feat: highlighted code search results (#4749)

closes #4534

<details>
<summary>Screenshots</summary>

![](https://codeberg.org/attachments/0ab8a7b0-6485-46dc-a730-c016abb1f287)
</details>

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/4749
Reviewed-by: 0ko <0ko@noreply.codeberg.org>
Co-authored-by: Shiny Nematoda <snematoda.751k2@aleeas.com>
Co-committed-by: Shiny Nematoda <snematoda.751k2@aleeas.com>

modules/git/grep.go

@@ -1,4 +1,5 @@
 // Copyright 2024 The Gitea Authors. All rights reserved.
+// Copyright 2024 The Forgejo Authors. All rights reserved.
 // SPDX-License-Identifier: MIT
 
 package git
@@ -19,9 +20,10 @@ import (
 )
 
 type GrepResult struct {
-	Filename    string
-	LineNumbers []int
-	LineCodes   []string
+	Filename          string
+	LineNumbers       []int
+	LineCodes         []string
+	HighlightedRanges [][3]int
 }
 
 type GrepOptions struct {
@@ -33,6 +35,13 @@ type GrepOptions struct {
 	PathSpec          []setting.Glob
 }
 
+func hasPrefixFold(s, t string) bool {
+	if len(s) < len(t) {
+		return false
+	}
+	return strings.EqualFold(s[:len(t)], t)
+}
+
 func GrepSearch(ctx context.Context, repo *Repository, search string, opts GrepOptions) ([]*GrepResult, error) {
 	stdoutReader, stdoutWriter, err := os.Pipe()
 	if err != nil {
@@ -53,18 +62,19 @@ func GrepSearch(ctx context.Context, repo *Repository, search string, opts GrepO
 	 2^@repo: go-gitea/gitea
 	*/
 	var results []*GrepResult
-	cmd := NewCommand(ctx, "grep", "--null", "--break", "--heading", "--fixed-strings", "--line-number", "--ignore-case", "--full-name")
+	cmd := NewCommand(ctx, "grep",
+		"--null", "--break", "--heading", "--column",
+		"--fixed-strings", "--line-number", "--ignore-case", "--full-name")
 	cmd.AddOptionValues("--context", fmt.Sprint(opts.ContextLineNumber))
 	if opts.MatchesPerFile > 0 {
 		cmd.AddOptionValues("--max-count", fmt.Sprint(opts.MatchesPerFile))
 	}
+	words := []string{search}
 	if opts.IsFuzzy {
-		words := strings.Fields(search)
-		for _, word := range words {
-			cmd.AddOptionValues("-e", strings.TrimLeft(word, "-"))
-		}
-	} else {
-		cmd.AddOptionValues("-e", strings.TrimLeft(search, "-"))
+		words = strings.Fields(search)
+	}
+	for _, word := range words {
+		cmd.AddOptionValues("-e", strings.TrimLeft(word, "-"))
 	}
 
 	// pathspec
@@ -128,6 +138,24 @@ func GrepSearch(ctx context.Context, repo *Repository, search string, opts GrepO
 				if lineNum, lineCode, ok := strings.Cut(line, "\x00"); ok {
 					lineNumInt, _ := strconv.Atoi(lineNum)
 					res.LineNumbers = append(res.LineNumbers, lineNumInt)
+					if lineCol, lineCode2, ok := strings.Cut(lineCode, "\x00"); ok {
+						lineColInt, _ := strconv.Atoi(lineCol)
+						start := lineColInt - 1
+						matchLen := len(lineCode2)
+						for _, word := range words {
+							if hasPrefixFold(lineCode2[start:], word) {
+								matchLen = len(word)
+								break
+							}
+						}
+						res.HighlightedRanges = append(res.HighlightedRanges, [3]int{
+							len(res.LineCodes),
+							start,
+							start + matchLen,
+						})
+						res.LineCodes = append(res.LineCodes, lineCode2)
+						continue
+					}
 					res.LineCodes = append(res.LineCodes, lineCode)
 				}
 			}

modules/git/grep_test.go

@@ -20,28 +20,43 @@ func TestGrepSearch(t *testing.T) {
 	require.NoError(t, err)
 	defer repo.Close()
 
-	res, err := GrepSearch(context.Background(), repo, "void", GrepOptions{})
+	res, err := GrepSearch(context.Background(), repo, "public", GrepOptions{})
 	require.NoError(t, err)
 	assert.Equal(t, []*GrepResult{
 		{
 			Filename:    "java-hello/main.java",
-			LineNumbers: []int{3},
-			LineCodes:   []string{" public static void main(String[] args)"},
+			LineNumbers: []int{1, 3},
+			LineCodes: []string{
+				"public class HelloWorld",
+				" public static void main(String[] args)",
+			},
+			HighlightedRanges: [][3]int{{0, 0, 6}, {1, 1, 7}},
 		},
 		{
 			Filename:    "main.vendor.java",
-			LineNumbers: []int{3},
-			LineCodes:   []string{" public static void main(String[] args)"},
+			LineNumbers: []int{1, 3},
+			LineCodes: []string{
+				"public class HelloWorld",
+				" public static void main(String[] args)",
+			},
+			HighlightedRanges: [][3]int{{0, 0, 6}, {1, 1, 7}},
 		},
 	}, res)
 
-	res, err = GrepSearch(context.Background(), repo, "void", GrepOptions{MaxResultLimit: 1})
+	res, err = GrepSearch(context.Background(), repo, "void", GrepOptions{MaxResultLimit: 1, ContextLineNumber: 2})
 	require.NoError(t, err)
 	assert.Equal(t, []*GrepResult{
 		{
 			Filename:    "java-hello/main.java",
-			LineNumbers: []int{3},
-			LineCodes:   []string{" public static void main(String[] args)"},
+			LineNumbers: []int{1, 2, 3, 4, 5},
+			LineCodes: []string{
+				"public class HelloWorld",
+				"{",
+				" public static void main(String[] args)",
+				" {",
+				"  System.out.println(\"Hello world!\");",
+			},
+			HighlightedRanges: [][3]int{{2, 15, 19}},
 		},
 	}, res)
 
@@ -49,24 +64,28 @@ func TestGrepSearch(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, []*GrepResult{
 		{
-			Filename:    "i-am-a-python.p",
-			LineNumbers: []int{1},
-			LineCodes:   []string{"## This is a simple file to do a hello world"},
+			Filename:          "i-am-a-python.p",
+			LineNumbers:       []int{1},
+			LineCodes:         []string{"## This is a simple file to do a hello world"},
+			HighlightedRanges: [][3]int{{0, 39, 44}},
 		},
 		{
-			Filename:    "java-hello/main.java",
-			LineNumbers: []int{1},
-			LineCodes:   []string{"public class HelloWorld"},
+			Filename:          "java-hello/main.java",
+			LineNumbers:       []int{1},
+			LineCodes:         []string{"public class HelloWorld"},
+			HighlightedRanges: [][3]int{{0, 18, 23}},
 		},
 		{
-			Filename:    "main.vendor.java",
-			LineNumbers: []int{1},
-			LineCodes:   []string{"public class HelloWorld"},
+			Filename:          "main.vendor.java",
+			LineNumbers:       []int{1},
+			LineCodes:         []string{"public class HelloWorld"},
+			HighlightedRanges: [][3]int{{0, 18, 23}},
 		},
 		{
-			Filename:    "python-hello/hello.py",
-			LineNumbers: []int{1},
-			LineCodes:   []string{"## This is a simple file to do a hello world"},
+			Filename:          "python-hello/hello.py",
+			LineNumbers:       []int{1},
+			LineCodes:         []string{"## This is a simple file to do a hello world"},
+			HighlightedRanges: [][3]int{{0, 39, 44}},
 		},
 	}, res)
 

modules/indexer/code/search.go

@@ -12,6 +12,7 @@ import (
 	"code.gitea.io/gitea/modules/highlight"
 	"code.gitea.io/gitea/modules/indexer/code/internal"
 	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/services/gitdiff"
 )
 
 // Result a search result to display
@@ -70,11 +71,85 @@ func writeStrings(buf *bytes.Buffer, strs ...string) error {
 	return nil
 }
 
-func HighlightSearchResultCode(filename string, lineNums []int, code string) []ResultLine {
+const (
+	highlightTagStart = "<span class=\"search-highlight\">"
+	highlightTagEnd   = "</span>"
+)
+
+func HighlightSearchResultCode(filename string, lineNums []int, highlightRanges [][3]int, code string) []ResultLine {
+	hcd := gitdiff.NewHighlightCodeDiff()
+	hcd.CollectUsedRunes(code)
+	startTag, endTag := hcd.NextPlaceholder(), hcd.NextPlaceholder()
+	hcd.PlaceholderTokenMap[startTag] = highlightTagStart
+	hcd.PlaceholderTokenMap[endTag] = highlightTagEnd
+
 	// we should highlight the whole code block first, otherwise it doesn't work well with multiple line highlighting
 	hl, _ := highlight.Code(filename, "", code)
-	highlightedLines := strings.Split(string(hl), "\n")
+	conv := hcd.ConvertToPlaceholders(string(hl))
+	convLines := strings.Split(conv, "\n")
 
+	// each highlightRange is of the form [line number, start pos, end pos]
+	for _, highlightRange := range highlightRanges {
+		ln, start, end := highlightRange[0], highlightRange[1], highlightRange[2]
+		line := convLines[ln]
+		if line == "" || len(line) <= start || len(line) < end {
+			continue
+		}
+
+		sb := strings.Builder{}
+		count := -1
+		isOpen := false
+		for _, r := range line {
+			if token, ok := hcd.PlaceholderTokenMap[r];
+			// token was not found
+			!ok ||
+				// token was marked as used
+				token == "" ||
+				// the token is not an valid html tag emited by chroma
+				!(len(token) > 6 && (token[0:5] == "<span" || token[0:6] == "</span")) {
+				count++
+			} else if !isOpen {
+				// open the tag only after all other placeholders
+				sb.WriteRune(r)
+				continue
+			} else if isOpen && count < end {
+				// if the tag is open, but a placeholder exists in between
+				// close the tag
+				sb.WriteRune(endTag)
+				// write the placeholder
+				sb.WriteRune(r)
+				// reopen the tag
+				sb.WriteRune(startTag)
+				continue
+			}
+
+			switch count {
+			case end:
+				// if tag is not open, no need to close
+				if !isOpen {
+					break
+				}
+				sb.WriteRune(endTag)
+				isOpen = false
+			case start:
+				// if tag is open, do not open again
+				if isOpen {
+					break
+				}
+				isOpen = true
+				sb.WriteRune(startTag)
+			}
+
+			sb.WriteRune(r)
+		}
+		if isOpen {
+			sb.WriteRune(endTag)
+		}
+		convLines[ln] = sb.String()
+	}
+	conv = strings.Join(convLines, "\n")
+
+	highlightedLines := strings.Split(hcd.Recover(conv), "\n")
 	// The lineNums outputted by highlight.Code might not match the original lineNums, because "highlight" removes the last `\n`
 	lines := make([]ResultLine, min(len(highlightedLines), len(lineNums)))
 	for i := 0; i < len(lines); i++ {
@@ -92,6 +167,7 @@ func searchResult(result *internal.SearchResult, startIndex, endIndex int) (*Res
 	contentLines := strings.SplitAfter(result.Content[startIndex:endIndex], "\n")
 	lineNums := make([]int, 0, len(contentLines))
 	index := startIndex
+	var highlightRanges [][3]int
 	for i, line := range contentLines {
 		var err error
 		if index < result.EndIndex &&
@@ -99,6 +175,7 @@ func searchResult(result *internal.SearchResult, startIndex, endIndex int) (*Res
 			result.StartIndex < result.EndIndex {
 			openActiveIndex := max(result.StartIndex-index, 0)
 			closeActiveIndex := min(result.EndIndex-index, len(line))
+			highlightRanges = append(highlightRanges, [3]int{i, openActiveIndex, closeActiveIndex})
 			err = writeStrings(&formattedLinesBuffer,
 				line[:openActiveIndex],
 				line[openActiveIndex:closeActiveIndex],
@@ -122,7 +199,7 @@ func searchResult(result *internal.SearchResult, startIndex, endIndex int) (*Res
 		UpdatedUnix: result.UpdatedUnix,
 		Language:    result.Language,
 		Color:       result.Color,
-		Lines:       HighlightSearchResultCode(result.Filename, lineNums, formattedLinesBuffer.String()),
+		Lines:       HighlightSearchResultCode(result.Filename, lineNums, highlightRanges, formattedLinesBuffer.String()),
 	}, nil
 }
 

routers/web/repo/search.go

@@ -85,7 +85,7 @@ func Search(ctx *context.Context) {
 				// UpdatedUnix: not supported yet
 				// Language:    not supported yet
 				// Color:       not supported yet
-				Lines: code_indexer.HighlightSearchResultCode(r.Filename, r.LineNumbers, strings.Join(r.LineCodes, "\n")),
+				Lines: code_indexer.HighlightSearchResultCode(r.Filename, r.LineNumbers, r.HighlightedRanges, strings.Join(r.LineCodes, "\n")),
 			})
 		}
 	}

services/gitdiff/gitdiff.go

@@ -337,7 +337,7 @@ func (diffSection *DiffSection) GetComputedInlineDiffFor(diffLine *DiffLine, loc
 		return DiffInlineWithHighlightCode(diffSection.FileName, language, diffLine.Content, locale)
 	}
 
-	hcd := newHighlightCodeDiff()
+	hcd := NewHighlightCodeDiff()
 	diffRecord := hcd.diffWithHighlight(diffSection.FileName, language, diff1[1:], diff2[1:])
 	// it seems that Gitea doesn't need the line wrapper of Chroma, so do not add them back
 	// if the line wrappers are still needed in the future, it can be added back by "diffToHTML(hcd.lineWrapperTags. ...)"

services/gitdiff/highlightdiff.go

@@ -31,17 +31,17 @@ func extractHTMLToken(s string) (before, token, after string, valid bool) {
 	return "", "", s, true
 }
 
-// highlightCodeDiff is used to do diff with highlighted HTML code.
+// HighlightCodeDiff is used to do diff with highlighted HTML code.
 // It totally depends on Chroma's valid HTML output and its structure, do not use these functions for other purposes.
 // The HTML tags and entities will be replaced by Unicode placeholders: "<span>{TEXT}</span>" => "\uE000{TEXT}\uE001"
 // These Unicode placeholders are friendly to the diff.
 // Then after diff, the placeholders in diff result will be recovered to the HTML tags and entities.
 // It's guaranteed that the tags in final diff result are paired correctly.
-type highlightCodeDiff struct {
+type HighlightCodeDiff struct {
 	placeholderBegin    rune
 	placeholderMaxCount int
 	placeholderIndex    int
-	placeholderTokenMap map[rune]string
+	PlaceholderTokenMap map[rune]string
 	tokenPlaceholderMap map[string]rune
 
 	placeholderOverflowCount int
@@ -49,52 +49,52 @@ type highlightCodeDiff struct {
 	lineWrapperTags []string
 }
 
-func newHighlightCodeDiff() *highlightCodeDiff {
-	return &highlightCodeDiff{
+func NewHighlightCodeDiff() *HighlightCodeDiff {
+	return &HighlightCodeDiff{
 		placeholderBegin:    rune(0x100000), // Plane 16: Supplementary Private Use Area B (U+100000..U+10FFFD)
 		placeholderMaxCount: 64000,
-		placeholderTokenMap: map[rune]string{},
+		PlaceholderTokenMap: map[rune]string{},
 		tokenPlaceholderMap: map[string]rune{},
 	}
 }
 
-// nextPlaceholder returns 0 if no more placeholder can be used
+// NextPlaceholder returns 0 if no more placeholder can be used
 // the diff is done line by line, usually there are only a few (no more than 10) placeholders in one line
 // so the placeholderMaxCount is impossible to be exhausted in real cases.
-func (hcd *highlightCodeDiff) nextPlaceholder() rune {
+func (hcd *HighlightCodeDiff) NextPlaceholder() rune {
 	for hcd.placeholderIndex < hcd.placeholderMaxCount {
 		r := hcd.placeholderBegin + rune(hcd.placeholderIndex)
 		hcd.placeholderIndex++
 		// only use non-existing (not used by code) rune as placeholders
-		if _, ok := hcd.placeholderTokenMap[r]; !ok {
+		if _, ok := hcd.PlaceholderTokenMap[r]; !ok {
 			return r
 		}
 	}
 	return 0 // no more available placeholder
 }
 
-func (hcd *highlightCodeDiff) isInPlaceholderRange(r rune) bool {
+func (hcd *HighlightCodeDiff) isInPlaceholderRange(r rune) bool {
 	return hcd.placeholderBegin <= r && r < hcd.placeholderBegin+rune(hcd.placeholderMaxCount)
 }
 
-func (hcd *highlightCodeDiff) collectUsedRunes(code string) {
+func (hcd *HighlightCodeDiff) CollectUsedRunes(code string) {
 	for _, r := range code {
 		if hcd.isInPlaceholderRange(r) {
 			// put the existing rune (used by code) in map, then this rune won't be used a placeholder anymore.
-			hcd.placeholderTokenMap[r] = ""
+			hcd.PlaceholderTokenMap[r] = ""
 		}
 	}
 }
 
-func (hcd *highlightCodeDiff) diffWithHighlight(filename, language, codeA, codeB string) []diffmatchpatch.Diff {
-	hcd.collectUsedRunes(codeA)
-	hcd.collectUsedRunes(codeB)
+func (hcd *HighlightCodeDiff) diffWithHighlight(filename, language, codeA, codeB string) []diffmatchpatch.Diff {
+	hcd.CollectUsedRunes(codeA)
+	hcd.CollectUsedRunes(codeB)
 
 	highlightCodeA, _ := highlight.Code(filename, language, codeA)
 	highlightCodeB, _ := highlight.Code(filename, language, codeB)
 
-	convertedCodeA := hcd.convertToPlaceholders(string(highlightCodeA))
-	convertedCodeB := hcd.convertToPlaceholders(string(highlightCodeB))
+	convertedCodeA := hcd.ConvertToPlaceholders(string(highlightCodeA))
+	convertedCodeB := hcd.ConvertToPlaceholders(string(highlightCodeB))
 
 	diffs := diffMatchPatch.DiffMain(convertedCodeA, convertedCodeB, true)
 	diffs = diffMatchPatch.DiffCleanupEfficiency(diffs)
@@ -106,7 +106,7 @@ func (hcd *highlightCodeDiff) diffWithHighlight(filename, language, codeA, codeB
 }
 
 // convertToPlaceholders totally depends on Chroma's valid HTML output and its structure, do not use these functions for other purposes.
-func (hcd *highlightCodeDiff) convertToPlaceholders(htmlCode string) string {
+func (hcd *HighlightCodeDiff) ConvertToPlaceholders(htmlCode string) string {
 	var tagStack []string
 	res := strings.Builder{}
 
@@ -153,10 +153,10 @@ func (hcd *highlightCodeDiff) convertToPlaceholders(htmlCode string) string {
 		// remember the placeholder and token in the map
 		placeholder, ok := hcd.tokenPlaceholderMap[tokenInMap]
 		if !ok {
-			placeholder = hcd.nextPlaceholder()
+			placeholder = hcd.NextPlaceholder()
 			if placeholder != 0 {
 				hcd.tokenPlaceholderMap[tokenInMap] = placeholder
-				hcd.placeholderTokenMap[placeholder] = tokenInMap
+				hcd.PlaceholderTokenMap[placeholder] = tokenInMap
 			}
 		}
 
@@ -179,12 +179,16 @@ func (hcd *highlightCodeDiff) convertToPlaceholders(htmlCode string) string {
 	return res.String()
 }
 
-func (hcd *highlightCodeDiff) recoverOneDiff(diff *diffmatchpatch.Diff) {
+func (hcd *HighlightCodeDiff) recoverOneDiff(diff *diffmatchpatch.Diff) {
+	diff.Text = hcd.Recover(diff.Text)
+}
+
+func (hcd *HighlightCodeDiff) Recover(src string) string {
 	sb := strings.Builder{}
 	var tagStack []string
 
-	for _, r := range diff.Text {
-		token, ok := hcd.placeholderTokenMap[r]
+	for _, r := range src {
+		token, ok := hcd.PlaceholderTokenMap[r]
 		if !ok || token == "" {
 			sb.WriteRune(r) // if the rune is not a placeholder, write it as it is
 			continue
@@ -218,5 +222,5 @@ func (hcd *highlightCodeDiff) recoverOneDiff(diff *diffmatchpatch.Diff) {
 		}
 	}
 
-	diff.Text = sb.String()
+	return sb.String()
 }

services/gitdiff/highlightdiff_test.go

@@ -13,7 +13,7 @@ import (
 )
 
 func TestDiffWithHighlight(t *testing.T) {
-	hcd := newHighlightCodeDiff()
+	hcd := NewHighlightCodeDiff()
 	diffs := hcd.diffWithHighlight(
 		"main.v", "",
 		"		run('<>')\n",
@@ -28,9 +28,9 @@ func TestDiffWithHighlight(t *testing.T) {
 	output = diffToHTML(nil, diffs, DiffLineAdd)
 	assert.Equal(t, expected, output)
 
-	hcd = newHighlightCodeDiff()
-	hcd.placeholderTokenMap['O'] = "<span>"
-	hcd.placeholderTokenMap['C'] = "</span>"
+	hcd = NewHighlightCodeDiff()
+	hcd.PlaceholderTokenMap['O'] = "<span>"
+	hcd.PlaceholderTokenMap['C'] = "</span>"
 	diff := diffmatchpatch.Diff{}
 
 	diff.Text = "OC"
@@ -47,20 +47,20 @@ func TestDiffWithHighlight(t *testing.T) {
 }
 
 func TestDiffWithHighlightPlaceholder(t *testing.T) {
-	hcd := newHighlightCodeDiff()
+	hcd := NewHighlightCodeDiff()
 	diffs := hcd.diffWithHighlight(
 		"main.js", "",
 		"a='\U00100000'",
 		"a='\U0010FFFD''",
 	)
-	assert.Equal(t, "", hcd.placeholderTokenMap[0x00100000])
-	assert.Equal(t, "", hcd.placeholderTokenMap[0x0010FFFD])
+	assert.Equal(t, "", hcd.PlaceholderTokenMap[0x00100000])
+	assert.Equal(t, "", hcd.PlaceholderTokenMap[0x0010FFFD])
 
 	expected := fmt.Sprintf(`<span class="nx">a</span><span class="o">=</span><span class="s1">&#39;</span><span class="removed-code">%s</span>&#39;`, "\U00100000")
 	output := diffToHTML(hcd.lineWrapperTags, diffs, DiffLineDel)
 	assert.Equal(t, expected, output)
 
-	hcd = newHighlightCodeDiff()
+	hcd = NewHighlightCodeDiff()
 	diffs = hcd.diffWithHighlight(
 		"main.js", "",
 		"a='\U00100000'",
@@ -72,7 +72,7 @@ func TestDiffWithHighlightPlaceholder(t *testing.T) {
 }
 
 func TestDiffWithHighlightPlaceholderExhausted(t *testing.T) {
-	hcd := newHighlightCodeDiff()
+	hcd := NewHighlightCodeDiff()
 	hcd.placeholderMaxCount = 0
 	diffs := hcd.diffWithHighlight(
 		"main.js", "",
@@ -83,7 +83,7 @@ func TestDiffWithHighlightPlaceholderExhausted(t *testing.T) {
 	expected := fmt.Sprintf(`<span class="removed-code">%s#39;</span>`, "\uFFFD")
 	assert.Equal(t, expected, output)
 
-	hcd = newHighlightCodeDiff()
+	hcd = NewHighlightCodeDiff()
 	hcd.placeholderMaxCount = 0
 	diffs = hcd.diffWithHighlight(
 		"main.js", "",
@@ -102,7 +102,7 @@ func TestDiffWithHighlightPlaceholderExhausted(t *testing.T) {
 func TestDiffWithHighlightTagMatch(t *testing.T) {
 	totalOverflow := 0
 	for i := 0; i < 100; i++ {
-		hcd := newHighlightCodeDiff()
+		hcd := NewHighlightCodeDiff()
 		hcd.placeholderMaxCount = i
 		diffs := hcd.diffWithHighlight(
 			"main.js", "",

tests/integration/explore_code_test.go

@@ -8,6 +8,7 @@ import (
 	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/tests"
 
+	"github.com/PuerkitoBio/goquery"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -15,11 +16,16 @@ func TestExploreCodeSearchIndexer(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 	defer test.MockVariableValue(&setting.Indexer.RepoIndexerEnabled, true)()
 
-	req := NewRequest(t, "GET", "/explore/code")
+	req := NewRequest(t, "GET", "/explore/code?q=file&fuzzy=true")
 	resp := MakeRequest(t, req, http.StatusOK)
+	doc := NewHTMLParser(t, resp.Body).Find(".explore")
 
-	doc := NewHTMLParser(t, resp.Body)
-	msg := doc.Find(".explore").Find(".ui.container").Find(".ui.message[data-test-tag=grep]")
+	msg := doc.
+		Find(".ui.container").
+		Find(".ui.message[data-test-tag=grep]")
+	assert.EqualValues(t, 0, msg.Length())
 
-	assert.Empty(t, msg.Nodes)
+	doc.Find(".file-body").Each(func(i int, sel *goquery.Selection) {
+		assert.Positive(t, sel.Find(".code-inner").Find(".search-highlight").Length(), 0)
+	})
 }

tests/integration/repo_search_test.go

@@ -27,7 +27,8 @@ func resultFilenames(t testing.TB, doc *HTMLDoc) []string {
 
 	result := make([]string, resultSelections.Length())
 	resultSelections.Each(func(i int, selection *goquery.Selection) {
-		assert.Positive(t, resultSelections.Find("div ol li").Length(), 0)
+		assert.Positive(t, selection.Find("div ol li").Length(), 0)
+		assert.Positive(t, selection.Find(".code-inner").Find(".search-highlight").Length(), 0)
 		result[i] = selection.
 			Find(".header").
 			Find("span.file a.file-link").

web_src/css/repo.css

@@ -1752,6 +1752,10 @@ td .commit-summary {
   color: inherit;
 }
 
+.search-highlight {
+  background: var(--color-primary-alpha-40);
+}
+
 .repository.quickstart .guide .item {
   padding: 1em;
 }