more fuzzed fixes

main.go

@@ -14,6 +14,8 @@ import (
 	"golang.org/x/term"
 )
 
+const DEBUG = false
+
 var (
 	// upper-left, upper-right, left side, right side, bottom-left, bottom-right
 	SAY_BORDER    = []rune{'/', '\\', '|', '|', '\\', '/'}
@@ -103,7 +105,7 @@ func main() {
 		if err != nil {
 			log.Fatalf("error reading from stdin: %v", err)
 		}
-		input = strings.TrimSpace(string(pipedInput))
+		input = string(bytes.TrimSpace(pipedInput))
 	}
 
 	if input == "" {
@@ -115,7 +117,7 @@ func main() {
 		log.Fatal(err)
 	}
 
-	generateCow(string(b), input, opts)
+	fmt.Print(generateCow(string(b), input, opts))
 }
 
 func generateCow(cow, say string, opt options) string {
@@ -157,21 +159,73 @@ func generateCow(cow, say string, opt options) string {
 	return out.String()
 }
 
+// this is an attempt to emulate the rather poorly-documented behavior of Text::Wrap::fill
+// from CPAN: https://github.com/ap/Text-Tabs/blob/master/lib.modern/Text/Wrap.pm
+// The basic idea is: take an input. Format each "paragraph" of text independently,
+// then merge with empty lines between.
+//
+// What is under-defined in the documentation is what fill() considers a "paragraph".
+// From testing and reviewing the rather obtuse code, a paragraph is any number of lines
+// that start with a line that has optional whitespace at its start, then all subsequent lines
+// that have no whitespace at the start, until either reaching another line that has leading
+// whitespace, or a blank line. fill() also "destroy[s] any whitespace in the original text",
+// by which it appearently means all tabs and multiple-spaces are replaced with single-spaces.
+//
+// So, for example, `text\ntext` is one paragraph, `text\n text` is two paragraphs. Since for
+// our purposes we don't want any indentation of paragraphs, the output of these two examples
+// should be `text text` and `text\n\ntext`, respectively.
+//
+// This is a pretty gnarly! Might be easier in a multi-pass model: collect together each paragraph,
+// collapse them into single strings and format in a sub-function, then merge them all together.
+// That's closer to how the perl module does it.
 func wordWrap(text []string, column int) ([]string, int) {
 	out := []string{}
 	length := 0
 	var b strings.Builder
-	for _, line := range text {
-		b = strings.Builder{}
+	var inParagraph bool
+	for beginning, line := range text {
 		// remove control character whitespace
 		line = strings.ReplaceAll(line, "\t", " ")
 		line = strings.ReplaceAll(line, "\v", " ")
 		line = strings.ReplaceAll(line, "\f", " ")
+		line = strings.ReplaceAll(line, "\r", " ")
 		words := strings.Split(line, " ")
+		// skip empty newlines if not in a paragraph, but start a new paragraph if we are.
+		if strings.TrimSpace(line) == "" {
+			if inParagraph {
+				length = max(length, b.Len()-1)
+				out = append(out, b.String()[0:b.Len()-1])
+				out = append(out, "")
+				b = strings.Builder{}
+				inParagraph = false
+			}
+			continue
+		}
 		// we -1 all over the place to clean up the loose space on the end of the builder
-		for _, word := range words { // split into words
-			if b.Len() > 0 && word == "" {
-				// skip multiple spaces in a row
+		for i, word := range words { // split into words
+			if DEBUG {
+				log.Printf("%d, `%s`", i, b.String())
+			}
+			if inParagraph && i == 0 && word == "" && len(words) != 0 {
+				// we've found a new paragraph while we were still processing the old one.
+				// (that is, the new line we're parsing had leading whitespace)
+				length = max(length, b.Len()-1)
+				out = append(out, b.String()[0:b.Len()-1])
+				out = append(out, "")
+				b = strings.Builder{}
+				log.Println("here")
+			}
+			// bizarrely, cowsay allows for indentation to survive in the /first/ paragraph,
+			// but only up to two spaces worth.
+			if beginning == 0 && (b.Len() == 0 || b.String() == " ") && word == "" {
+				b.WriteRune(' ')
+			}
+			if b.Len() == 0 && word != "" {
+				inParagraph = true
+			}
+			if b.Len() >= 0 && word == "" && i+1 != len(words) {
+				// skip multiple spaces in a row...
+				// ...but a single trailing space on a line is OK??
 				continue
 			}
 			if b.Len() > 0 && b.Len()+len(word)+1 > column {
@@ -182,8 +236,9 @@ func wordWrap(text []string, column int) ([]string, int) {
 				out = append(out, b.String()[0:b.Len()-1])
 				b = strings.Builder{}
 			}
-			if b.Len() == 0 && len(word) >= column {
+			for b.Len() == 0 && len(word) >= column {
 				// our word is longer than our maximum column size. let's break it up.
+				// we loop until we've consumed the full overly-long word.
 				length = max(length, column-1)
 				out = append(out, word[0:column-1])
 				word = word[column-1:]
@@ -192,11 +247,14 @@ func wordWrap(text []string, column int) ([]string, int) {
 			// actually append the word and a space
 			b.WriteString(word)
 			b.WriteRune(' ')
+			if DEBUG {
+				log.Printf("%d, `%s`", i, b.String())
+			}
 		}
-		// out of words in the line, so save it off and start on the next one
-		length = max(length, b.Len()-1)
-		out = append(out, b.String()[0:b.Len()-1])
 	}
+	// out of words! save off our last line.
+	length = max(length, b.Len()-1)
+	out = append(out, b.String()[0:b.Len()-1])
 	return out, length
 }
 

main_test.go

@@ -43,28 +43,37 @@ func TestGenerateCow(t *testing.T) {
 			expected: string(must(os.ReadFile("./testdata/basic.cow"))),
 		},
 		{
-			name: "multiline test",
+			name: "single-paragraph test",
 			args: args{
 				cow: string(must(os.ReadFile("./cows/default.cow"))),
 				say: "test\ntext",
 				opt: defaultOptions,
 			},
-			expected: string(must(os.ReadFile("./testdata/multiline.cow"))),
+			expected: string(must(os.ReadFile("./testdata/one_paragraph.cow"))),
 		},
 		{
 			name: "multiline with wordwrap test",
 			args: args{
 				cow: string(must(os.ReadFile("./cows/default.cow"))),
-				say: "this is a long block of text.\n\n\nIt goes over many lines! It'll even word-wrap for us.",
+				say: "this is a long block of text.\nIt goes over many lines! It'll even word-wrap for us.",
 				opt: defaultOptions,
 			},
 			expected: string(must(os.ReadFile("./testdata/longer_multiline.cow"))),
 		},
+		{
+			name: "two-paragraph multiline with wordwrap test",
+			args: args{
+				cow: string(must(os.ReadFile("./cows/default.cow"))),
+				say: "this is a long block of text.\n\nIt goes over many lines! It'll even word-wrap for us.",
+				opt: defaultOptions,
+			},
+			expected: string(must(os.ReadFile("./testdata/two_paragraph_multiline.cow"))),
+		},
 		{
 			name: "offset bubble",
 			args: args{
 				cow: string(must(os.ReadFile("./cows/dragon-and-cow.cow"))),
-				say: "this is a long block of text.\n\n\nIt goes over many lines! It'll even word-wrap for us.",
+				say: "this is a long block of text.\nIt goes over many lines! It'll even word-wrap for us.",
 				opt: defaultOptions,
 			},
 			expected: string(must(os.ReadFile("./testdata/dragon.cow"))),
@@ -105,6 +114,25 @@ func TestGenerateCow(t *testing.T) {
 			},
 			expected: string(must(os.ReadFile("./testdata/too_long.cow"))),
 		},
+		{
+			name: "fortune cow",
+			args: args{
+				cow: string(must(os.ReadFile("./cows/default.cow"))),
+				say: `Most people eat as though they were fattening themselves for market.
+                -- E.W. Howe`,
+				opt: defaultOptions,
+			},
+			expected: string(must(os.ReadFile("./testdata/fortune.cow"))),
+		},
+		{
+			name: "trailing space cow",
+			args: args{
+				cow: string(must(os.ReadFile("./cows/default.cow"))),
+				say: `test  `,
+				opt: defaultOptions,
+			},
+			expected: string(must(os.ReadFile("./testdata/trailing_space.cow"))),
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {

testdata/dragon.cow

@@ -1,10 +1,8 @@
-                 _____________________________________ 
-                / this is a long block of text.       \
-                |                                     |
-                |                                     |
-                | It goes over many lines! It'll even |
-                \ word-wrap for us.                   /
-                 ------------------------------------- 
+                 _______________________________________ 
+                / this is a long block of text. It goes \
+                | over many lines! It'll even word-wrap |
+                \ for us.                               /
+                 --------------------------------------- 
                        \                    ^    /^
                         \                  / \  // \
                          \   |\___/|      /   \//  .\

testdata/fortune.cow

@@ -0,0 +1,11 @@
+ _____________________________________ 
+/ Most people eat as though they were \
+| fattening themselves for market.    |
+|                                     |
+\ -- E.W. Howe                        /
+ ------------------------------------- 
+        \   ^__^
+         \  (oo)\_______
+            (__)\       )\/\
+                ||----w |
+                ||     ||

testdata/fuzz/FuzzCow/7b9a589d5aa859e5

@@ -0,0 +1,2 @@
+go test fuzz v1
+string("0 \n0")

testdata/fuzz/FuzzCow/93d7daf11243d295

@@ -0,0 +1,2 @@
+go test fuzz v1
+string("0000000000000000000000000000000000000000000000000000000000000000000000000000000")

testdata/fuzz/FuzzCow/ceaa3f997e266d98

@@ -0,0 +1,2 @@
+go test fuzz v1
+string("0 \n 0")

testdata/fuzz/FuzzCow/dde7a120ccdf11af

@@ -0,0 +1,2 @@
+go test fuzz v1
+string("0\r0")

testdata/longer_multiline.cow

@@ -1,10 +1,8 @@
- _____________________________________ 
-/ this is a long block of text.       \
-|                                     |
-|                                     |
-| It goes over many lines! It'll even |
-\ word-wrap for us.                   /
- ------------------------------------- 
+ _______________________________________ 
+/ this is a long block of text. It goes \
+| over many lines! It'll even word-wrap |
+\ for us.                               /
+ --------------------------------------- 
         \   ^__^
          \  (oo)\_______
             (__)\       )\/\

testdata/one_paragraph.cow

@@ -0,0 +1,8 @@
+ ___________ 
+< test text >
+ ----------- 
+        \   ^__^
+         \  (oo)\_______
+            (__)\       )\/\
+                ||----w |
+                ||     ||

testdata/trailing_space.cow

@@ -1,7 +1,6 @@
- ______ 
-/ test \
-\ text /
- ------ 
+ _______ 
+< test  >
+ ------- 
         \   ^__^
          \  (oo)\_______
             (__)\       )\/\

testdata/two_paragraph_multiline.cow

@@ -0,0 +1,11 @@
+ _____________________________________ 
+/ this is a long block of text.       \
+|                                     |
+| It goes over many lines! It'll even |
+\ word-wrap for us.                   /
+ ------------------------------------- 
+        \   ^__^
+         \  (oo)\_______
+            (__)\       )\/\
+                ||----w |
+                ||     ||