Report temporary metadata cleanup failures

internal/tempdir/tempdir.go

@@ -2,6 +2,7 @@
 package tempdir
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -11,11 +12,15 @@ import (
 // Outside uses system temporary storage and falls back to the repository's
 // parent when TMPDIR resolves inside the worktree. Cleanup belongs to the caller.
 func Outside(repositoryDir, pattern string) (string, error) {
-	repository, err := filepath.Abs(repositoryDir)
+	return outside(repositoryDir, pattern, filepath.Abs, filepath.EvalSymlinks, os.RemoveAll)
+}
+
+func outside(repositoryDir, pattern string, abs, resolve func(string) (string, error), remove func(string) error) (string, error) {
+	repository, err := abs(repositoryDir)
 	if err != nil {
 		return "", err
 	}
-	repository, err = filepath.EvalSymlinks(repository)
+	repository, err = resolve(repository)
 	if err != nil {
 		return "", err
 	}
@@ -24,54 +29,54 @@ func Outside(repositoryDir, pattern string) (string, error) {
 		return "", err
 	}
 	created := directory
-	directory, err = filepath.Abs(created)
+	directory, err = abs(created)
 	if err != nil {
-		os.RemoveAll(created)
-		return "", err
+		return "", cleanupError(created, err, remove)
 	}
-	directory, err = filepath.EvalSymlinks(directory)
+	directory, err = resolve(directory)
 	if err != nil {
-		os.RemoveAll(directory)
-		return "", err
+		return "", cleanupError(created, err, remove)
 	}
 	outside, err := isOutside(repository, directory)
 	if err != nil {
-		os.RemoveAll(directory)
-		return "", err
+		return "", cleanupError(created, err, remove)
 	}
 	if outside {
 		return directory, nil
 	}
-	if err := os.RemoveAll(directory); err != nil {
-		return "", fmt.Errorf("remove temporary storage inside repository %q: %w", repository, err)
+	if err := remove(created); err != nil {
+		return "", fmt.Errorf("remove temporary storage %q: %w", created, err)
 	}
 	directory, err = os.MkdirTemp(filepath.Dir(repository), pattern)
 	if err != nil {
 		return "", fmt.Errorf("create temporary storage outside repository %q: %w", repository, err)
 	}
 	created = directory
-	directory, err = filepath.Abs(created)
+	directory, err = abs(created)
 	if err != nil {
-		os.RemoveAll(created)
-		return "", err
+		return "", cleanupError(created, err, remove)
 	}
-	directory, err = filepath.EvalSymlinks(directory)
+	directory, err = resolve(directory)
 	if err != nil {
-		os.RemoveAll(directory)
-		return "", err
+		return "", cleanupError(created, err, remove)
 	}
 	outside, err = isOutside(repository, directory)
 	if err != nil {
-		os.RemoveAll(directory)
-		return "", err
+		return "", cleanupError(created, err, remove)
 	}
 	if !outside {
-		os.RemoveAll(directory)
-		return "", fmt.Errorf("temporary storage %q is inside repository %q", directory, repository)
+		return "", cleanupError(created, fmt.Errorf("temporary storage %q is inside repository %q", directory, repository), remove)
 	}
 	return directory, nil
 }
 
+func cleanupError(path string, cause error, remove func(string) error) error {
+	if err := remove(path); err != nil {
+		return errors.Join(cause, fmt.Errorf("remove temporary storage %q: %w", path, err))
+	}
+	return cause
+}
+
 func isOutside(repository, directory string) (bool, error) {
 	if !strings.EqualFold(filepath.VolumeName(repository), filepath.VolumeName(directory)) {
 		return true, nil