refactor: use sourcegraph/run for command execution

blob.go

@@ -19,21 +19,20 @@ type Blob struct {
 // can be very slow and memory consuming for huge content.
 func (b *Blob) Bytes(ctx context.Context) ([]byte, error) {
 	stdout := new(bytes.Buffer)
-	stderr := new(bytes.Buffer)
 
 	// Preallocate memory to save ~50% memory usage on big files.
 	if size := b.Size(ctx); size > 0 && size < int64(^uint(0)>>1) {
 		stdout.Grow(int(size))
 	}
 
-	if err := b.Pipeline(ctx, stdout, stderr); err != nil {
-		return nil, concatenateError(err, stderr.String())
+	if err := b.Pipeline(ctx, stdout, nil); err != nil {
+		return nil, err
 	}
 	return stdout.Bytes(), nil
 }
 
 // Pipeline reads the content of the blob and pipes stdout and stderr to
 // supplied io.Writer.
 func (b *Blob) Pipeline(ctx context.Context, stdout, stderr io.Writer) error {
-	return NewCommand(ctx, "show", b.id.String()).RunInDirPipeline(stdout, stderr, b.parent.repo.path)
+	return gitPipeline(ctx, b.parent.repo.path, []string{"show", b.id.String()}, nil, stdout, stderr, nil)
 }