Try to figure out attribute checker problem (#33901)

For #31600

modules/git/repo_attribute_test.go

@@ -4,10 +4,16 @@
 package git
 
 import (
+	"context"
+	mathRand "math/rand/v2"
+	"path/filepath"
+	"slices"
+	"sync"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func Test_nulSeparatedAttributeWriter_ReadAttribute(t *testing.T) {
@@ -95,3 +101,57 @@ func Test_nulSeparatedAttributeWriter_ReadAttribute(t *testing.T) {
 		Value:     "unspecified",
 	}, attr)
 }
+
+func TestAttributeReader(t *testing.T) {
+	t.Skip() // for debug purpose only, do not run in CI
+
+	ctx := t.Context()
+
+	timeout := 1 * time.Second
+	repoPath := filepath.Join(testReposDir, "language_stats_repo")
+	commitRef := "HEAD"
+
+	oneRound := func(t *testing.T, roundIdx int) {
+		ctx, cancel := context.WithTimeout(ctx, timeout)
+		_ = cancel
+		gitRepo, err := OpenRepository(ctx, repoPath)
+		require.NoError(t, err)
+		defer gitRepo.Close()
+
+		commit, err := gitRepo.GetCommit(commitRef)
+		require.NoError(t, err)
+
+		files, err := gitRepo.LsFiles()
+		require.NoError(t, err)
+
+		randomFiles := slices.Clone(files)
+		randomFiles = append(randomFiles, "any-file-1", "any-file-2")
+
+		t.Logf("Round %v with %d files", roundIdx, len(randomFiles))
+
+		attrReader, deferrable := gitRepo.CheckAttributeReader(commit.ID.String())
+		defer deferrable()
+
+		wg := sync.WaitGroup{}
+		wg.Add(1)
+
+		go func() {
+			for {
+				file := randomFiles[mathRand.IntN(len(randomFiles))]
+				_, err := attrReader.CheckPath(file)
+				if err != nil {
+					for i := 0; i < 10; i++ {
+						_, _ = attrReader.CheckPath(file)
+					}
+					break
+				}
+			}
+			wg.Done()
+		}()
+		wg.Wait()
+	}
+
+	for i := 0; i < 100; i++ {
+		oneRound(t, i)
+	}
+}