demo for why the tags are all closed

Author: wxiaoguang

services/gitdiff/gitdiff.go

@@ -295,6 +295,8 @@ type highlightCodeDiff struct {
 	placeholderTagMap   map[rune]string
 	tagPlaceholderMap   map[string]rune
 
+	placeholderOverflowCount int
+
 	lineWrapperTags []string
 }
 
@@ -410,9 +412,11 @@ func (hcd *highlightCodeDiff) convertToPlaceholders(htmlCode string) string {
 
 		if placeholder != 0 {
 			res.WriteRune(placeholder) // use the placeholder to replace the tag
+		} else {
+			// unfortunately, all private use runes has been exhausted, no more placeholder could be used, no more converting
+			// usually, the exhausting won't occur in real cases, the magnitude of used placeholders is not larger than that of the CSS classes outputted by chroma.
+			hcd.placeholderOverflowCount++
 		}
-		// else: unfortunately, all private use runes has been exhausted, no more placeholder could be used, no more converting
-		// usually, the exhausting won't occur in real cases, the magnitude of used placeholders is not larger than that of the CSS classes outputted by chroma.
 	}
 	// write the remaining string
 	res.WriteString(htmlCode)

services/gitdiff/gitdiff_test.go

@@ -684,6 +684,29 @@ func TestDiffWithHighlightPlaceholder(t *testing.T) {
 	expected = fmt.Sprintf(`<span class="nx">a</span><span class="o">=</span><span class="s1">&#39;</span><span class="added-code">%s</span>&#39;`, "\uF8FF")
 	output = diffToHTML(nil, diffs, DiffLineAdd)
 	assert.Equal(t, expected, output)
+
+	totalOverflow := 0
+	for i := 0; i < 100; i++ {
+		hcd = newHighlightCodeDiff()
+		hcd.placeholderMaxCount = i
+		diffs = hcd.diffWithHighlight(
+			"main.js", "",
+			"a='1'",
+			"b='2'",
+		)
+		totalOverflow += hcd.placeholderOverflowCount
+
+		output = diffToHTML(nil, diffs, DiffLineDel)
+		c1 := strings.Count(output, "<span")
+		c2 := strings.Count(output, "</span")
+		assert.Equal(t, c1, c2)
+
+		output = diffToHTML(nil, diffs, DiffLineAdd)
+		c1 = strings.Count(output, "<span")
+		c2 = strings.Count(output, "</span")
+		assert.Equal(t, c1, c2)
+	}
+	assert.NotZero(t, totalOverflow)
 }
 
 func TestNoCrashes(t *testing.T) {