to indicates an element added to y, and the lack of a prefix
// indicates an element common to both x and y. If possible, the output
// uses fmt.Stringer.String or error.Error methods to produce more humanly
// readable outputs. In such cases, the string is prefixed with either an
// 's' or 'e' character, respectively, to indicate that the method was called.
//
// Do not depend on this output being stable. If you need the ability to
// programmatically interpret the difference, consider using a custom Reporter.
func Diff(x, y interface{}, opts ...Option) string {
r := new(defaultReporter)
eq := Equal(x, y, Options(opts), Reporter(r))
d := r.String()
if (d == "") != eq {
panic("inconsistent difference and equality results")
}
return d
}
type state struct {
// These fields represent the "comparison state".
// Calling statelessCompare must not result in observable changes to these.
result diff.Result // The current result of comparison
curPath Path // The current path in the value tree
curPtrs pointerPath // The current set of visited pointers
reporters []reporter // Optional reporters
// recChecker checks for infinite cycles applying the same set of
// transformers upon the output of itself.
recChecker recChecker
// dynChecker triggers pseudo-random checks for option correctness.
// It is safe for statelessCompare to mutate this value.
dynChecker dynChecker
// These fields, once set by processOption, will not change.
exporters []exporter // List of exporters for structs with unexported fields
opts Options // List of all fundamental and filter options
}
func newState(opts []Option) *state {
// Always ensure a validator option exists to validate the inputs.
s := &state{opts: Options{validator{}}}
s.curPtrs.Init()
s.processOption(Options(opts))
return s
}
func (s *state) processOption(opt Option) {
switch opt := opt.(type) {
case nil:
case Options:
for _, o := range opt {
s.processOption(o)
}
case coreOption:
type filtered interface {
isFiltered() bool
}
if fopt, ok := opt.(filtered); ok && !fopt.isFiltered() {
panic(fmt.Sprintf("cannot use an unfiltered option: %v", opt))
}
s.opts = append(s.opts, opt)
case exporter:
s.exporters = append(s.exporters, opt)
case reporter:
s.reporters = append(s.reporters, opt)
default:
panic(fmt.Sprintf("unknown option %T", opt))
}
}
// statelessCompare compares two values and returns the result.
// This function is stateless in that it does not alter the current result,
// or output to any registered reporters.
func (s *state) statelessCompare(step PathStep) diff.Result {
// We do not save and restore curPath and curPtrs because all of the
// compareX methods should properly push and pop from them.
// It is an implementation bug if the contents of the paths differ from
// when calling this function to when returning from it.
oldResult, oldReporters := s.result, s.reporters
s.result = diff.Result{} // Reset result
s.reporters = nil // Remove reporters to avoid spurious printouts
s.compareAny(step)
res := s.result
s.result, s.reporters = oldResult, oldReporters
return res
}
func (s *state) compareAny(step PathStep) {
// Update the path stack.
s.curPath.push(step)
defer s.curPath.pop()
for _, r := range s.reporters {
r.PushStep(step)
defer r.PopStep()
}
s.recChecker.Check(s.curPath)
// Cycle-detection for slice elements (see NOTE in compareSlice).
t := step.Type()
vx, vy := step.Values()
if si, ok := step.(SliceIndex); ok && si.isSlice && vx.IsValid() && vy.IsValid() {
px, py := vx.Addr(), vy.Addr()
if eq, visited := s.curPtrs.Push(px, py); visited {
s.report(eq, reportByCycle)
return
}
defer s.curPtrs.Pop(px, py)
}
// Rule 1: Check whether an option applies on this node in the value tree.
if s.tryOptions(t, vx, vy) {
return
}
// Rule 2: Check whether the type has a valid Equal method.
if s.tryMethod(t, vx, vy) {
return
}
// Rule 3: Compare based on the underlying kind.
switch t.Kind() {
case reflect.Bool:
s.report(vx.Bool() == vy.Bool(), 0)
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
s.report(vx.Int() == vy.Int(), 0)
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
s.report(vx.Uint() == vy.Uint(), 0)
case reflect.Float32, reflect.Float64:
s.report(vx.Float() == vy.Float(), 0)
case reflect.Complex64, reflect.Complex128:
s.report(vx.Complex() == vy.Complex(), 0)
case reflect.String:
s.report(vx.String() == vy.String(), 0)
case reflect.Chan, reflect.UnsafePointer:
s.report(vx.Pointer() == vy.Pointer(), 0)
case reflect.Func:
s.report(vx.IsNil() && vy.IsNil(), 0)
case reflect.Struct:
s.compareStruct(t, vx, vy)
case reflect.Slice, reflect.Array:
s.compareSlice(t, vx, vy)
case reflect.Map:
s.compareMap(t, vx, vy)
case reflect.Ptr:
s.comparePtr(t, vx, vy)
case reflect.Interface:
s.compareInterface(t, vx, vy)
default:
panic(fmt.Sprintf("%v kind not handled", t.Kind()))
}
}
func (s *state) tryOptions(t reflect.Type, vx, vy reflect.Value) bool {
// Evaluate all filters and apply the remaining options.
if opt := s.opts.filter(s, t, vx, vy); opt != nil {
opt.apply(s, vx, vy)
return true
}
return false
}
func (s *state) tryMethod(t reflect.Type, vx, vy reflect.Value) bool {
// Check if this type even has an Equal method.
m, ok := t.MethodByName("Equal")
if !ok || !function.IsType(m.Type, function.EqualAssignable) {
return false
}
eq := s.callTTBFunc(m.Func, vx, vy)
s.report(eq, reportByMethod)
return true
}
func (s *state) callTRFunc(f, v reflect.Value, step Transform) reflect.Value {
v = sanitizeValue(v, f.Type().In(0))
if !s.dynChecker.Next() {
return f.Call([]reflect.Value{v})[0]
}
// Run the function twice and ensure that we get the same results back.
// We run in goroutines so that the race detector (if enabled) can detect
// unsafe mutations to the input.
c := make(chan reflect.Value)
go detectRaces(c, f, v)
got := <-c
want := f.Call([]reflect.Value{v})[0]
if step.vx, step.vy = got, want; !s.statelessCompare(step).Equal() {
// To avoid false-positives with non-reflexive equality operations,
// we sanity check whether a value is equal to itself.
if step.vx, step.vy = want, want; !s.statelessCompare(step).Equal() {
return want
}
panic(fmt.Sprintf("non-deterministic function detected: %s", function.NameOf(f)))
}
return want
}
func (s *state) callTTBFunc(f, x, y reflect.Value) bool {
x = sanitizeValue(x, f.Type().In(0))
y = sanitizeValue(y, f.Type().In(1))
if !s.dynChecker.Next() {
return f.Call([]reflect.Value{x, y})[0].Bool()
}
// Swapping the input arguments is sufficient to check that
// f is symmetric and deterministic.
// We run in goroutines so that the race detector (if enabled) can detect
// unsafe mutations to the input.
c := make(chan reflect.Value)
go detectRaces(c, f, y, x)
got := <-c
want := f.Call([]reflect.Value{x, y})[0].Bool()
if !got.IsValid() || got.Bool() != want {
panic(fmt.Sprintf("non-deterministic or non-symmetric function detected: %s", function.NameOf(f)))
}
return want
}
func detectRaces(c chan<- reflect.Value, f reflect.Value, vs ...reflect.Value) {
var ret reflect.Value
defer func() {
recover() // Ignore panics, let the other call to f panic instead
c <- ret
}()
ret = f.Call(vs)[0]
}
// sanitizeValue converts nil interfaces of type T to those of type R,
// assuming that T is assignable to R.
// Otherwise, it returns the input value as is.
func sanitizeValue(v reflect.Value, t reflect.Type) reflect.Value {
// TODO(dsnet): Workaround for reflect bug (https://golang.org/issue/22143).
if !flags.AtLeastGo110 {
if v.Kind() == reflect.Interface && v.IsNil() && v.Type() != t {
return reflect.New(t).Elem()
}
}
return v
}
func (s *state) compareStruct(t reflect.Type, vx, vy reflect.Value) {
var vax, vay reflect.Value // Addressable versions of vx and vy
var mayForce, mayForceInit bool
step := StructField{&structField{}}
for i := 0; i < t.NumField(); i++ {
step.typ = t.Field(i).Type
step.vx = vx.Field(i)
step.vy = vy.Field(i)
step.name = t.Field(i).Name
step.idx = i
step.unexported = !isExported(step.name)
if step.unexported {
if step.name == "_" {
continue
}
// Defer checking of unexported fields until later to give an
// Ignore a chance to ignore the field.
if !vax.IsValid() || !vay.IsValid() {
// For retrieveUnexportedField to work, the parent struct must
// be addressable. Create a new copy of the values if
// necessary to make them addressable.
vax = makeAddressable(vx)
vay = makeAddressable(vy)
}
if !mayForceInit {
for _, xf := range s.exporters {
mayForce = mayForce || xf(t)
}
mayForceInit = true
}
step.mayForce = mayForce
step.pvx = vax
step.pvy = vay
step.field = t.Field(i)
}
s.compareAny(step)
}
}
func (s *state) compareSlice(t reflect.Type, vx, vy reflect.Value) {
isSlice := t.Kind() == reflect.Slice
if isSlice && (vx.IsNil() || vy.IsNil()) {
s.report(vx.IsNil() && vy.IsNil(), 0)
return
}
// NOTE: It is incorrect to call curPtrs.Push on the slice header pointer
// since slices represents a list of pointers, rather than a single pointer.
// The pointer checking logic must be handled on a per-element basis
// in compareAny.
//
// A slice header (see reflect.SliceHeader) in Go is a tuple of a starting
// pointer P, a length N, and a capacity C. Supposing each slice element has
// a memory size of M, then the slice is equivalent to the list of pointers:
// [P+i*M for i in range(N)]
//
// For example, v[:0] and v[:1] are slices with the same starting pointer,
// but they are clearly different values. Using the slice pointer alone
// violates the assumption that equal pointers implies equal values.
step := SliceIndex{&sliceIndex{pathStep: pathStep{typ: t.Elem()}, isSlice: isSlice}}
withIndexes := func(ix, iy int) SliceIndex {
if ix >= 0 {
step.vx, step.xkey = vx.Index(ix), ix
} else {
step.vx, step.xkey = reflect.Value{}, -1
}
if iy >= 0 {
step.vy, step.ykey = vy.Index(iy), iy
} else {
step.vy, step.ykey = reflect.Value{}, -1
}
return step
}
// Ignore options are able to ignore missing elements in a slice.
// However, detecting these reliably requires an optimal differencing
// algorithm, for which diff.Difference is not.
//
// Instead, we first iterate through both slices to detect which elements
// would be ignored if standing alone. The index of non-discarded elements
// are stored in a separate slice, which diffing is then performed on.
var indexesX, indexesY []int
var ignoredX, ignoredY []bool
for ix := 0; ix < vx.Len(); ix++ {
ignored := s.statelessCompare(withIndexes(ix, -1)).NumDiff == 0
if !ignored {
indexesX = append(indexesX, ix)
}
ignoredX = append(ignoredX, ignored)
}
for iy := 0; iy < vy.Len(); iy++ {
ignored := s.statelessCompare(withIndexes(-1, iy)).NumDiff == 0
if !ignored {
indexesY = append(indexesY, iy)
}
ignoredY = append(ignoredY, ignored)
}
// Compute an edit-script for slices vx and vy (excluding ignored elements).
edits := diff.Difference(len(indexesX), len(indexesY), func(ix, iy int) diff.Result {
return s.statelessCompare(withIndexes(indexesX[ix], indexesY[iy]))
})
// Replay the ignore-scripts and the edit-script.
var ix, iy int
for ix < vx.Len() || iy < vy.Len() {
var e diff.EditType
switch {
case ix < len(ignoredX) && ignoredX[ix]:
e = diff.UniqueX
case iy < len(ignoredY) && ignoredY[iy]:
e = diff.UniqueY
default:
e, edits = edits[0], edits[1:]
}
switch e {
case diff.UniqueX:
s.compareAny(withIndexes(ix, -1))
ix++
case diff.UniqueY:
s.compareAny(withIndexes(-1, iy))
iy++
default:
s.compareAny(withIndexes(ix, iy))
ix++
iy++
}
}
}
func (s *state) compareMap(t reflect.Type, vx, vy reflect.Value) {
if vx.IsNil() || vy.IsNil() {
s.report(vx.IsNil() && vy.IsNil(), 0)
return
}
// Cycle-detection for maps.
if eq, visited := s.curPtrs.Push(vx, vy); visited {
s.report(eq, reportByCycle)
return
}
defer s.curPtrs.Pop(vx, vy)
// We combine and sort the two map keys so that we can perform the
// comparisons in a deterministic order.
step := MapIndex{&mapIndex{pathStep: pathStep{typ: t.Elem()}}}
for _, k := range value.SortKeys(append(vx.MapKeys(), vy.MapKeys()...)) {
step.vx = vx.MapIndex(k)
step.vy = vy.MapIndex(k)
step.key = k
if !step.vx.IsValid() && !step.vy.IsValid() {
// It is possible for both vx and vy to be invalid if the
// key contained a NaN value in it.
//
// Even with the ability to retrieve NaN keys in Go 1.12,
// there still isn't a sensible way to compare the values since
// a NaN key may map to multiple unordered values.
// The most reasonable way to compare NaNs would be to compare the
// set of values. However, this is impossible to do efficiently
// since set equality is provably an O(n^2) operation given only
// an Equal function. If we had a Less function or Hash function,
// this could be done in O(n*log(n)) or O(n), respectively.
//
// Rather than adding complex logic to deal with NaNs, make it
// the user's responsibility to compare such obscure maps.
const help = "consider providing a Comparer to compare the map"
panic(fmt.Sprintf("%#v has map key with NaNs\n%s", s.curPath, help))
}
s.compareAny(step)
}
}
func (s *state) comparePtr(t reflect.Type, vx, vy reflect.Value) {
if vx.IsNil() || vy.IsNil() {
s.report(vx.IsNil() && vy.IsNil(), 0)
return
}
// Cycle-detection for pointers.
if eq, visited := s.curPtrs.Push(vx, vy); visited {
s.report(eq, reportByCycle)
return
}
defer s.curPtrs.Pop(vx, vy)
vx, vy = vx.Elem(), vy.Elem()
s.compareAny(Indirect{&indirect{pathStep{t.Elem(), vx, vy}}})
}
func (s *state) compareInterface(t reflect.Type, vx, vy reflect.Value) {
if vx.IsNil() || vy.IsNil() {
s.report(vx.IsNil() && vy.IsNil(), 0)
return
}
vx, vy = vx.Elem(), vy.Elem()
if vx.Type() != vy.Type() {
s.report(false, 0)
return
}
s.compareAny(TypeAssertion{&typeAssertion{pathStep{vx.Type(), vx, vy}}})
}
func (s *state) report(eq bool, rf resultFlags) {
if rf&reportByIgnore == 0 {
if eq {
s.result.NumSame++
rf |= reportEqual
} else {
s.result.NumDiff++
rf |= reportUnequal
}
}
for _, r := range s.reporters {
r.Report(Result{flags: rf})
}
}
// recChecker tracks the state needed to periodically perform checks that
// user provided transformers are not stuck in an infinitely recursive cycle.
type recChecker struct{ next int }
// Check scans the Path for any recursive transformers and panics when any
// recursive transformers are detected. Note that the presence of a
// recursive Transformer does not necessarily imply an infinite cycle.
// As such, this check only activates after some minimal number of path steps.
func (rc *recChecker) Check(p Path) {
const minLen = 1 << 16
if rc.next == 0 {
rc.next = minLen
}
if len(p) < rc.next {
return
}
rc.next <<= 1
// Check whether the same transformer has appeared at least twice.
var ss []string
m := map[Option]int{}
for _, ps := range p {
if t, ok := ps.(Transform); ok {
t := t.Option()
if m[t] == 1 { // Transformer was used exactly once before
tf := t.(*transformer).fnc.Type()
ss = append(ss, fmt.Sprintf("%v: %v => %v", t, tf.In(0), tf.Out(0)))
}
m[t]++
}
}
if len(ss) > 0 {
const warning = "recursive set of Transformers detected"
const help = "consider using cmpopts.AcyclicTransformer"
set := strings.Join(ss, "\n\t")
panic(fmt.Sprintf("%s:\n\t%s\n%s", warning, set, help))
}
}
// dynChecker tracks the state needed to periodically perform checks that
// user provided functions are symmetric and deterministic.
// The zero value is safe for immediate use.
type dynChecker struct{ curr, next int }
// Next increments the state and reports whether a check should be performed.
//
// Checks occur every Nth function call, where N is a triangular number:
// 0 1 3 6 10 15 21 28 36 45 55 66 78 91 105 120 136 153 171 190 ...
// See https://en.wikipedia.org/wiki/Triangular_number
//
// This sequence ensures that the cost of checks drops significantly as
// the number of functions calls grows larger.
func (dc *dynChecker) Next() bool {
ok := dc.curr == dc.next
if ok {
dc.curr = 0
dc.next++
}
dc.curr++
return ok
}
// makeAddressable returns a value that is always addressable.
// It returns the input verbatim if it is already addressable,
// otherwise it creates a new value and returns an addressable copy.
func makeAddressable(v reflect.Value) reflect.Value {
if v.CanAddr() {
return v
}
vc := reflect.New(v.Type()).Elem()
vc.Set(v)
return vc
}

15
vendor/github.com/google/go-cmp/cmp/export_panic.go generated vendored Normal file
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@ -0,0 +1,15 @@
// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
// +build purego
package cmp
import "reflect"
const supportExporters = false
func retrieveUnexportedField(reflect.Value, reflect.StructField) reflect.Value {
panic("no support for forcibly accessing unexported fields")
}

25
vendor/github.com/google/go-cmp/cmp/export_unsafe.go generated vendored Normal file
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@ -0,0 +1,25 @@
// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
// +build !purego
package cmp
import (
"reflect"
"unsafe"
)
const supportExporters = true
// retrieveUnexportedField uses unsafe to forcibly retrieve any field from
// a struct such that the value has read-write permissions.
//
// The parent struct, v, must be addressable, while f must be a StructField
// describing the field to retrieve.
func retrieveUnexportedField(v reflect.Value, f reflect.StructField) reflect.Value {
// See https://github.com/google/go-cmp/issues/167 for discussion of the
// following expression.
return reflect.NewAt(f.Type, unsafe.Pointer(uintptr(unsafe.Pointer(v.UnsafeAddr()))+f.Offset)).Elem()
}

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// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
// +build !cmp_debug
package diff
var debug debugger
type debugger struct{}
func (debugger) Begin(_, _ int, f EqualFunc, _, _ *EditScript) EqualFunc {
return f
}
func (debugger) Update() {}
func (debugger) Finish() {}

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// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
// +build cmp_debug
package diff
import (
"fmt"
"strings"
"sync"
"time"
)
// The algorithm can be seen running in real-time by enabling debugging:
// go test -tags=cmp_debug -v
//
// Example output:
// === RUN TestDifference/#34
// ┌───────────────────────────────┐
// │ \ · · · · · · · · · · · · · · │
// │ · # · · · · · · · · · · · · · │
// │ · \ · · · · · · · · · · · · · │
// │ · · \ · · · · · · · · · · · · │
// │ · · · X # · · · · · · · · · · │
// │ · · · # \ · · · · · · · · · · │
// │ · · · · · # # · · · · · · · · │
// │ · · · · · # \ · · · · · · · · │
// │ · · · · · · · \ · · · · · · · │
// │ · · · · · · · · \ · · · · · · │
// │ · · · · · · · · · \ · · · · · │
// │ · · · · · · · · · · \ · · # · │
// │ · · · · · · · · · · · \ # # · │
// │ · · · · · · · · · · · # # # · │
// │ · · · · · · · · · · # # # # · │
// │ · · · · · · · · · # # # # # · │
// │ · · · · · · · · · · · · · · \ │
// └───────────────────────────────┘
// [.Y..M.XY......YXYXY.|]
//
// The grid represents the edit-graph where the horizontal axis represents
// list X and the vertical axis represents list Y. The start of the two lists
// is the top-left, while the ends are the bottom-right. The '·' represents
// an unexplored node in the graph. The '\' indicates that the two symbols
// from list X and Y are equal. The 'X' indicates that two symbols are similar
// (but not exactly equal) to each other. The '#' indicates that the two symbols
// are different (and not similar). The algorithm traverses this graph trying to
// make the paths starting in the top-left and the bottom-right connect.
//
// The series of '.', 'X', 'Y', and 'M' characters at the bottom represents
// the currently established path from the forward and reverse searches,
// separated by a '|' character.
const (
updateDelay = 100 * time.Millisecond
finishDelay = 500 * time.Millisecond
ansiTerminal = true // ANSI escape codes used to move terminal cursor
)
var debug debugger
type debugger struct {
sync.Mutex
p1, p2 EditScript
fwdPath, revPath *EditScript
grid []byte
lines int
}
func (dbg *debugger) Begin(nx, ny int, f EqualFunc, p1, p2 *EditScript) EqualFunc {
dbg.Lock()
dbg.fwdPath, dbg.revPath = p1, p2
top := "┌─" + strings.Repeat("──", nx) + "┐\n"
row := "│ " + strings.Repeat("· ", nx) + "│\n"
btm := "└─" + strings.Repeat("──", nx) + "┘\n"
dbg.grid = []byte(top + strings.Repeat(row, ny) + btm)
dbg.lines = strings.Count(dbg.String(), "\n")
fmt.Print(dbg)
// Wrap the EqualFunc so that we can intercept each result.
return func(ix, iy int) (r Result) {
cell := dbg.grid[len(top)+iy*len(row):][len("│ ")+len("· ")*ix:][:len("·")]
for i := range cell {
cell[i] = 0 // Zero out the multiple bytes of UTF-8 middle-dot
}
switch r = f(ix, iy); {
case r.Equal():
cell[0] = '\\'
case r.Similar():
cell[0] = 'X'
default:
cell[0] = '#'
}
return
}
}
func (dbg *debugger) Update() {
dbg.print(updateDelay)
}
func (dbg *debugger) Finish() {
dbg.print(finishDelay)
dbg.Unlock()
}
func (dbg *debugger) String() string {
dbg.p1, dbg.p2 = *dbg.fwdPath, dbg.p2[:0]
for i := len(*dbg.revPath) - 1; i >= 0; i-- {
dbg.p2 = append(dbg.p2, (*dbg.revPath)[i])
}
return fmt.Sprintf("%s[%v|%v]\n\n", dbg.grid, dbg.p1, dbg.p2)
}
func (dbg *debugger) print(d time.Duration) {
if ansiTerminal {
fmt.Printf("\x1b[%dA", dbg.lines) // Reset terminal cursor
}
fmt.Print(dbg)
time.Sleep(d)
}

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@ -0,0 +1,372 @@
// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
// Package diff implements an algorithm for producing edit-scripts.
// The edit-script is a sequence of operations needed to transform one list
// of symbols into another (or vice-versa). The edits allowed are insertions,
// deletions, and modifications. The summation of all edits is called the
// Levenshtein distance as this problem is well-known in computer science.
//
// This package prioritizes performance over accuracy. That is, the run time
// is more important than obtaining a minimal Levenshtein distance.
package diff
// EditType represents a single operation within an edit-script.
type EditType uint8
const (
// Identity indicates that a symbol pair is identical in both list X and Y.
Identity EditType = iota
// UniqueX indicates that a symbol only exists in X and not Y.
UniqueX
// UniqueY indicates that a symbol only exists in Y and not X.
UniqueY
// Modified indicates that a symbol pair is a modification of each other.
Modified
)
// EditScript represents the series of differences between two lists.
type EditScript []EditType
// String returns a human-readable string representing the edit-script where
// Identity, UniqueX, UniqueY, and Modified are represented by the
// '.', 'X', 'Y', and 'M' characters, respectively.
func (es EditScript) String() string {
b := make([]byte, len(es))
for i, e := range es {
switch e {
case Identity:
b[i] = '.'
case UniqueX:
b[i] = 'X'
case UniqueY:
b[i] = 'Y'
case Modified:
b[i] = 'M'
default:
panic("invalid edit-type")
}
}
return string(b)
}
// stats returns a histogram of the number of each type of edit operation.
func (es EditScript) stats() (s struct{ NI, NX, NY, NM int }) {
for _, e := range es {
switch e {
case Identity:
s.NI++
case UniqueX:
s.NX++
case UniqueY:
s.NY++
case Modified:
s.NM++
default:
panic("invalid edit-type")
}
}
return
}
// Dist is the Levenshtein distance and is guaranteed to be 0 if and only if
// lists X and Y are equal.
func (es EditScript) Dist() int { return len(es) - es.stats().NI }
// LenX is the length of the X list.
func (es EditScript) LenX() int { return len(es) - es.stats().NY }
// LenY is the length of the Y list.
func (es EditScript) LenY() int { return len(es) - es.stats().NX }
// EqualFunc reports whether the symbols at indexes ix and iy are equal.
// When called by Difference, the index is guaranteed to be within nx and ny.
type EqualFunc func(ix int, iy int) Result
// Result is the result of comparison.
// NumSame is the number of sub-elements that are equal.
// NumDiff is the number of sub-elements that are not equal.
type Result struct{ NumSame, NumDiff int }
// BoolResult returns a Result that is either Equal or not Equal.
func BoolResult(b bool) Result {
if b {
return Result{NumSame: 1} // Equal, Similar
} else {
return Result{NumDiff: 2} // Not Equal, not Similar
}
}
// Equal indicates whether the symbols are equal. Two symbols are equal
// if and only if NumDiff == 0. If Equal, then they are also Similar.
func (r Result) Equal() bool { return r.NumDiff == 0 }
// Similar indicates whether two symbols are similar and may be represented
// by using the Modified type. As a special case, we consider binary comparisons
// (i.e., those that return Result{1, 0} or Result{0, 1}) to be similar.
//
// The exact ratio of NumSame to NumDiff to determine similarity may change.
func (r Result) Similar() bool {
// Use NumSame+1 to offset NumSame so that binary comparisons are similar.
return r.NumSame+1 >= r.NumDiff
}
// Difference reports whether two lists of lengths nx and ny are equal
// given the definition of equality provided as f.
//
// This function returns an edit-script, which is a sequence of operations
// needed to convert one list into the other. The following invariants for
// the edit-script are maintained:
// • eq == (es.Dist()==0)
// • nx == es.LenX()
// • ny == es.LenY()
//
// This algorithm is not guaranteed to be an optimal solution (i.e., one that
// produces an edit-script with a minimal Levenshtein distance). This algorithm
// favors performance over optimality. The exact output is not guaranteed to
// be stable and may change over time.
func Difference(nx, ny int, f EqualFunc) (es EditScript) {
// This algorithm is based on traversing what is known as an "edit-graph".
// See Figure 1 from "An O(ND) Difference Algorithm and Its Variations"
// by Eugene W. Myers. Since D can be as large as N itself, this is
// effectively O(N^2). Unlike the algorithm from that paper, we are not
// interested in the optimal path, but at least some "decent" path.
//
// For example, let X and Y be lists of symbols:
// X = [A B C A B B A]
// Y = [C B A B A C]
//
// The edit-graph can be drawn as the following:
// A B C A B B A
// ┌─────────────┐
// C │_|_|\|_|_|_|_│ 0
// B │_|\|_|_|\|\|_│ 1
// A │\|_|_|\|_|_|\│ 2
// B │_|\|_|_|\|\|_│ 3
// A │\|_|_|\|_|_|\│ 4
// C │ | |\| | | | │ 5
// └─────────────┘ 6
// 0 1 2 3 4 5 6 7
//
// List X is written along the horizontal axis, while list Y is written
// along the vertical axis. At any point on this grid, if the symbol in
// list X matches the corresponding symbol in list Y, then a '\' is drawn.
// The goal of any minimal edit-script algorithm is to find a path from the
// top-left corner to the bottom-right corner, while traveling through the
// fewest horizontal or vertical edges.
// A horizontal edge is equivalent to inserting a symbol from list X.
// A vertical edge is equivalent to inserting a symbol from list Y.
// A diagonal edge is equivalent to a matching symbol between both X and Y.
// Invariants:
// • 0 ≤ fwdPath.X ≤ (fwdFrontier.X, revFrontier.X) ≤ revPath.X ≤ nx
// • 0 ≤ fwdPath.Y ≤ (fwdFrontier.Y, revFrontier.Y) ≤ revPath.Y ≤ ny
//
// In general:
// • fwdFrontier.X < revFrontier.X
// • fwdFrontier.Y < revFrontier.Y
// Unless, it is time for the algorithm to terminate.
fwdPath := path{+1, point{0, 0}, make(EditScript, 0, (nx+ny)/2)}
revPath := path{-1, point{nx, ny}, make(EditScript, 0)}
fwdFrontier := fwdPath.point // Forward search frontier
revFrontier := revPath.point // Reverse search frontier
// Search budget bounds the cost of searching for better paths.
// The longest sequence of non-matching symbols that can be tolerated is
// approximately the square-root of the search budget.
searchBudget := 4 * (nx + ny) // O(n)
// The algorithm below is a greedy, meet-in-the-middle algorithm for
// computing sub-optimal edit-scripts between two lists.
//
// The algorithm is approximately as follows:
// • Searching for differences switches back-and-forth between
// a search that starts at the beginning (the top-left corner), and
// a search that starts at the end (the bottom-right corner). The goal of
// the search is connect with the search from the opposite corner.
// • As we search, we build a path in a greedy manner, where the first
// match seen is added to the path (this is sub-optimal, but provides a
// decent result in practice). When matches are found, we try the next pair
// of symbols in the lists and follow all matches as far as possible.
// • When searching for matches, we search along a diagonal going through
// through the "frontier" point. If no matches are found, we advance the
// frontier towards the opposite corner.
// • This algorithm terminates when either the X coordinates or the
// Y coordinates of the forward and reverse frontier points ever intersect.
//
// This algorithm is correct even if searching only in the forward direction
// or in the reverse direction. We do both because it is commonly observed
// that two lists commonly differ because elements were added to the front
// or end of the other list.
//
// Running the tests with the "cmp_debug" build tag prints a visualization
// of the algorithm running in real-time. This is educational for
// understanding how the algorithm works. See debug_enable.go.
f = debug.Begin(nx, ny, f, &fwdPath.es, &revPath.es)
for {
// Forward search from the beginning.
if fwdFrontier.X >= revFrontier.X || fwdFrontier.Y >= revFrontier.Y || searchBudget == 0 {
break
}
for stop1, stop2, i := false, false, 0; !(stop1 && stop2) && searchBudget > 0; i++ {
// Search in a diagonal pattern for a match.
z := zigzag(i)
p := point{fwdFrontier.X + z, fwdFrontier.Y - z}
switch {
case p.X >= revPath.X || p.Y < fwdPath.Y:
stop1 = true // Hit top-right corner
case p.Y >= revPath.Y || p.X < fwdPath.X:
stop2 = true // Hit bottom-left corner
case f(p.X, p.Y).Equal():
// Match found, so connect the path to this point.
fwdPath.connect(p, f)
fwdPath.append(Identity)
// Follow sequence of matches as far as possible.
for fwdPath.X < revPath.X && fwdPath.Y < revPath.Y {
if !f(fwdPath.X, fwdPath.Y).Equal() {
break
}
fwdPath.append(Identity)
}
fwdFrontier = fwdPath.point
stop1, stop2 = true, true
default:
searchBudget-- // Match not found
}
debug.Update()
}
// Advance the frontier towards reverse point.
if revPath.X-fwdFrontier.X >= revPath.Y-fwdFrontier.Y {
fwdFrontier.X++
} else {
fwdFrontier.Y++
}
// Reverse search from the end.
if fwdFrontier.X >= revFrontier.X || fwdFrontier.Y >= revFrontier.Y || searchBudget == 0 {
break
}
for stop1, stop2, i := false, false, 0; !(stop1 && stop2) && searchBudget > 0; i++ {
// Search in a diagonal pattern for a match.
z := zigzag(i)
p := point{revFrontier.X - z, revFrontier.Y + z}
switch {
case fwdPath.X >= p.X || revPath.Y < p.Y:
stop1 = true // Hit bottom-left corner
case fwdPath.Y >= p.Y || revPath.X < p.X:
stop2 = true // Hit top-right corner
case f(p.X-1, p.Y-1).Equal():
// Match found, so connect the path to this point.
revPath.connect(p, f)
revPath.append(Identity)
// Follow sequence of matches as far as possible.
for fwdPath.X < revPath.X && fwdPath.Y < revPath.Y {
if !f(revPath.X-1, revPath.Y-1).Equal() {
break
}
revPath.append(Identity)
}
revFrontier = revPath.point
stop1, stop2 = true, true
default:
searchBudget-- // Match not found
}
debug.Update()
}
// Advance the frontier towards forward point.
if revFrontier.X-fwdPath.X >= revFrontier.Y-fwdPath.Y {
revFrontier.X--
} else {
revFrontier.Y--
}
}
// Join the forward and reverse paths and then append the reverse path.
fwdPath.connect(revPath.point, f)
for i := len(revPath.es) - 1; i >= 0; i-- {
t := revPath.es[i]
revPath.es = revPath.es[:i]
fwdPath.append(t)
}
debug.Finish()
return fwdPath.es
}
type path struct {
dir int // +1 if forward, -1 if reverse
point // Leading point of the EditScript path
es EditScript
}
// connect appends any necessary Identity, Modified, UniqueX, or UniqueY types
// to the edit-script to connect p.point to dst.
func (p *path) connect(dst point, f EqualFunc) {
if p.dir > 0 {
// Connect in forward direction.
for dst.X > p.X && dst.Y > p.Y {
switch r := f(p.X, p.Y); {
case r.Equal():
p.append(Identity)
case r.Similar():
p.append(Modified)
case dst.X-p.X >= dst.Y-p.Y:
p.append(UniqueX)
default:
p.append(UniqueY)
}
}
for dst.X > p.X {
p.append(UniqueX)
}
for dst.Y > p.Y {
p.append(UniqueY)
}
} else {
// Connect in reverse direction.
for p.X > dst.X && p.Y > dst.Y {
switch r := f(p.X-1, p.Y-1); {
case r.Equal():
p.append(Identity)
case r.Similar():
p.append(Modified)
case p.Y-dst.Y >= p.X-dst.X:
p.append(UniqueY)
default:
p.append(UniqueX)
}
}
for p.X > dst.X {
p.append(UniqueX)
}
for p.Y > dst.Y {
p.append(UniqueY)
}
}
}
func (p *path) append(t EditType) {
p.es = append(p.es, t)
switch t {
case Identity, Modified:
p.add(p.dir, p.dir)
case UniqueX:
p.add(p.dir, 0)
case UniqueY:
p.add(0, p.dir)
}
debug.Update()
}
type point struct{ X, Y int }
func (p *point) add(dx, dy int) { p.X += dx; p.Y += dy }
// zigzag maps a consecutive sequence of integers to a zig-zag sequence.
// [0 1 2 3 4 5 ...] => [0 -1 +1 -2 +2 ...]
func zigzag(x int) int {
if x&1 != 0 {
x = ^x
}
return x >> 1
}

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// Copyright 2019, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
package flags
// Deterministic controls whether the output of Diff should be deterministic.
// This is only used for testing.
var Deterministic bool

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// Copyright 2019, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
// +build !go1.10
package flags
// AtLeastGo110 reports whether the Go toolchain is at least Go 1.10.
const AtLeastGo110 = false

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// Copyright 2019, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
// +build go1.10
package flags
// AtLeastGo110 reports whether the Go toolchain is at least Go 1.10.
const AtLeastGo110 = true

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// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
// Package function provides functionality for identifying function types.
package function
import (
"reflect"
"regexp"
"runtime"
"strings"
)
type funcType int
const (
_ funcType = iota
tbFunc // func(T) bool
ttbFunc // func(T, T) bool
trbFunc // func(T, R) bool
tibFunc // func(T, I) bool
trFunc // func(T) R
Equal = ttbFunc // func(T, T) bool
EqualAssignable = tibFunc // func(T, I) bool; encapsulates func(T, T) bool
Transformer = trFunc // func(T) R
ValueFilter = ttbFunc // func(T, T) bool
Less = ttbFunc // func(T, T) bool
ValuePredicate = tbFunc // func(T) bool
KeyValuePredicate = trbFunc // func(T, R) bool
)
var boolType = reflect.TypeOf(true)
// IsType reports whether the reflect.Type is of the specified function type.
func IsType(t reflect.Type, ft funcType) bool {
if t == nil || t.Kind() != reflect.Func || t.IsVariadic() {
return false
}
ni, no := t.NumIn(), t.NumOut()
switch ft {
case tbFunc: // func(T) bool
if ni == 1 && no == 1 && t.Out(0) == boolType {
return true
}
case ttbFunc: // func(T, T) bool
if ni == 2 && no == 1 && t.In(0) == t.In(1) && t.Out(0) == boolType {
return true
}
case trbFunc: // func(T, R) bool
if ni == 2 && no == 1 && t.Out(0) == boolType {
return true
}
case tibFunc: // func(T, I) bool
if ni == 2 && no == 1 && t.In(0).AssignableTo(t.In(1)) && t.Out(0) == boolType {
return true
}
case trFunc: // func(T) R
if ni == 1 && no == 1 {
return true
}
}
return false
}
var lastIdentRx = regexp.MustCompile(`[_\p{L}][_\p{L}\p{N}]*$`)
// NameOf returns the name of the function value.
func NameOf(v reflect.Value) string {
fnc := runtime.FuncForPC(v.Pointer())
if fnc == nil {
return "<unknown>"
}
fullName := fnc.Name() // e.g., "long/path/name/mypkg.(*MyType).(long/path/name/mypkg.myMethod)-fm"
// Method closures have a "-fm" suffix.
fullName = strings.TrimSuffix(fullName, "-fm")
var name string
for len(fullName) > 0 {
inParen := strings.HasSuffix(fullName, ")")
fullName = strings.TrimSuffix(fullName, ")")
s := lastIdentRx.FindString(fullName)
if s == "" {
break
}
name = s + "." + name
fullName = strings.TrimSuffix(fullName, s)
if i := strings.LastIndexByte(fullName, '('); inParen && i >= 0 {
fullName = fullName[:i]
}
fullName = strings.TrimSuffix(fullName, ".")
}
return strings.TrimSuffix(name, ".")
}

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// Copyright 2018, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
// +build purego
package value
import "reflect"
// Pointer is an opaque typed pointer and is guaranteed to be comparable.
type Pointer struct {
p uintptr
t reflect.Type
}
// PointerOf returns a Pointer from v, which must be a
// reflect.Ptr, reflect.Slice, or reflect.Map.
func PointerOf(v reflect.Value) Pointer {
// NOTE: Storing a pointer as an uintptr is technically incorrect as it
// assumes that the GC implementation does not use a moving collector.
return Pointer{v.Pointer(), v.Type()}
}

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// Copyright 2018, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
// +build !purego
package value
import (
"reflect"
"unsafe"
)
// Pointer is an opaque typed pointer and is guaranteed to be comparable.
type Pointer struct {
p unsafe.Pointer
t reflect.Type
}
// PointerOf returns a Pointer from v, which must be a
// reflect.Ptr, reflect.Slice, or reflect.Map.
func PointerOf(v reflect.Value) Pointer {
// The proper representation of a pointer is unsafe.Pointer,
// which is necessary if the GC ever uses a moving collector.
return Pointer{unsafe.Pointer(v.Pointer()), v.Type()}
}

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// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
package value
import (
"fmt"
"math"
"reflect"
"sort"
)
// SortKeys sorts a list of map keys, deduplicating keys if necessary.
// The type of each value must be comparable.
func SortKeys(vs []reflect.Value) []reflect.Value {
if len(vs) == 0 {
return vs
}
// Sort the map keys.
sort.SliceStable(vs, func(i, j int) bool { return isLess(vs[i], vs[j]) })
// Deduplicate keys (fails for NaNs).
vs2 := vs[:1]
for _, v := range vs[1:] {
if isLess(vs2[len(vs2)-1], v) {
vs2 = append(vs2, v)
}
}
return vs2
}
// isLess is a generic function for sorting arbitrary map keys.
// The inputs must be of the same type and must be comparable.
func isLess(x, y reflect.Value) bool {
switch x.Type().Kind() {
case reflect.Bool:
return !x.Bool() && y.Bool()
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return x.Int() < y.Int()
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return x.Uint() < y.Uint()
case reflect.Float32, reflect.Float64:
// NOTE: This does not sort -0 as less than +0
// since Go maps treat -0 and +0 as equal keys.
fx, fy := x.Float(), y.Float()
return fx < fy || math.IsNaN(fx) && !math.IsNaN(fy)
case reflect.Complex64, reflect.Complex128:
cx, cy := x.Complex(), y.Complex()
rx, ix, ry, iy := real(cx), imag(cx), real(cy), imag(cy)
if rx == ry || (math.IsNaN(rx) && math.IsNaN(ry)) {
return ix < iy || math.IsNaN(ix) && !math.IsNaN(iy)
}
return rx < ry || math.IsNaN(rx) && !math.IsNaN(ry)
case reflect.Ptr, reflect.UnsafePointer, reflect.Chan:
return x.Pointer() < y.Pointer()
case reflect.String:
return x.String() < y.String()
case reflect.Array:
for i := 0; i < x.Len(); i++ {
if isLess(x.Index(i), y.Index(i)) {
return true
}
if isLess(y.Index(i), x.Index(i)) {
return false
}
}
return false
case reflect.Struct:
for i := 0; i < x.NumField(); i++ {
if isLess(x.Field(i), y.Field(i)) {
return true
}
if isLess(y.Field(i), x.Field(i)) {
return false
}
}
return false
case reflect.Interface:
vx, vy := x.Elem(), y.Elem()
if !vx.IsValid() || !vy.IsValid() {
return !vx.IsValid() && vy.IsValid()
}
tx, ty := vx.Type(), vy.Type()
if tx == ty {
return isLess(x.Elem(), y.Elem())
}
if tx.Kind() != ty.Kind() {
return vx.Kind() < vy.Kind()
}
if tx.String() != ty.String() {
return tx.String() < ty.String()
}
if tx.PkgPath() != ty.PkgPath() {
return tx.PkgPath() < ty.PkgPath()
}
// This can happen in rare situations, so we fallback to just comparing
// the unique pointer for a reflect.Type. This guarantees deterministic
// ordering within a program, but it is obviously not stable.
return reflect.ValueOf(vx.Type()).Pointer() < reflect.ValueOf(vy.Type()).Pointer()
default:
// Must be Func, Map, or Slice; which are not comparable.
panic(fmt.Sprintf("%T is not comparable", x.Type()))
}
}

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// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
package value
import (
"math"
"reflect"
)
// IsZero reports whether v is the zero value.
// This does not rely on Interface and so can be used on unexported fields.
func IsZero(v reflect.Value) bool {
switch v.Kind() {
case reflect.Bool:
return v.Bool() == false
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return v.Int() == 0
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return v.Uint() == 0
case reflect.Float32, reflect.Float64:
return math.Float64bits(v.Float()) == 0
case reflect.Complex64, reflect.Complex128:
return math.Float64bits(real(v.Complex())) == 0 && math.Float64bits(imag(v.Complex())) == 0
case reflect.String:
return v.String() == ""
case reflect.UnsafePointer:
return v.Pointer() == 0
case reflect.Chan, reflect.Func, reflect.Interface, reflect.Ptr, reflect.Map, reflect.Slice:
return v.IsNil()
case reflect.Array:
for i := 0; i < v.Len(); i++ {
if !IsZero(v.Index(i)) {
return false
}
}
return true
case reflect.Struct:
for i := 0; i < v.NumField(); i++ {
if !IsZero(v.Field(i)) {
return false
}
}
return true
}
return false
}

549
vendor/github.com/google/go-cmp/cmp/options.go generated vendored Normal file
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// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
package cmp
import (
"fmt"
"reflect"
"regexp"
"strings"
"github.com/google/go-cmp/cmp/internal/function"
)
// Option configures for specific behavior of Equal and Diff. In particular,
// the fundamental Option functions (Ignore, Transformer, and Comparer),
// configure how equality is determined.
//
// The fundamental options may be composed with filters (FilterPath and
// FilterValues) to control the scope over which they are applied.
//
// The cmp/cmpopts package provides helper functions for creating options that
// may be used with Equal and Diff.
type Option interface {
// filter applies all filters and returns the option that remains.
// Each option may only read s.curPath and call s.callTTBFunc.
//
// An Options is returned only if multiple comparers or transformers
// can apply simultaneously and will only contain values of those types
// or sub-Options containing values of those types.
filter(s *state, t reflect.Type, vx, vy reflect.Value) applicableOption
}
// applicableOption represents the following types:
// Fundamental: ignore | validator | *comparer | *transformer
// Grouping: Options
type applicableOption interface {
Option
// apply executes the option, which may mutate s or panic.
apply(s *state, vx, vy reflect.Value)
}
// coreOption represents the following types:
// Fundamental: ignore | validator | *comparer | *transformer
// Filters: *pathFilter | *valuesFilter
type coreOption interface {
Option
isCore()
}
type core struct{}
func (core) isCore() {}
// Options is a list of Option values that also satisfies the Option interface.
// Helper comparison packages may return an Options value when packing multiple
// Option values into a single Option. When this package processes an Options,
// it will be implicitly expanded into a flat list.
//
// Applying a filter on an Options is equivalent to applying that same filter
// on all individual options held within.
type Options []Option
func (opts Options) filter(s *state, t reflect.Type, vx, vy reflect.Value) (out applicableOption) {
for _, opt := range opts {
switch opt := opt.filter(s, t, vx, vy); opt.(type) {
case ignore:
return ignore{} // Only ignore can short-circuit evaluation
case validator:
out = validator{} // Takes precedence over comparer or transformer
case *comparer, *transformer, Options:
switch out.(type) {
case nil:
out = opt
case validator:
// Keep validator
case *comparer, *transformer, Options:
out = Options{out, opt} // Conflicting comparers or transformers
}
}
}
return out
}
func (opts Options) apply(s *state, _, _ reflect.Value) {
const warning = "ambiguous set of applicable options"
const help = "consider using filters to ensure at most one Comparer or Transformer may apply"
var ss []string
for _, opt := range flattenOptions(nil, opts) {
ss = append(ss, fmt.Sprint(opt))
}
set := strings.Join(ss, "\n\t")
panic(fmt.Sprintf("%s at %#v:\n\t%s\n%s", warning, s.curPath, set, help))
}
func (opts Options) String() string {
var ss []string
for _, opt := range opts {
ss = append(ss, fmt.Sprint(opt))
}
return fmt.Sprintf("Options{%s}", strings.Join(ss, ", "))
}
// FilterPath returns a new Option where opt is only evaluated if filter f
// returns true for the current Path in the value tree.
//
// This filter is called even if a slice element or map entry is missing and
// provides an opportunity to ignore such cases. The filter function must be
// symmetric such that the filter result is identical regardless of whether the
// missing value is from x or y.
//
// The option passed in may be an Ignore, Transformer, Comparer, Options, or
// a previously filtered Option.
func FilterPath(f func(Path) bool, opt Option) Option {
if f == nil {
panic("invalid path filter function")
}
if opt := normalizeOption(opt); opt != nil {
return &pathFilter{fnc: f, opt: opt}
}
return nil
}
type pathFilter struct {
core
fnc func(Path) bool
opt Option
}
func (f pathFilter) filter(s *state, t reflect.Type, vx, vy reflect.Value) applicableOption {
if f.fnc(s.curPath) {
return f.opt.filter(s, t, vx, vy)
}
return nil
}
func (f pathFilter) String() string {
return fmt.Sprintf("FilterPath(%s, %v)", function.NameOf(reflect.ValueOf(f.fnc)), f.opt)
}
// FilterValues returns a new Option where opt is only evaluated if filter f,
// which is a function of the form "func(T, T) bool", returns true for the
// current pair of values being compared. If either value is invalid or
// the type of the values is not assignable to T, then this filter implicitly
// returns false.
//
// The filter function must be
// symmetric (i.e., agnostic to the order of the inputs) and
// deterministic (i.e., produces the same result when given the same inputs).
// If T is an interface, it is possible that f is called with two values with
// different concrete types that both implement T.
//
// The option passed in may be an Ignore, Transformer, Comparer, Options, or
// a previously filtered Option.
func FilterValues(f interface{}, opt Option) Option {
v := reflect.ValueOf(f)
if !function.IsType(v.Type(), function.ValueFilter) || v.IsNil() {
panic(fmt.Sprintf("invalid values filter function: %T", f))
}
if opt := normalizeOption(opt); opt != nil {
vf := &valuesFilter{fnc: v, opt: opt}
if ti := v.Type().In(0); ti.Kind() != reflect.Interface || ti.NumMethod() > 0 {
vf.typ = ti
}
return vf
}
return nil
}
type valuesFilter struct {
core
typ reflect.Type // T
fnc reflect.Value // func(T, T) bool
opt Option
}
func (f valuesFilter) filter(s *state, t reflect.Type, vx, vy reflect.Value) applicableOption {
if !vx.IsValid() || !vx.CanInterface() || !vy.IsValid() || !vy.CanInterface() {
return nil
}
if (f.typ == nil || t.AssignableTo(f.typ)) && s.callTTBFunc(f.fnc, vx, vy) {
return f.opt.filter(s, t, vx, vy)
}
return nil
}
func (f valuesFilter) String() string {
return fmt.Sprintf("FilterValues(%s, %v)", function.NameOf(f.fnc), f.opt)
}
// Ignore is an Option that causes all comparisons to be ignored.
// This value is intended to be combined with FilterPath or FilterValues.
// It is an error to pass an unfiltered Ignore option to Equal.
func Ignore() Option { return ignore{} }
type ignore struct{ core }
func (ignore) isFiltered() bool { return false }
func (ignore) filter(_ *state, _ reflect.Type, _, _ reflect.Value) applicableOption { return ignore{} }
func (ignore) apply(s *state, _, _ reflect.Value) { s.report(true, reportByIgnore) }
func (ignore) String() string { return "Ignore()" }
// validator is a sentinel Option type to indicate that some options could not
// be evaluated due to unexported fields, missing slice elements, or
// missing map entries. Both values are validator only for unexported fields.
type validator struct{ core }
func (validator) filter(_ *state, _ reflect.Type, vx, vy reflect.Value) applicableOption {
if !vx.IsValid() || !vy.IsValid() {
return validator{}
}
if !vx.CanInterface() || !vy.CanInterface() {
return validator{}
}
return nil
}
func (validator) apply(s *state, vx, vy reflect.Value) {
// Implies missing slice element or map entry.
if !vx.IsValid() || !vy.IsValid() {
s.report(vx.IsValid() == vy.IsValid(), 0)
return
}
// Unable to Interface implies unexported field without visibility access.
if !vx.CanInterface() || !vy.CanInterface() {
const help = "consider using a custom Comparer; if you control the implementation of type, you can also consider using an Exporter, AllowUnexported, or cmpopts.IgnoreUnexported"
var name string
if t := s.curPath.Index(-2).Type(); t.Name() != "" {
// Named type with unexported fields.
name = fmt.Sprintf("%q.%v", t.PkgPath(), t.Name()) // e.g., "path/to/package".MyType
} else {
// Unnamed type with unexported fields. Derive PkgPath from field.
var pkgPath string
for i := 0; i < t.NumField() && pkgPath == ""; i++ {
pkgPath = t.Field(i).PkgPath
}
name = fmt.Sprintf("%q.(%v)", pkgPath, t.String()) // e.g., "path/to/package".(struct { a int })
}
panic(fmt.Sprintf("cannot handle unexported field at %#v:\n\t%v\n%s", s.curPath, name, help))
}
panic("not reachable")
}
// identRx represents a valid identifier according to the Go specification.
const identRx = `[_\p{L}][_\p{L}\p{N}]*`
var identsRx = regexp.MustCompile(`^` + identRx + `(\.` + identRx + `)*$`)
// Transformer returns an Option that applies a transformation function that
// converts values of a certain type into that of another.
//
// The transformer f must be a function "func(T) R" that converts values of
// type T to those of type R and is implicitly filtered to input values
// assignable to T. The transformer must not mutate T in any way.
//
// To help prevent some cases of infinite recursive cycles applying the
// same transform to the output of itself (e.g., in the case where the
// input and output types are the same), an implicit filter is added such that
// a transformer is applicable only if that exact transformer is not already
// in the tail of the Path since the last non-Transform step.
// For situations where the implicit filter is still insufficient,
// consider using cmpopts.AcyclicTransformer, which adds a filter
// to prevent the transformer from being recursively applied upon itself.
//
// The name is a user provided label that is used as the Transform.Name in the
// transformation PathStep (and eventually shown in the Diff output).
// The name must be a valid identifier or qualified identifier in Go syntax.
// If empty, an arbitrary name is used.
func Transformer(name string, f interface{}) Option {
v := reflect.ValueOf(f)
if !function.IsType(v.Type(), function.Transformer) || v.IsNil() {
panic(fmt.Sprintf("invalid transformer function: %T", f))
}
if name == "" {
name = function.NameOf(v)
if !identsRx.MatchString(name) {
name = "λ" // Lambda-symbol as placeholder name
}
} else if !identsRx.MatchString(name) {
panic(fmt.Sprintf("invalid name: %q", name))
}
tr := &transformer{name: name, fnc: reflect.ValueOf(f)}
if ti := v.Type().In(0); ti.Kind() != reflect.Interface || ti.NumMethod() > 0 {
tr.typ = ti
}
return tr
}
type transformer struct {
core
name string
typ reflect.Type // T
fnc reflect.Value // func(T) R
}
func (tr *transformer) isFiltered() bool { return tr.typ != nil }
func (tr *transformer) filter(s *state, t reflect.Type, _, _ reflect.Value) applicableOption {
for i := len(s.curPath) - 1; i >= 0; i-- {
if t, ok := s.curPath[i].(Transform); !ok {
break // Hit most recent non-Transform step
} else if tr == t.trans {
return nil // Cannot directly use same Transform
}
}
if tr.typ == nil || t.AssignableTo(tr.typ) {
return tr
}
return nil
}
func (tr *transformer) apply(s *state, vx, vy reflect.Value) {
step := Transform{&transform{pathStep{typ: tr.fnc.Type().Out(0)}, tr}}
vvx := s.callTRFunc(tr.fnc, vx, step)
vvy := s.callTRFunc(tr.fnc, vy, step)
step.vx, step.vy = vvx, vvy
s.compareAny(step)
}
func (tr transformer) String() string {
return fmt.Sprintf("Transformer(%s, %s)", tr.name, function.NameOf(tr.fnc))
}
// Comparer returns an Option that determines whether two values are equal
// to each other.
//
// The comparer f must be a function "func(T, T) bool" and is implicitly
// filtered to input values assignable to T. If T is an interface, it is
// possible that f is called with two values of different concrete types that
// both implement T.
//
// The equality function must be:
// • Symmetric: equal(x, y) == equal(y, x)
// • Deterministic: equal(x, y) == equal(x, y)
// • Pure: equal(x, y) does not modify x or y
func Comparer(f interface{}) Option {
v := reflect.ValueOf(f)
if !function.IsType(v.Type(), function.Equal) || v.IsNil() {
panic(fmt.Sprintf("invalid comparer function: %T", f))
}
cm := &comparer{fnc: v}
if ti := v.Type().In(0); ti.Kind() != reflect.Interface || ti.NumMethod() > 0 {
cm.typ = ti
}
return cm
}
type comparer struct {
core
typ reflect.Type // T
fnc reflect.Value // func(T, T) bool
}
func (cm *comparer) isFiltered() bool { return cm.typ != nil }
func (cm *comparer) filter(_ *state, t reflect.Type, _, _ reflect.Value) applicableOption {
if cm.typ == nil || t.AssignableTo(cm.typ) {
return cm
}
return nil
}
func (cm *comparer) apply(s *state, vx, vy reflect.Value) {
eq := s.callTTBFunc(cm.fnc, vx, vy)
s.report(eq, reportByFunc)
}
func (cm comparer) String() string {
return fmt.Sprintf("Comparer(%s)", function.NameOf(cm.fnc))
}
// Exporter returns an Option that specifies whether Equal is allowed to
// introspect into the unexported fields of certain struct types.
//
// Users of this option must understand that comparing on unexported fields
// from external packages is not safe since changes in the internal
// implementation of some external package may cause the result of Equal
// to unexpectedly change. However, it may be valid to use this option on types
// defined in an internal package where the semantic meaning of an unexported
// field is in the control of the user.
//
// In many cases, a custom Comparer should be used instead that defines
// equality as a function of the public API of a type rather than the underlying
// unexported implementation.
//
// For example, the reflect.Type documentation defines equality to be determined
// by the == operator on the interface (essentially performing a shallow pointer
// comparison) and most attempts to compare *regexp.Regexp types are interested
// in only checking that the regular expression strings are equal.
// Both of these are accomplished using Comparers:
//
// Comparer(func(x, y reflect.Type) bool { return x == y })
// Comparer(func(x, y *regexp.Regexp) bool { return x.String() == y.String() })
//
// In other cases, the cmpopts.IgnoreUnexported option can be used to ignore
// all unexported fields on specified struct types.
func Exporter(f func(reflect.Type) bool) Option {
if !supportExporters {
panic("Exporter is not supported on purego builds")
}
return exporter(f)
}
type exporter func(reflect.Type) bool
func (exporter) filter(_ *state, _ reflect.Type, _, _ reflect.Value) applicableOption {
panic("not implemented")
}
// AllowUnexported returns an Options that allows Equal to forcibly introspect
// unexported fields of the specified struct types.
//
// See Exporter for the proper use of this option.
func AllowUnexported(types ...interface{}) Option {
m := make(map[reflect.Type]bool)
for _, typ := range types {
t := reflect.TypeOf(typ)
if t.Kind() != reflect.Struct {
panic(fmt.Sprintf("invalid struct type: %T", typ))
}
m[t] = true
}
return exporter(func(t reflect.Type) bool { return m[t] })
}
// Result represents the comparison result for a single node and
// is provided by cmp when calling Result (see Reporter).
type Result struct {
_ [0]func() // Make Result incomparable
flags resultFlags
}
// Equal reports whether the node was determined to be equal or not.
// As a special case, ignored nodes are considered equal.
func (r Result) Equal() bool {
return r.flags&(reportEqual|reportByIgnore) != 0
}
// ByIgnore reports whether the node is equal because it was ignored.
// This never reports true if Equal reports false.
func (r Result) ByIgnore() bool {
return r.flags&reportByIgnore != 0
}
// ByMethod reports whether the Equal method determined equality.
func (r Result) ByMethod() bool {
return r.flags&reportByMethod != 0
}
// ByFunc reports whether a Comparer function determined equality.
func (r Result) ByFunc() bool {
return r.flags&reportByFunc != 0
}
// ByCycle reports whether a reference cycle was detected.
func (r Result) ByCycle() bool {
return r.flags&reportByCycle != 0
}
type resultFlags uint
const (
_ resultFlags = (1 << iota) / 2
reportEqual
reportUnequal
reportByIgnore
reportByMethod
reportByFunc
reportByCycle
)
// Reporter is an Option that can be passed to Equal. When Equal traverses
// the value trees, it calls PushStep as it descends into each node in the
// tree and PopStep as it ascend out of the node. The leaves of the tree are
// either compared (determined to be equal or not equal) or ignored and reported
// as such by calling the Report method.
func Reporter(r interface {
// PushStep is called when a tree-traversal operation is performed.
// The PathStep itself is only valid until the step is popped.
// The PathStep.Values are valid for the duration of the entire traversal
// and must not be mutated.
//
// Equal always calls PushStep at the start to provide an operation-less
// PathStep used to report the root values.
//
// Within a slice, the exact set of inserted, removed, or modified elements
// is unspecified and may change in future implementations.
// The entries of a map are iterated through in an unspecified order.
PushStep(PathStep)
// Report is called exactly once on leaf nodes to report whether the
// comparison identified the node as equal, unequal, or ignored.
// A leaf node is one that is immediately preceded by and followed by
// a pair of PushStep and PopStep calls.
Report(Result)
// PopStep ascends back up the value tree.
// There is always a matching pop call for every push call.
PopStep()
}) Option {
return reporter{r}
}
type reporter struct{ reporterIface }
type reporterIface interface {
PushStep(PathStep)
Report(Result)
PopStep()
}
func (reporter) filter(_ *state, _ reflect.Type, _, _ reflect.Value) applicableOption {
panic("not implemented")
}
// normalizeOption normalizes the input options such that all Options groups
// are flattened and groups with a single element are reduced to that element.
// Only coreOptions and Options containing coreOptions are allowed.
func normalizeOption(src Option) Option {
switch opts := flattenOptions(nil, Options{src}); len(opts) {
case 0:
return nil
case 1:
return opts[0]
default:
return opts
}
}
// flattenOptions copies all options in src to dst as a flat list.
// Only coreOptions and Options containing coreOptions are allowed.
func flattenOptions(dst, src Options) Options {
for _, opt := range src {
switch opt := opt.(type) {
case nil:
continue
case Options:
dst = flattenOptions(dst, opt)
case coreOption:
dst = append(dst, opt)
default:
panic(fmt.Sprintf("invalid option type: %T", opt))
}
}
return dst
}

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@ -0,0 +1,377 @@
// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
package cmp
import (
"fmt"
"reflect"
"strings"
"unicode"
"unicode/utf8"
"github.com/google/go-cmp/cmp/internal/value"
)
// Path is a list of PathSteps describing the sequence of operations to get
// from some root type to the current position in the value tree.
// The first Path element is always an operation-less PathStep that exists
// simply to identify the initial type.
//
// When traversing structs with embedded structs, the embedded struct will
// always be accessed as a field before traversing the fields of the
// embedded struct themselves. That is, an exported field from the
// embedded struct will never be accessed directly from the parent struct.
type Path []PathStep
// PathStep is a union-type for specific operations to traverse
// a value's tree structure. Users of this package never need to implement
// these types as values of this type will be returned by this package.
//
// Implementations of this interface are
// StructField, SliceIndex, MapIndex, Indirect, TypeAssertion, and Transform.
type PathStep interface {
String() string
// Type is the resulting type after performing the path step.
Type() reflect.Type
// Values is the resulting values after performing the path step.
// The type of each valid value is guaranteed to be identical to Type.
//
// In some cases, one or both may be invalid or have restrictions:
// • For StructField, both are not interface-able if the current field
// is unexported and the struct type is not explicitly permitted by
// an Exporter to traverse unexported fields.
// • For SliceIndex, one may be invalid if an element is missing from
// either the x or y slice.
// • For MapIndex, one may be invalid if an entry is missing from
// either the x or y map.
//
// The provided values must not be mutated.
Values() (vx, vy reflect.Value)
}
var (
_ PathStep = StructField{}
_ PathStep = SliceIndex{}
_ PathStep = MapIndex{}
_ PathStep = Indirect{}
_ PathStep = TypeAssertion{}
_ PathStep = Transform{}
)
func (pa *Path) push(s PathStep) {
*pa = append(*pa, s)
}
func (pa *Path) pop() {
*pa = (*pa)[:len(*pa)-1]
}
// Last returns the last PathStep in the Path.
// If the path is empty, this returns a non-nil PathStep that reports a nil Type.
func (pa Path) Last() PathStep {
return pa.Index(-1)
}
// Index returns the ith step in the Path and supports negative indexing.
// A negative index starts counting from the tail of the Path such that -1
// refers to the last step, -2 refers to the second-to-last step, and so on.
// If index is invalid, this returns a non-nil PathStep that reports a nil Type.
func (pa Path) Index(i int) PathStep {
if i < 0 {
i = len(pa) + i
}
if i < 0 || i >= len(pa) {
return pathStep{}
}
return pa[i]
}
// String returns the simplified path to a node.
// The simplified path only contains struct field accesses.
//
// For example:
// MyMap.MySlices.MyField
func (pa Path) String() string {
var ss []string
for _, s := range pa {
if _, ok := s.(StructField); ok {
ss = append(ss, s.String())
}
}
return strings.TrimPrefix(strings.Join(ss, ""), ".")
}
// GoString returns the path to a specific node using Go syntax.
//
// For example:
// (*root.MyMap["key"].(*mypkg.MyStruct).MySlices)[2][3].MyField
func (pa Path) GoString() string {
var ssPre, ssPost []string
var numIndirect int
for i, s := range pa {
var nextStep PathStep
if i+1 < len(pa) {
nextStep = pa[i+1]
}
switch s := s.(type) {
case Indirect:
numIndirect++
pPre, pPost := "(", ")"
switch nextStep.(type) {
case Indirect:
continue // Next step is indirection, so let them batch up
case StructField:
numIndirect-- // Automatic indirection on struct fields
case nil:
pPre, pPost = "", "" // Last step; no need for parenthesis
}
if numIndirect > 0 {
ssPre = append(ssPre, pPre+strings.Repeat("*", numIndirect))
ssPost = append(ssPost, pPost)
}
numIndirect = 0
continue
case Transform:
ssPre = append(ssPre, s.trans.name+"(")
ssPost = append(ssPost, ")")
continue
}
ssPost = append(ssPost, s.String())
}
for i, j := 0, len(ssPre)-1; i < j; i, j = i+1, j-1 {
ssPre[i], ssPre[j] = ssPre[j], ssPre[i]
}
return strings.Join(ssPre, "") + strings.Join(ssPost, "")
}
type pathStep struct {
typ reflect.Type
vx, vy reflect.Value
}
func (ps pathStep) Type() reflect.Type { return ps.typ }
func (ps pathStep) Values() (vx, vy reflect.Value) { return ps.vx, ps.vy }
func (ps pathStep) String() string {
if ps.typ == nil {
return "<nil>"
}
s := ps.typ.String()
if s == "" || strings.ContainsAny(s, "{}\n") {
return "root" // Type too simple or complex to print
}
return fmt.Sprintf("{%s}", s)
}
// StructField represents a struct field access on a field called Name.
type StructField struct{ *structField }
type structField struct {
pathStep
name string
idx int
// These fields are used for forcibly accessing an unexported field.
// pvx, pvy, and field are only valid if unexported is true.
unexported bool
mayForce bool // Forcibly allow visibility
pvx, pvy reflect.Value // Parent values
field reflect.StructField // Field information
}
func (sf StructField) Type() reflect.Type { return sf.typ }
func (sf StructField) Values() (vx, vy reflect.Value) {
if !sf.unexported {
return sf.vx, sf.vy // CanInterface reports true
}
// Forcibly obtain read-write access to an unexported struct field.
if sf.mayForce {
vx = retrieveUnexportedField(sf.pvx, sf.field)
vy = retrieveUnexportedField(sf.pvy, sf.field)
return vx, vy // CanInterface reports true
}
return sf.vx, sf.vy // CanInterface reports false
}
func (sf StructField) String() string { return fmt.Sprintf(".%s", sf.name) }
// Name is the field name.
func (sf StructField) Name() string { return sf.name }
// Index is the index of the field in the parent struct type.
// See reflect.Type.Field.
func (sf StructField) Index() int { return sf.idx }
// SliceIndex is an index operation on a slice or array at some index Key.
type SliceIndex struct{ *sliceIndex }
type sliceIndex struct {
pathStep
xkey, ykey int
isSlice bool // False for reflect.Array
}
func (si SliceIndex) Type() reflect.Type { return si.typ }
func (si SliceIndex) Values() (vx, vy reflect.Value) { return si.vx, si.vy }
func (si SliceIndex) String() string {
switch {
case si.xkey == si.ykey:
return fmt.Sprintf("[%d]", si.xkey)
case si.ykey == -1:
// [5->?] means "I don't know where X[5] went"
return fmt.Sprintf("[%d->?]", si.xkey)
case si.xkey == -1:
// [?->3] means "I don't know where Y[3] came from"
return fmt.Sprintf("[?->%d]", si.ykey)
default:
// [5->3] means "X[5] moved to Y[3]"
return fmt.Sprintf("[%d->%d]", si.xkey, si.ykey)
}
}
// Key is the index key; it may return -1 if in a split state
func (si SliceIndex) Key() int {
if si.xkey != si.ykey {
return -1
}
return si.xkey
}
// SplitKeys are the indexes for indexing into slices in the
// x and y values, respectively. These indexes may differ due to the
// insertion or removal of an element in one of the slices, causing
// all of the indexes to be shifted. If an index is -1, then that
// indicates that the element does not exist in the associated slice.
//
// Key is guaranteed to return -1 if and only if the indexes returned
// by SplitKeys are not the same. SplitKeys will never return -1 for
// both indexes.
func (si SliceIndex) SplitKeys() (ix, iy int) { return si.xkey, si.ykey }
// MapIndex is an index operation on a map at some index Key.
type MapIndex struct{ *mapIndex }
type mapIndex struct {
pathStep
key reflect.Value
}
func (mi MapIndex) Type() reflect.Type { return mi.typ }
func (mi MapIndex) Values() (vx, vy reflect.Value) { return mi.vx, mi.vy }
func (mi MapIndex) String() string { return fmt.Sprintf("[%#v]", mi.key) }
// Key is the value of the map key.
func (mi MapIndex) Key() reflect.Value { return mi.key }
// Indirect represents pointer indirection on the parent type.
type Indirect struct{ *indirect }
type indirect struct {
pathStep
}
func (in Indirect) Type() reflect.Type { return in.typ }
func (in Indirect) Values() (vx, vy reflect.Value) { return in.vx, in.vy }
func (in Indirect) String() string { return "*" }
// TypeAssertion represents a type assertion on an interface.
type TypeAssertion struct{ *typeAssertion }
type typeAssertion struct {
pathStep
}
func (ta TypeAssertion) Type() reflect.Type { return ta.typ }
func (ta TypeAssertion) Values() (vx, vy reflect.Value) { return ta.vx, ta.vy }
func (ta TypeAssertion) String() string { return fmt.Sprintf(".(%v)", ta.typ) }
// Transform is a transformation from the parent type to the current type.
type Transform struct{ *transform }
type transform struct {
pathStep
trans *transformer
}
func (tf Transform) Type() reflect.Type { return tf.typ }
func (tf Transform) Values() (vx, vy reflect.Value) { return tf.vx, tf.vy }
func (tf Transform) String() string { return fmt.Sprintf("%s()", tf.trans.name) }
// Name is the name of the Transformer.
func (tf Transform) Name() string { return tf.trans.name }
// Func is the function pointer to the transformer function.
func (tf Transform) Func() reflect.Value { return tf.trans.fnc }
// Option returns the originally constructed Transformer option.
// The == operator can be used to detect the exact option used.
func (tf Transform) Option() Option { return tf.trans }
// pointerPath represents a dual-stack of pointers encountered when
// recursively traversing the x and y values. This data structure supports
// detection of cycles and determining whether the cycles are equal.
// In Go, cycles can occur via pointers, slices, and maps.
//
// The pointerPath uses a map to represent a stack; where descension into a
// pointer pushes the address onto the stack, and ascension from a pointer
// pops the address from the stack. Thus, when traversing into a pointer from
// reflect.Ptr, reflect.Slice element, or reflect.Map, we can detect cycles
// by checking whether the pointer has already been visited. The cycle detection
// uses a seperate stack for the x and y values.
//
// If a cycle is detected we need to determine whether the two pointers
// should be considered equal. The definition of equality chosen by Equal
// requires two graphs to have the same structure. To determine this, both the
// x and y values must have a cycle where the previous pointers were also
// encountered together as a pair.
//
// Semantically, this is equivalent to augmenting Indirect, SliceIndex, and
// MapIndex with pointer information for the x and y values.
// Suppose px and py are two pointers to compare, we then search the
// Path for whether px was ever encountered in the Path history of x, and
// similarly so with py. If either side has a cycle, the comparison is only
// equal if both px and py have a cycle resulting from the same PathStep.
//
// Using a map as a stack is more performant as we can perform cycle detection
// in O(1) instead of O(N) where N is len(Path).
type pointerPath struct {
// mx is keyed by x pointers, where the value is the associated y pointer.
mx map[value.Pointer]value.Pointer
// my is keyed by y pointers, where the value is the associated x pointer.
my map[value.Pointer]value.Pointer
}
func (p *pointerPath) Init() {
p.mx = make(map[value.Pointer]value.Pointer)
p.my = make(map[value.Pointer]value.Pointer)
}
// Push indicates intent to descend into pointers vx and vy where
// visited reports whether either has been seen before. If visited before,
// equal reports whether both pointers were encountered together.
// Pop must be called if and only if the pointers were never visited.
//
// The pointers vx and vy must be a reflect.Ptr, reflect.Slice, or reflect.Map
// and be non-nil.
func (p pointerPath) Push(vx, vy reflect.Value) (equal, visited bool) {
px := value.PointerOf(vx)
py := value.PointerOf(vy)
_, ok1 := p.mx[px]
_, ok2 := p.my[py]
if ok1 || ok2 {
equal = p.mx[px] == py && p.my[py] == px // Pointers paired together
return equal, true
}
p.mx[px] = py
p.my[py] = px
return false, false
}
// Pop ascends from pointers vx and vy.
func (p pointerPath) Pop(vx, vy reflect.Value) {
delete(p.mx, value.PointerOf(vx))
delete(p.my, value.PointerOf(vy))
}
// isExported reports whether the identifier is exported.
func isExported(id string) bool {
r, _ := utf8.DecodeRuneInString(id)
return unicode.IsUpper(r)
}

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// Copyright 2017, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
package cmp
// defaultReporter implements the reporter interface.
//
// As Equal serially calls the PushStep, Report, and PopStep methods, the
// defaultReporter constructs a tree-based representation of the compared value
// and the result of each comparison (see valueNode).
//
// When the String method is called, the FormatDiff method transforms the
// valueNode tree into a textNode tree, which is a tree-based representation
// of the textual output (see textNode).
//
// Lastly, the textNode.String method produces the final report as a string.
type defaultReporter struct {
root *valueNode
curr *valueNode
}
func (r *defaultReporter) PushStep(ps PathStep) {
r.curr = r.curr.PushStep(ps)
if r.root == nil {
r.root = r.curr
}
}
func (r *defaultReporter) Report(rs Result) {
r.curr.Report(rs)
}
func (r *defaultReporter) PopStep() {
r.curr = r.curr.PopStep()
}
// String provides a full report of the differences detected as a structured
// literal in pseudo-Go syntax. String may only be called after the entire tree
// has been traversed.
func (r *defaultReporter) String() string {
assert(r.root != nil && r.curr == nil)
if r.root.NumDiff == 0 {
return ""
}
return formatOptions{}.FormatDiff(r.root).String()
}
func assert(ok bool) {
if !ok {
panic("assertion failure")
}
}

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// Copyright 2019, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
package cmp
import (
"fmt"
"reflect"
"github.com/google/go-cmp/cmp/internal/value"
)
// TODO: Enforce limits?
// * Enforce maximum number of records to print per node?
// * Enforce maximum size in bytes allowed?
// * As a heuristic, use less verbosity for equal nodes than unequal nodes.
// TODO: Enforce unique outputs?
// * Avoid Stringer methods if it results in same output?
// * Print pointer address if outputs still equal?
// numContextRecords is the number of surrounding equal records to print.
const numContextRecords = 2
type diffMode byte
const (
diffUnknown diffMode = 0
diffIdentical diffMode = ' '
diffRemoved diffMode = '-'
diffInserted diffMode = '+'
)
type typeMode int
const (
// emitType always prints the type.
emitType typeMode = iota
// elideType never prints the type.
elideType
// autoType prints the type only for composite kinds
// (i.e., structs, slices, arrays, and maps).
autoType
)
type formatOptions struct {
// DiffMode controls the output mode of FormatDiff.
//
// If diffUnknown, then produce a diff of the x and y values.
// If diffIdentical, then emit values as if they were equal.
// If diffRemoved, then only emit x values (ignoring y values).
// If diffInserted, then only emit y values (ignoring x values).
DiffMode diffMode
// TypeMode controls whether to print the type for the current node.
//
// As a general rule of thumb, we always print the type of the next node
// after an interface, and always elide the type of the next node after
// a slice or map node.
TypeMode typeMode
// formatValueOptions are options specific to printing reflect.Values.
formatValueOptions
}
func (opts formatOptions) WithDiffMode(d diffMode) formatOptions {
opts.DiffMode = d
return opts
}
func (opts formatOptions) WithTypeMode(t typeMode) formatOptions {
opts.TypeMode = t
return opts
}
// FormatDiff converts a valueNode tree into a textNode tree, where the later
// is a textual representation of the differences detected in the former.
func (opts formatOptions) FormatDiff(v *valueNode) textNode {
// Check whether we have specialized formatting for this node.
// This is not necessary, but helpful for producing more readable outputs.
if opts.CanFormatDiffSlice(v) {
return opts.FormatDiffSlice(v)
}
var withinSlice bool
if v.parent != nil && (v.parent.Type.Kind() == reflect.Slice || v.parent.Type.Kind() == reflect.Array) {
withinSlice = true
}
// For leaf nodes, format the value based on the reflect.Values alone.
if v.MaxDepth == 0 {
switch opts.DiffMode {
case diffUnknown, diffIdentical:
// Format Equal.
if v.NumDiff == 0 {
outx := opts.FormatValue(v.ValueX, withinSlice, visitedPointers{})
outy := opts.FormatValue(v.ValueY, withinSlice, visitedPointers{})
if v.NumIgnored > 0 && v.NumSame == 0 {
return textEllipsis
} else if outx.Len() < outy.Len() {
return outx
} else {
return outy
}
}
// Format unequal.
assert(opts.DiffMode == diffUnknown)
var list textList
outx := opts.WithTypeMode(elideType).FormatValue(v.ValueX, withinSlice, visitedPointers{})
outy := opts.WithTypeMode(elideType).FormatValue(v.ValueY, withinSlice, visitedPointers{})
if outx != nil {
list = append(list, textRecord{Diff: '-', Value: outx})
}
if outy != nil {
list = append(list, textRecord{Diff: '+', Value: outy})
}
return opts.WithTypeMode(emitType).FormatType(v.Type, list)
case diffRemoved:
return opts.FormatValue(v.ValueX, withinSlice, visitedPointers{})
case diffInserted:
return opts.FormatValue(v.ValueY, withinSlice, visitedPointers{})
default:
panic("invalid diff mode")
}
}
// Descend into the child value node.
if v.TransformerName != "" {
out := opts.WithTypeMode(emitType).FormatDiff(v.Value)
out = textWrap{"Inverse(" + v.TransformerName + ", ", out, ")"}
return opts.FormatType(v.Type, out)
} else {
switch k := v.Type.Kind(); k {
case reflect.Struct, reflect.Array, reflect.Slice, reflect.Map:
return opts.FormatType(v.Type, opts.formatDiffList(v.Records, k))
case reflect.Ptr:
return textWrap{"&", opts.FormatDiff(v.Value), ""}
case reflect.Interface:
return opts.WithTypeMode(emitType).FormatDiff(v.Value)
default:
panic(fmt.Sprintf("%v cannot have children", k))
}
}
}
func (opts formatOptions) formatDiffList(recs []reportRecord, k reflect.Kind) textNode {
// Derive record name based on the data structure kind.
var name string
var formatKey func(reflect.Value) string
switch k {
case reflect.Struct:
name = "field"
opts = opts.WithTypeMode(autoType)
formatKey = func(v reflect.Value) string { return v.String() }
case reflect.Slice, reflect.Array:
name = "element"
opts = opts.WithTypeMode(elideType)
formatKey = func(reflect.Value) string { return "" }
case reflect.Map:
name = "entry"
opts = opts.WithTypeMode(elideType)
formatKey = formatMapKey
}
// Handle unification.
switch opts.DiffMode {
case diffIdentical, diffRemoved, diffInserted:
var list textList
var deferredEllipsis bool // Add final "..." to indicate records were dropped
for _, r := range recs {
// Elide struct fields that are zero value.
if k == reflect.Struct {
var isZero bool
switch opts.DiffMode {
case diffIdentical:
isZero = value.IsZero(r.Value.ValueX) || value.IsZero(r.Value.ValueY)
case diffRemoved:
isZero = value.IsZero(r.Value.ValueX)
case diffInserted:
isZero = value.IsZero(r.Value.ValueY)
}
if isZero {
continue
}
}
// Elide ignored nodes.
if r.Value.NumIgnored > 0 && r.Value.NumSame+r.Value.NumDiff == 0 {
deferredEllipsis = !(k == reflect.Slice || k == reflect.Array)
if !deferredEllipsis {
list.AppendEllipsis(diffStats{})
}
continue
}
if out := opts.FormatDiff(r.Value); out != nil {
list = append(list, textRecord{Key: formatKey(r.Key), Value: out})
}
}
if deferredEllipsis {
list.AppendEllipsis(diffStats{})
}
return textWrap{"{", list, "}"}
case diffUnknown:
default:
panic("invalid diff mode")
}
// Handle differencing.
var list textList
groups := coalesceAdjacentRecords(name, recs)
for i, ds := range groups {
// Handle equal records.
if ds.NumDiff() == 0 {
// Compute the number of leading and trailing records to print.
var numLo, numHi int
numEqual := ds.NumIgnored + ds.NumIdentical
for numLo < numContextRecords && numLo+numHi < numEqual && i != 0 {
if r := recs[numLo].Value; r.NumIgnored > 0 && r.NumSame+r.NumDiff == 0 {
break
}
numLo++
}
for numHi < numContextRecords && numLo+numHi < numEqual && i != len(groups)-1 {
if r := recs[numEqual-numHi-1].Value; r.NumIgnored > 0 && r.NumSame+r.NumDiff == 0 {
break
}
numHi++
}
if numEqual-(numLo+numHi) == 1 && ds.NumIgnored == 0 {
numHi++ // Avoid pointless coalescing of a single equal record
}
// Format the equal values.
for _, r := range recs[:numLo] {
out := opts.WithDiffMode(diffIdentical).FormatDiff(r.Value)
list = append(list, textRecord{Key: formatKey(r.Key), Value: out})
}
if numEqual > numLo+numHi {
ds.NumIdentical -= numLo + numHi
list.AppendEllipsis(ds)
}
for _, r := range recs[numEqual-numHi : numEqual] {
out := opts.WithDiffMode(diffIdentical).FormatDiff(r.Value)
list = append(list, textRecord{Key: formatKey(r.Key), Value: out})
}
recs = recs[numEqual:]
continue
}
// Handle unequal records.
for _, r := range recs[:ds.NumDiff()] {
switch {
case opts.CanFormatDiffSlice(r.Value):
out := opts.FormatDiffSlice(r.Value)
list = append(list, textRecord{Key: formatKey(r.Key), Value: out})
case r.Value.NumChildren == r.Value.MaxDepth:
outx := opts.WithDiffMode(diffRemoved).FormatDiff(r.Value)
outy := opts.WithDiffMode(diffInserted).FormatDiff(r.Value)
if outx != nil {
list = append(list, textRecord{Diff: diffRemoved, Key: formatKey(r.Key), Value: outx})
}
if outy != nil {
list = append(list, textRecord{Diff: diffInserted, Key: formatKey(r.Key), Value: outy})
}
default:
out := opts.FormatDiff(r.Value)
list = append(list, textRecord{Key: formatKey(r.Key), Value: out})
}
}
recs = recs[ds.NumDiff():]
}
assert(len(recs) == 0)
return textWrap{"{", list, "}"}
}
// coalesceAdjacentRecords coalesces the list of records into groups of
// adjacent equal, or unequal counts.
func coalesceAdjacentRecords(name string, recs []reportRecord) (groups []diffStats) {
var prevCase int // Arbitrary index into which case last occurred
lastStats := func(i int) *diffStats {
if prevCase != i {
groups = append(groups, diffStats{Name: name})
prevCase = i
}
return &groups[len(groups)-1]
}
for _, r := range recs {
switch rv := r.Value; {
case rv.NumIgnored > 0 && rv.NumSame+rv.NumDiff == 0:
lastStats(1).NumIgnored++
case rv.NumDiff == 0:
lastStats(1).NumIdentical++
case rv.NumDiff > 0 && !rv.ValueY.IsValid():
lastStats(2).NumRemoved++
case rv.NumDiff > 0 && !rv.ValueX.IsValid():
lastStats(2).NumInserted++
default:
lastStats(2).NumModified++
}
}
return groups
}

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// Copyright 2019, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
package cmp
import (
"fmt"
"reflect"
"strconv"
"strings"
"unicode"
"github.com/google/go-cmp/cmp/internal/flags"
"github.com/google/go-cmp/cmp/internal/value"
)
type formatValueOptions struct {
// AvoidStringer controls whether to avoid calling custom stringer
// methods like error.Error or fmt.Stringer.String.
AvoidStringer bool
// ShallowPointers controls whether to avoid descending into pointers.
// Useful when printing map keys, where pointer comparison is performed
// on the pointer address rather than the pointed-at value.
ShallowPointers bool
// PrintAddresses controls whether to print the address of all pointers,
// slice elements, and maps.
PrintAddresses bool
}
// FormatType prints the type as if it were wrapping s.
// This may return s as-is depending on the current type and TypeMode mode.
func (opts formatOptions) FormatType(t reflect.Type, s textNode) textNode {
// Check whether to emit the type or not.
switch opts.TypeMode {
case autoType:
switch t.Kind() {
case reflect.Struct, reflect.Slice, reflect.Array, reflect.Map:
if s.Equal(textNil) {
return s
}
default:
return s
}
case elideType:
return s
}
// Determine the type label, applying special handling for unnamed types.
typeName := t.String()
if t.Name() == "" {
// According to Go grammar, certain type literals contain symbols that
// do not strongly bind to the next lexicographical token (e.g., *T).
switch t.Kind() {
case reflect.Chan, reflect.Func, reflect.Ptr:
typeName = "(" + typeName + ")"
}
typeName = strings.Replace(typeName, "struct {", "struct{", -1)
typeName = strings.Replace(typeName, "interface {", "interface{", -1)
}
// Avoid wrap the value in parenthesis if unnecessary.
if s, ok := s.(textWrap); ok {
hasParens := strings.HasPrefix(s.Prefix, "(") && strings.HasSuffix(s.Suffix, ")")
hasBraces := strings.HasPrefix(s.Prefix, "{") && strings.HasSuffix(s.Suffix, "}")
if hasParens || hasBraces {
return textWrap{typeName, s, ""}
}
}
return textWrap{typeName + "(", s, ")"}
}
// FormatValue prints the reflect.Value, taking extra care to avoid descending
// into pointers already in m. As pointers are visited, m is also updated.
func (opts formatOptions) FormatValue(v reflect.Value, withinSlice bool, m visitedPointers) (out textNode) {
if !v.IsValid() {
return nil
}
t := v.Type()
// Check whether there is an Error or String method to call.
if !opts.AvoidStringer && v.CanInterface() {
// Avoid calling Error or String methods on nil receivers since many
// implementations crash when doing so.
if (t.Kind() != reflect.Ptr && t.Kind() != reflect.Interface) || !v.IsNil() {
switch v := v.Interface().(type) {
case error:
return textLine("e" + formatString(v.Error()))
case fmt.Stringer:
return textLine("s" + formatString(v.String()))
}
}
}
// Check whether to explicitly wrap the result with the type.
var skipType bool
defer func() {
if !skipType {
out = opts.FormatType(t, out)
}
}()
var ptr string
switch t.Kind() {
case reflect.Bool:
return textLine(fmt.Sprint(v.Bool()))
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return textLine(fmt.Sprint(v.Int()))
case reflect.Uint, reflect.Uint16, reflect.Uint32, reflect.Uint64:
return textLine(fmt.Sprint(v.Uint()))
case reflect.Uint8:
if withinSlice {
return textLine(formatHex(v.Uint()))
}
return textLine(fmt.Sprint(v.Uint()))
case reflect.Uintptr:
return textLine(formatHex(v.Uint()))
case reflect.Float32, reflect.Float64:
return textLine(fmt.Sprint(v.Float()))
case reflect.Complex64, reflect.Complex128:
return textLine(fmt.Sprint(v.Complex()))
case reflect.String:
return textLine(formatString(v.String()))
case reflect.UnsafePointer, reflect.Chan, reflect.Func:
return textLine(formatPointer(v))
case reflect.Struct:
var list textList
for i := 0; i < v.NumField(); i++ {
vv := v.Field(i)
if value.IsZero(vv) {
continue // Elide fields with zero values
}
s := opts.WithTypeMode(autoType).FormatValue(vv, false, m)
list = append(list, textRecord{Key: t.Field(i).Name, Value: s})
}
return textWrap{"{", list, "}"}
case reflect.Slice:
if v.IsNil() {
return textNil
}
if opts.PrintAddresses {
ptr = formatPointer(v)
}
fallthrough
case reflect.Array:
var list textList
for i := 0; i < v.Len(); i++ {
vi := v.Index(i)
if vi.CanAddr() { // Check for cyclic elements
p := vi.Addr()
if m.Visit(p) {
var out textNode
out = textLine(formatPointer(p))
out = opts.WithTypeMode(emitType).FormatType(p.Type(), out)
out = textWrap{"*", out, ""}
list = append(list, textRecord{Value: out})
continue
}
}
s := opts.WithTypeMode(elideType).FormatValue(vi, true, m)
list = append(list, textRecord{Value: s})
}
return textWrap{ptr + "{", list, "}"}
case reflect.Map:
if v.IsNil() {
return textNil
}
if m.Visit(v) {
return textLine(formatPointer(v))
}
var list textList
for _, k := range value.SortKeys(v.MapKeys()) {
sk := formatMapKey(k)
sv := opts.WithTypeMode(elideType).FormatValue(v.MapIndex(k), false, m)
list = append(list, textRecord{Key: sk, Value: sv})
}
if opts.PrintAddresses {
ptr = formatPointer(v)
}
return textWrap{ptr + "{", list, "}"}
case reflect.Ptr:
if v.IsNil() {
return textNil
}
if m.Visit(v) || opts.ShallowPointers {
return textLine(formatPointer(v))
}
if opts.PrintAddresses {
ptr = formatPointer(v)
}
skipType = true // Let the underlying value print the type instead
return textWrap{"&" + ptr, opts.FormatValue(v.Elem(), false, m), ""}
case reflect.Interface:
if v.IsNil() {
return textNil
}
// Interfaces accept different concrete types,
// so configure the underlying value to explicitly print the type.
skipType = true // Print the concrete type instead
return opts.WithTypeMode(emitType).FormatValue(v.Elem(), false, m)
default:
panic(fmt.Sprintf("%v kind not handled", v.Kind()))
}
}
// formatMapKey formats v as if it were a map key.
// The result is guaranteed to be a single line.
func formatMapKey(v reflect.Value) string {
var opts formatOptions
opts.TypeMode = elideType
opts.ShallowPointers = true
s := opts.FormatValue(v, false, visitedPointers{}).String()
return strings.TrimSpace(s)
}
// formatString prints s as a double-quoted or backtick-quoted string.
func formatString(s string) string {
// Use quoted string if it the same length as a raw string literal.
// Otherwise, attempt to use the raw string form.
qs := strconv.Quote(s)
if len(qs) == 1+len(s)+1 {
return qs
}
// Disallow newlines to ensure output is a single line.
// Only allow printable runes for readability purposes.
rawInvalid := func(r rune) bool {
return r == '`' || r == '\n' || !(unicode.IsPrint(r) || r == '\t')
}
if strings.IndexFunc(s, rawInvalid) < 0 {
return "`" + s + "`"
}
return qs
}
// formatHex prints u as a hexadecimal integer in Go notation.
func formatHex(u uint64) string {
var f string
switch {
case u <= 0xff:
f = "0x%02x"
case u <= 0xffff:
f = "0x%04x"
case u <= 0xffffff:
f = "0x%06x"
case u <= 0xffffffff:
f = "0x%08x"
case u <= 0xffffffffff:
f = "0x%010x"
case u <= 0xffffffffffff:
f = "0x%012x"
case u <= 0xffffffffffffff:
f = "0x%014x"
case u <= 0xffffffffffffffff:
f = "0x%016x"
}
return fmt.Sprintf(f, u)
}
// formatPointer prints the address of the pointer.
func formatPointer(v reflect.Value) string {
p := v.Pointer()
if flags.Deterministic {
p = 0xdeadf00f // Only used for stable testing purposes
}
return fmt.Sprintf("⟪0x%x⟫", p)
}
type visitedPointers map[value.Pointer]struct{}
// Visit inserts pointer v into the visited map and reports whether it had
// already been visited before.
func (m visitedPointers) Visit(v reflect.Value) bool {
p := value.PointerOf(v)
_, visited := m[p]
m[p] = struct{}{}
return visited
}

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vendor/github.com/google/go-cmp/cmp/report_slices.go generated vendored Normal file
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// Copyright 2019, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
package cmp
import (
"bytes"
"fmt"
"reflect"
"strings"
"unicode"
"unicode/utf8"
"github.com/google/go-cmp/cmp/internal/diff"
)
// CanFormatDiffSlice reports whether we support custom formatting for nodes
// that are slices of primitive kinds or strings.
func (opts formatOptions) CanFormatDiffSlice(v *valueNode) bool {
switch {
case opts.DiffMode != diffUnknown:
return false // Must be formatting in diff mode
case v.NumDiff == 0:
return false // No differences detected
case v.NumIgnored+v.NumCompared+v.NumTransformed > 0:
// TODO: Handle the case where someone uses bytes.Equal on a large slice.
return false // Some custom option was used to determined equality
case !v.ValueX.IsValid() || !v.ValueY.IsValid():
return false // Both values must be valid
}
switch t := v.Type; t.Kind() {
case reflect.String:
case reflect.Array, reflect.Slice:
// Only slices of primitive types have specialized handling.
switch t.Elem().Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr,
reflect.Bool, reflect.Float32, reflect.Float64, reflect.Complex64, reflect.Complex128:
default:
return false
}
// If a sufficient number of elements already differ,
// use specialized formatting even if length requirement is not met.
if v.NumDiff > v.NumSame {
return true
}
default:
return false
}
// Use specialized string diffing for longer slices or strings.
const minLength = 64
return v.ValueX.Len() >= minLength && v.ValueY.Len() >= minLength
}
// FormatDiffSlice prints a diff for the slices (or strings) represented by v.
// This provides custom-tailored logic to make printing of differences in
// textual strings and slices of primitive kinds more readable.
func (opts formatOptions) FormatDiffSlice(v *valueNode) textNode {
assert(opts.DiffMode == diffUnknown)
t, vx, vy := v.Type, v.ValueX, v.ValueY
// Auto-detect the type of the data.
var isLinedText, isText, isBinary bool
var sx, sy string
switch {
case t.Kind() == reflect.String:
sx, sy = vx.String(), vy.String()
isText = true // Initial estimate, verify later
case t.Kind() == reflect.Slice && t.Elem() == reflect.TypeOf(byte(0)):
sx, sy = string(vx.Bytes()), string(vy.Bytes())
isBinary = true // Initial estimate, verify later
case t.Kind() == reflect.Array:
// Arrays need to be addressable for slice operations to work.
vx2, vy2 := reflect.New(t).Elem(), reflect.New(t).Elem()
vx2.Set(vx)
vy2.Set(vy)
vx, vy = vx2, vy2
}
if isText || isBinary {
var numLines, lastLineIdx, maxLineLen int
isBinary = false
for i, r := range sx + sy {
if !(unicode.IsPrint(r) || unicode.IsSpace(r)) || r == utf8.RuneError {
isBinary = true
break
}
if r == '\n' {
if maxLineLen < i-lastLineIdx {
maxLineLen = i - lastLineIdx
}
lastLineIdx = i + 1
numLines++
}
}
isText = !isBinary
isLinedText = isText && numLines >= 4 && maxLineLen <= 256
}
// Format the string into printable records.
var list textList
var delim string
switch {
// If the text appears to be multi-lined text,
// then perform differencing across individual lines.
case isLinedText:
ssx := strings.Split(sx, "\n")
ssy := strings.Split(sy, "\n")
list = opts.formatDiffSlice(
reflect.ValueOf(ssx), reflect.ValueOf(ssy), 1, "line",
func(v reflect.Value, d diffMode) textRecord {
s := formatString(v.Index(0).String())
return textRecord{Diff: d, Value: textLine(s)}
},
)
delim = "\n"
// If the text appears to be single-lined text,
// then perform differencing in approximately fixed-sized chunks.
// The output is printed as quoted strings.
case isText:
list = opts.formatDiffSlice(
reflect.ValueOf(sx), reflect.ValueOf(sy), 64, "byte",
func(v reflect.Value, d diffMode) textRecord {
s := formatString(v.String())
return textRecord{Diff: d, Value: textLine(s)}
},
)
delim = ""
// If the text appears to be binary data,
// then perform differencing in approximately fixed-sized chunks.
// The output is inspired by hexdump.
case isBinary:
list = opts.formatDiffSlice(
reflect.ValueOf(sx), reflect.ValueOf(sy), 16, "byte",
func(v reflect.Value, d diffMode) textRecord {
var ss []string
for i := 0; i < v.Len(); i++ {
ss = append(ss, formatHex(v.Index(i).Uint()))
}
s := strings.Join(ss, ", ")
comment := commentString(fmt.Sprintf("%c|%v|", d, formatASCII(v.String())))
return textRecord{Diff: d, Value: textLine(s), Comment: comment}
},
)
// For all other slices of primitive types,
// then perform differencing in approximately fixed-sized chunks.
// The size of each chunk depends on the width of the element kind.
default:
var chunkSize int
if t.Elem().Kind() == reflect.Bool {
chunkSize = 16
} else {
switch t.Elem().Bits() {
case 8:
chunkSize = 16
case 16:
chunkSize = 12
case 32:
chunkSize = 8
default:
chunkSize = 8
}
}
list = opts.formatDiffSlice(
vx, vy, chunkSize, t.Elem().Kind().String(),
func(v reflect.Value, d diffMode) textRecord {
var ss []string
for i := 0; i < v.Len(); i++ {
switch t.Elem().Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
ss = append(ss, fmt.Sprint(v.Index(i).Int()))
case reflect.Uint, reflect.Uint16, reflect.Uint32, reflect.Uint64:
ss = append(ss, fmt.Sprint(v.Index(i).Uint()))
case reflect.Uint8, reflect.Uintptr:
ss = append(ss, formatHex(v.Index(i).Uint()))
case reflect.Bool, reflect.Float32, reflect.Float64, reflect.Complex64, reflect.Complex128:
ss = append(ss, fmt.Sprint(v.Index(i).Interface()))
}
}
s := strings.Join(ss, ", ")
return textRecord{Diff: d, Value: textLine(s)}
},
)
}
// Wrap the output with appropriate type information.
var out textNode = textWrap{"{", list, "}"}
if !isText {
// The "{...}" byte-sequence literal is not valid Go syntax for strings.
// Emit the type for extra clarity (e.g. "string{...}").
if t.Kind() == reflect.String {
opts = opts.WithTypeMode(emitType)
}
return opts.FormatType(t, out)
}
switch t.Kind() {
case reflect.String:
out = textWrap{"strings.Join(", out, fmt.Sprintf(", %q)", delim)}
if t != reflect.TypeOf(string("")) {
out = opts.FormatType(t, out)
}
case reflect.Slice:
out = textWrap{"bytes.Join(", out, fmt.Sprintf(", %q)", delim)}
if t != reflect.TypeOf([]byte(nil)) {
out = opts.FormatType(t, out)
}
}
return out
}
// formatASCII formats s as an ASCII string.
// This is useful for printing binary strings in a semi-legible way.
func formatASCII(s string) string {
b := bytes.Repeat([]byte{'.'}, len(s))
for i := 0; i < len(s); i++ {
if ' ' <= s[i] && s[i] <= '~' {
b[i] = s[i]
}
}
return string(b)
}
func (opts formatOptions) formatDiffSlice(
vx, vy reflect.Value, chunkSize int, name string,
makeRec func(reflect.Value, diffMode) textRecord,
) (list textList) {
es := diff.Difference(vx.Len(), vy.Len(), func(ix int, iy int) diff.Result {
return diff.BoolResult(vx.Index(ix).Interface() == vy.Index(iy).Interface())
})
appendChunks := func(v reflect.Value, d diffMode) int {
n0 := v.Len()
for v.Len() > 0 {
n := chunkSize
if n > v.Len() {
n = v.Len()
}
list = append(list, makeRec(v.Slice(0, n), d))
v = v.Slice(n, v.Len())
}
return n0 - v.Len()
}
groups := coalesceAdjacentEdits(name, es)
groups = coalesceInterveningIdentical(groups, chunkSize/4)
for i, ds := range groups {
// Print equal.
if ds.NumDiff() == 0 {
// Compute the number of leading and trailing equal bytes to print.
var numLo, numHi int
numEqual := ds.NumIgnored + ds.NumIdentical
for numLo < chunkSize*numContextRecords && numLo+numHi < numEqual && i != 0 {
numLo++
}
for numHi < chunkSize*numContextRecords && numLo+numHi < numEqual && i != len(groups)-1 {
numHi++
}
if numEqual-(numLo+numHi) <= chunkSize && ds.NumIgnored == 0 {
numHi = numEqual - numLo // Avoid pointless coalescing of single equal row
}
// Print the equal bytes.
appendChunks(vx.Slice(0, numLo), diffIdentical)
if numEqual > numLo+numHi {
ds.NumIdentical -= numLo + numHi
list.AppendEllipsis(ds)
}
appendChunks(vx.Slice(numEqual-numHi, numEqual), diffIdentical)
vx = vx.Slice(numEqual, vx.Len())
vy = vy.Slice(numEqual, vy.Len())
continue
}
// Print unequal.
nx := appendChunks(vx.Slice(0, ds.NumIdentical+ds.NumRemoved+ds.NumModified), diffRemoved)
vx = vx.Slice(nx, vx.Len())
ny := appendChunks(vy.Slice(0, ds.NumIdentical+ds.NumInserted+ds.NumModified), diffInserted)
vy = vy.Slice(ny, vy.Len())
}
assert(vx.Len() == 0 && vy.Len() == 0)
return list
}
// coalesceAdjacentEdits coalesces the list of edits into groups of adjacent
// equal or unequal counts.
func coalesceAdjacentEdits(name string, es diff.EditScript) (groups []diffStats) {
var prevCase int // Arbitrary index into which case last occurred
lastStats := func(i int) *diffStats {
if prevCase != i {
groups = append(groups, diffStats{Name: name})
prevCase = i
}
return &groups[len(groups)-1]
}
for _, e := range es {
switch e {
case diff.Identity:
lastStats(1).NumIdentical++
case diff.UniqueX:
lastStats(2).NumRemoved++
case diff.UniqueY:
lastStats(2).NumInserted++
case diff.Modified:
lastStats(2).NumModified++
}
}
return groups
}
// coalesceInterveningIdentical coalesces sufficiently short (<= windowSize)
// equal groups into adjacent unequal groups that currently result in a
// dual inserted/removed printout. This acts as a high-pass filter to smooth
// out high-frequency changes within the windowSize.
func coalesceInterveningIdentical(groups []diffStats, windowSize int) []diffStats {
groups, groupsOrig := groups[:0], groups
for i, ds := range groupsOrig {
if len(groups) >= 2 && ds.NumDiff() > 0 {
prev := &groups[len(groups)-2] // Unequal group
curr := &groups[len(groups)-1] // Equal group
next := &groupsOrig[i] // Unequal group
hadX, hadY := prev.NumRemoved > 0, prev.NumInserted > 0
hasX, hasY := next.NumRemoved > 0, next.NumInserted > 0
if ((hadX || hasX) && (hadY || hasY)) && curr.NumIdentical <= windowSize {
*prev = prev.Append(*curr).Append(*next)
groups = groups[:len(groups)-1] // Truncate off equal group
continue
}
}
groups = append(groups, ds)
}
return groups
}

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vendor/github.com/google/go-cmp/cmp/report_text.go generated vendored Normal file
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// Copyright 2019, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
package cmp
import (
"bytes"
"fmt"
"math/rand"
"strings"
"time"
"github.com/google/go-cmp/cmp/internal/flags"
)
var randBool = rand.New(rand.NewSource(time.Now().Unix())).Intn(2) == 0
type indentMode int
func (n indentMode) appendIndent(b []byte, d diffMode) []byte {
// The output of Diff is documented as being unstable to provide future
// flexibility in changing the output for more humanly readable reports.
// This logic intentionally introduces instability to the exact output
// so that users can detect accidental reliance on stability early on,
// rather than much later when an actual change to the format occurs.
if flags.Deterministic || randBool {
// Use regular spaces (U+0020).
switch d {
case diffUnknown, diffIdentical:
b = append(b, " "...)
case diffRemoved:
b = append(b, "- "...)
case diffInserted:
b = append(b, "+ "...)
}
} else {
// Use non-breaking spaces (U+00a0).
switch d {
case diffUnknown, diffIdentical:
b = append(b, "  "...)
case diffRemoved:
b = append(b, "- "...)
case diffInserted:
b = append(b, "+ "...)
}
}
return repeatCount(n).appendChar(b, '\t')
}
type repeatCount int
func (n repeatCount) appendChar(b []byte, c byte) []byte {
for ; n > 0; n-- {
b = append(b, c)
}
return b
}
// textNode is a simplified tree-based representation of structured text.
// Possible node types are textWrap, textList, or textLine.
type textNode interface {
// Len reports the length in bytes of a single-line version of the tree.
// Nested textRecord.Diff and textRecord.Comment fields are ignored.
Len() int
// Equal reports whether the two trees are structurally identical.
// Nested textRecord.Diff and textRecord.Comment fields are compared.
Equal(textNode) bool
// String returns the string representation of the text tree.
// It is not guaranteed that len(x.String()) == x.Len(),
// nor that x.String() == y.String() implies that x.Equal(y).
String() string
// formatCompactTo formats the contents of the tree as a single-line string
// to the provided buffer. Any nested textRecord.Diff and textRecord.Comment
// fields are ignored.
//
// However, not all nodes in the tree should be collapsed as a single-line.
// If a node can be collapsed as a single-line, it is replaced by a textLine
// node. Since the top-level node cannot replace itself, this also returns
// the current node itself.
//
// This does not mutate the receiver.
formatCompactTo([]byte, diffMode) ([]byte, textNode)
// formatExpandedTo formats the contents of the tree as a multi-line string
// to the provided buffer. In order for column alignment to operate well,
// formatCompactTo must be called before calling formatExpandedTo.
formatExpandedTo([]byte, diffMode, indentMode) []byte
}
// textWrap is a wrapper that concatenates a prefix and/or a suffix
// to the underlying node.
type textWrap struct {
Prefix string // e.g., "bytes.Buffer{"
Value textNode // textWrap | textList | textLine
Suffix string // e.g., "}"
}
func (s textWrap) Len() int {
return len(s.Prefix) + s.Value.Len() + len(s.Suffix)
}
func (s1 textWrap) Equal(s2 textNode) bool {
if s2, ok := s2.(textWrap); ok {
return s1.Prefix == s2.Prefix && s1.Value.Equal(s2.Value) && s1.Suffix == s2.Suffix
}
return false
}
func (s textWrap) String() string {
var d diffMode
var n indentMode
_, s2 := s.formatCompactTo(nil, d)
b := n.appendIndent(nil, d) // Leading indent
b = s2.formatExpandedTo(b, d, n) // Main body
b = append(b, '\n') // Trailing newline
return string(b)
}
func (s textWrap) formatCompactTo(b []byte, d diffMode) ([]byte, textNode) {
n0 := len(b) // Original buffer length
b = append(b, s.Prefix...)
b, s.Value = s.Value.formatCompactTo(b, d)
b = append(b, s.Suffix...)
if _, ok := s.Value.(textLine); ok {
return b, textLine(b[n0:])
}
return b, s
}
func (s textWrap) formatExpandedTo(b []byte, d diffMode, n indentMode) []byte {
b = append(b, s.Prefix...)
b = s.Value.formatExpandedTo(b, d, n)
b = append(b, s.Suffix...)
return b
}
// textList is a comma-separated list of textWrap or textLine nodes.
// The list may be formatted as multi-lines or single-line at the discretion
// of the textList.formatCompactTo method.
type textList []textRecord
type textRecord struct {
Diff diffMode // e.g., 0 or '-' or '+'
Key string // e.g., "MyField"
Value textNode // textWrap | textLine
Comment fmt.Stringer // e.g., "6 identical fields"
}
// AppendEllipsis appends a new ellipsis node to the list if none already
// exists at the end. If cs is non-zero it coalesces the statistics with the
// previous diffStats.
func (s *textList) AppendEllipsis(ds diffStats) {
hasStats := ds != diffStats{}
if len(*s) == 0 || !(*s)[len(*s)-1].Value.Equal(textEllipsis) {
if hasStats {
*s = append(*s, textRecord{Value: textEllipsis, Comment: ds})
} else {
*s = append(*s, textRecord{Value: textEllipsis})
}
return
}
if hasStats {
(*s)[len(*s)-1].Comment = (*s)[len(*s)-1].Comment.(diffStats).Append(ds)
}
}
func (s textList) Len() (n int) {
for i, r := range s {
n += len(r.Key)
if r.Key != "" {
n += len(": ")
}
n += r.Value.Len()
if i < len(s)-1 {
n += len(", ")
}
}
return n
}
func (s1 textList) Equal(s2 textNode) bool {
if s2, ok := s2.(textList); ok {
if len(s1) != len(s2) {
return false
}
for i := range s1 {
r1, r2 := s1[i], s2[i]
if !(r1.Diff == r2.Diff && r1.Key == r2.Key && r1.Value.Equal(r2.Value) && r1.Comment == r2.Comment) {
return false
}
}
return true
}
return false
}
func (s textList) String() string {
return textWrap{"{", s, "}"}.String()
}
func (s textList) formatCompactTo(b []byte, d diffMode) ([]byte, textNode) {
s = append(textList(nil), s...) // Avoid mutating original
// Determine whether we can collapse this list as a single line.
n0 := len(b) // Original buffer length
var multiLine bool
for i, r := range s {
if r.Diff == diffInserted || r.Diff == diffRemoved {
multiLine = true
}
b = append(b, r.Key...)
if r.Key != "" {
b = append(b, ": "...)
}
b, s[i].Value = r.Value.formatCompactTo(b, d|r.Diff)
if _, ok := s[i].Value.(textLine); !ok {
multiLine = true
}
if r.Comment != nil {
multiLine = true
}
if i < len(s)-1 {
b = append(b, ", "...)
}
}
// Force multi-lined output when printing a removed/inserted node that
// is sufficiently long.
if (d == diffInserted || d == diffRemoved) && len(b[n0:]) > 80 {
multiLine = true
}
if !multiLine {
return b, textLine(b[n0:])
}
return b, s
}
func (s textList) formatExpandedTo(b []byte, d diffMode, n indentMode) []byte {
alignKeyLens := s.alignLens(
func(r textRecord) bool {
_, isLine := r.Value.(textLine)
return r.Key == "" || !isLine
},
func(r textRecord) int { return len(r.Key) },
)
alignValueLens := s.alignLens(
func(r textRecord) bool {
_, isLine := r.Value.(textLine)
return !isLine || r.Value.Equal(textEllipsis) || r.Comment == nil
},
func(r textRecord) int { return len(r.Value.(textLine)) },
)
// Format the list as a multi-lined output.
n++
for i, r := range s {
b = n.appendIndent(append(b, '\n'), d|r.Diff)
if r.Key != "" {
b = append(b, r.Key+": "...)
}
b = alignKeyLens[i].appendChar(b, ' ')
b = r.Value.formatExpandedTo(b, d|r.Diff, n)
if !r.Value.Equal(textEllipsis) {
b = append(b, ',')
}
b = alignValueLens[i].appendChar(b, ' ')
if r.Comment != nil {
b = append(b, " // "+r.Comment.String()...)
}
}
n--
return n.appendIndent(append(b, '\n'), d)
}
func (s textList) alignLens(
skipFunc func(textRecord) bool,
lenFunc func(textRecord) int,
) []repeatCount {
var startIdx, endIdx, maxLen int
lens := make([]repeatCount, len(s))
for i, r := range s {
if skipFunc(r) {
for j := startIdx; j < endIdx && j < len(s); j++ {
lens[j] = repeatCount(maxLen - lenFunc(s[j]))
}
startIdx, endIdx, maxLen = i+1, i+1, 0
} else {
if maxLen < lenFunc(r) {
maxLen = lenFunc(r)
}
endIdx = i + 1
}
}
for j := startIdx; j < endIdx && j < len(s); j++ {
lens[j] = repeatCount(maxLen - lenFunc(s[j]))
}
return lens
}
// textLine is a single-line segment of text and is always a leaf node
// in the textNode tree.
type textLine []byte
var (
textNil = textLine("nil")
textEllipsis = textLine("...")
)
func (s textLine) Len() int {
return len(s)
}
func (s1 textLine) Equal(s2 textNode) bool {
if s2, ok := s2.(textLine); ok {
return bytes.Equal([]byte(s1), []byte(s2))
}
return false
}
func (s textLine) String() string {
return string(s)
}
func (s textLine) formatCompactTo(b []byte, d diffMode) ([]byte, textNode) {
return append(b, s...), s
}
func (s textLine) formatExpandedTo(b []byte, _ diffMode, _ indentMode) []byte {
return append(b, s...)
}
type diffStats struct {
Name string
NumIgnored int
NumIdentical int
NumRemoved int
NumInserted int
NumModified int
}
func (s diffStats) NumDiff() int {
return s.NumRemoved + s.NumInserted + s.NumModified
}
func (s diffStats) Append(ds diffStats) diffStats {
assert(s.Name == ds.Name)
s.NumIgnored += ds.NumIgnored
s.NumIdentical += ds.NumIdentical
s.NumRemoved += ds.NumRemoved
s.NumInserted += ds.NumInserted
s.NumModified += ds.NumModified
return s
}
// String prints a humanly-readable summary of coalesced records.
//
// Example:
// diffStats{Name: "Field", NumIgnored: 5}.String() => "5 ignored fields"
func (s diffStats) String() string {
var ss []string
var sum int
labels := [...]string{"ignored", "identical", "removed", "inserted", "modified"}
counts := [...]int{s.NumIgnored, s.NumIdentical, s.NumRemoved, s.NumInserted, s.NumModified}
for i, n := range counts {
if n > 0 {
ss = append(ss, fmt.Sprintf("%d %v", n, labels[i]))
}
sum += n
}
// Pluralize the name (adjusting for some obscure English grammar rules).
name := s.Name
if sum > 1 {
name += "s"
if strings.HasSuffix(name, "ys") {
name = name[:len(name)-2] + "ies" // e.g., "entrys" => "entries"
}
}
// Format the list according to English grammar (with Oxford comma).
switch n := len(ss); n {
case 0:
return ""
case 1, 2:
return strings.Join(ss, " and ") + " " + name
default:
return strings.Join(ss[:n-1], ", ") + ", and " + ss[n-1] + " " + name
}
}
type commentString string
func (s commentString) String() string { return string(s) }

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// Copyright 2019, The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE.md file.
package cmp
import "reflect"
// valueNode represents a single node within a report, which is a
// structured representation of the value tree, containing information
// regarding which nodes are equal or not.
type valueNode struct {
parent *valueNode
Type reflect.Type
ValueX reflect.Value
ValueY reflect.Value
// NumSame is the number of leaf nodes that are equal.
// All descendants are equal only if NumDiff is 0.
NumSame int
// NumDiff is the number of leaf nodes that are not equal.
NumDiff int
// NumIgnored is the number of leaf nodes that are ignored.
NumIgnored int
// NumCompared is the number of leaf nodes that were compared
// using an Equal method or Comparer function.
NumCompared int
// NumTransformed is the number of non-leaf nodes that were transformed.
NumTransformed int
// NumChildren is the number of transitive descendants of this node.
// This counts from zero; thus, leaf nodes have no descendants.
NumChildren int
// MaxDepth is the maximum depth of the tree. This counts from zero;
// thus, leaf nodes have a depth of zero.
MaxDepth int
// Records is a list of struct fields, slice elements, or map entries.
Records []reportRecord // If populated, implies Value is not populated
// Value is the result of a transformation, pointer indirect, of
// type assertion.
Value *valueNode // If populated, implies Records is not populated
// TransformerName is the name of the transformer.
TransformerName string // If non-empty, implies Value is populated
}
type reportRecord struct {
Key reflect.Value // Invalid for slice element
Value *valueNode
}
func (parent *valueNode) PushStep(ps PathStep) (child *valueNode) {
vx, vy := ps.Values()
child = &valueNode{parent: parent, Type: ps.Type(), ValueX: vx, ValueY: vy}
switch s := ps.(type) {
case StructField:
assert(parent.Value == nil)
parent.Records = append(parent.Records, reportRecord{Key: reflect.ValueOf(s.Name()), Value: child})
case SliceIndex:
assert(parent.Value == nil)
parent.Records = append(parent.Records, reportRecord{Value: child})
case MapIndex:
assert(parent.Value == nil)
parent.Records = append(parent.Records, reportRecord{Key: s.Key(), Value: child})
case Indirect:
assert(parent.Value == nil && parent.Records == nil)
parent.Value = child
case TypeAssertion:
assert(parent.Value == nil && parent.Records == nil)
parent.Value = child
case Transform:
assert(parent.Value == nil && parent.Records == nil)
parent.Value = child
parent.TransformerName = s.Name()
parent.NumTransformed++
default:
assert(parent == nil) // Must be the root step
}
return child
}
func (r *valueNode) Report(rs Result) {
assert(r.MaxDepth == 0) // May only be called on leaf nodes
if rs.ByIgnore() {
r.NumIgnored++
} else {
if rs.Equal() {
r.NumSame++
} else {
r.NumDiff++
}
}
assert(r.NumSame+r.NumDiff+r.NumIgnored == 1)
if rs.ByMethod() {
r.NumCompared++
}
if rs.ByFunc() {
r.NumCompared++
}
assert(r.NumCompared <= 1)
}
func (child *valueNode) PopStep() (parent *valueNode) {
if child.parent == nil {
return nil
}
parent = child.parent
parent.NumSame += child.NumSame
parent.NumDiff += child.NumDiff
parent.NumIgnored += child.NumIgnored
parent.NumCompared += child.NumCompared
parent.NumTransformed += child.NumTransformed
parent.NumChildren += child.NumChildren + 1
if parent.MaxDepth < child.MaxDepth+1 {
parent.MaxDepth = child.MaxDepth + 1
}
return parent
}

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# github.com/google/go-cmp v0.4.1
## explicit
github.com/google/go-cmp/cmp
github.com/google/go-cmp/cmp/internal/diff
github.com/google/go-cmp/cmp/internal/flags
github.com/google/go-cmp/cmp/internal/function
github.com/google/go-cmp/cmp/internal/value