Escape Whitespace in DiffPrettyText

Displace escape sequence for whitespace characters in diffs.

Author: cwarden

diffmatchpatch/diff.go

@@ -1138,6 +1138,30 @@ func (dmp *DiffMatchPatch) DiffPrettyHtml(diffs []Diff) string {
 	return buff.String()
 }
 
+func escapeWhitespace(input string) string {
+	// Define a map of whitespace characters and their escaped versions
+	escapeMap := map[string]string{
+		"\n": "\\n",
+		"\t": "\\t",
+		"\r": "\\r",
+		" ":  "\\s",
+	}
+
+	// Use a regular expression to match all whitespace characters
+	re := regexp.MustCompile(`\s`)
+
+	// Replace each whitespace character using the escapeMap
+	result := re.ReplaceAllStringFunc(input, func(match string) string {
+		escaped, exists := escapeMap[match]
+		if !exists {
+			escaped = fmt.Sprintf("\\x%x", match[0]) // Default escape for unknown whitespace
+		}
+		return escaped
+	})
+
+	return result
+}
+
 // DiffPrettyText converts a []Diff into a colored text report.
 func (dmp *DiffMatchPatch) DiffPrettyText(diffs []Diff) string {
 	var buff bytes.Buffer
@@ -1146,10 +1170,12 @@ func (dmp *DiffMatchPatch) DiffPrettyText(diffs []Diff) string {
 
 		switch diff.Type {
 		case DiffInsert:
+			text = escapeWhitespace(text)
 			_, _ = buff.WriteString("\x1b[32m")
 			_, _ = buff.WriteString(text)
 			_, _ = buff.WriteString("\x1b[0m")
 		case DiffDelete:
+			text = escapeWhitespace(text)
 			_, _ = buff.WriteString("\x1b[31m")
 			_, _ = buff.WriteString(text)
 			_, _ = buff.WriteString("\x1b[0m")

diffmatchpatch/diff_test.go

@@ -1031,6 +1031,15 @@ func TestDiffPrettyText(t *testing.T) {
 
 			Expected: "a\n\x1b[31m<B>b</B>\x1b[0m\x1b[32mc&d\x1b[0m",
 		},
+		{
+			Diffs: []Diff{
+				{DiffEqual, "a\n"},
+				{DiffDelete, "\n"},
+				{DiffInsert, "c\td e"},
+			},
+
+			Expected: "a\n\x1b[31m\\n\x1b[0m\x1b[32mc\\td\\se\x1b[0m",
+		},
 	} {
 		actual := dmp.DiffPrettyText(tc.Diffs)
 		assert.Equal(t, tc.Expected, actual, fmt.Sprintf("Test case #%d, %#v", i, tc))