[FEAT] add fallback repo search using git grep

services/repository/files/search.go

@@ -0,0 +1,90 @@
+package files
+
+import (
+	"context"
+	"html/template"
+	"strconv"
+	"strings"
+
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/gitrepo"
+	"code.gitea.io/gitea/modules/highlight"
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"github.com/go-enry/go-enry/v2"
+)
+
+type Result struct {
+	RepoID         int64 // ignored
+	Filename       string
+	CommitID       string             // branch
+	UpdatedUnix    timeutil.TimeStamp // ignored
+	Language       string
+	Color          string
+	LineNumbers    []int64
+	FormattedLines template.HTML
+}
+
+const pHEAD = "HEAD:"
+
+func NewRepoGrep(ctx context.Context, repo *repo_model.Repository, keyword string) ([]*Result, error) {
+	t, _, err := gitrepo.RepositoryFromContextOrOpen(ctx, repo)
+	if err != nil {
+		return nil, err
+	}
+
+	data := []*Result{}
+
+	stdout, _, err := git.NewCommand(ctx,
+		"grep",
+		"-1", // n before and after lines
+		"-z",
+		"--heading",
+		"--break",         // easier parsing
+		"--fixed-strings", // disallow regex for now
+		"-n",              // line nums
+		"-i",              // ignore case
+		"--full-name",     // full file path, rel to repo
+		//"--column",        // for adding better highlighting support
+	).
+		AddDynamicArguments(keyword).
+		AddArguments("HEAD").
+		RunStdString(&git.RunOpts{Dir: t.Path})
+	if err != nil {
+		return data, nil // non zero exit code when there are no results
+	}
+
+	for _, block := range strings.Split(stdout, "\n\n") {
+		res := Result{CommitID: repo.DefaultBranch}
+		code := []string{}
+
+		for _, line := range strings.Split(block, "\n") {
+			if strings.HasPrefix(line, pHEAD) {
+				res.Filename = strings.TrimPrefix(line, pHEAD)
+				continue
+			}
+
+			if ln, after, ok := strings.Cut(line, "\x00"); ok {
+				i, err := strconv.ParseInt(ln, 10, 64)
+				if err != nil {
+					continue
+				}
+
+				res.LineNumbers = append(res.LineNumbers, i)
+				code = append(code, after)
+			}
+		}
+
+		if res.Filename == "" || len(code) == 0 || len(res.LineNumbers) == 0 {
+			continue
+		}
+
+		res.FormattedLines, res.Language = highlight.Code(res.Filename, "", strings.Join(code, "\n"))
+		res.Color = enry.GetColor(res.Language)
+
+		data = append(data, &res)
+	}
+
+	return data, nil
+}

services/repository/files/search_test.go

@@ -0,0 +1,48 @@
+package files
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/unittest"
+	"code.gitea.io/gitea/modules/contexttest"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewRepoGrep(t *testing.T) {
+	unittest.PrepareTestEnv(t)
+	ctx, _ := contexttest.MockContext(t, "user2/repo1")
+	ctx.SetParams(":id", "1")
+	contexttest.LoadRepo(t, ctx, 1)
+	contexttest.LoadRepoCommit(t, ctx)
+	contexttest.LoadUser(t, ctx, 2)
+	contexttest.LoadGitRepo(t, ctx)
+	defer ctx.Repo.GitRepo.Close()
+
+	t.Run("with result", func(t *testing.T) {
+		res, err := NewRepoGrep(ctx, ctx.Repo.Repository, "Description")
+		assert.NoError(t, err)
+
+		expected := []*Result{
+			{
+				RepoID:         0,
+				Filename:       "README.md",
+				CommitID:       "master",
+				UpdatedUnix:    0,
+				Language:       "Markdown",
+				Color:          "#083fa1",
+				LineNumbers:    []int64{2, 3},
+				FormattedLines: "\nDescription for repo1",
+			},
+		}
+
+		assert.EqualValues(t, res, expected)
+	})
+
+	t.Run("empty result", func(t *testing.T) {
+		res, err := NewRepoGrep(ctx, ctx.Repo.Repository, "keyword that does not match in the repo")
+		assert.NoError(t, err)
+
+		assert.EqualValues(t, res, []*Result{})
+	})
+}