Method compareFiles

internal/diff/diff.go:327–368

(ctx context.Context, f1, f2 fs.File, fname string)

}

func (c *Comparer) compareFiles(ctx context.Context, f1, f2 fs.File, fname string) error {
	if c.DiffCommand == "" {
		return nil
	}

	oldName := "/dev/null"
	newName := "/dev/null"

	if f1 != nil {
		oldName = filepath.Join("old", fname)
		oldFile := filepath.Join(c.tmpDir, oldName)

		if err := downloadFile(ctx, f1, oldFile); err != nil {
			return errors.Wrap(err, "error downloading old file")
		}

		defer os.Remove(oldFile) //nolint:errcheck
	}

	if f2 != nil {
		newName = filepath.Join("new", fname)
		newFile := filepath.Join(c.tmpDir, newName)

		if err := downloadFile(ctx, f2, newFile); err != nil {
			return errors.Wrap(err, "error downloading new file")
		}
		defer os.Remove(newFile) //nolint:errcheck
	}

	var args []string

	args = append(args, c.DiffArguments...)
	args = append(args, oldName, newName)

	cmd := exec.CommandContext(ctx, c.DiffCommand, args...) //nolint:gosec
	cmd.Dir = c.tmpDir
	cmd.Stdout = c.out
	cmd.Stderr = c.out
	cmd.Run() //nolint:errcheck

	return nil
}

func downloadFile(ctx context.Context, f fs.File, fname string) error {
	if err := os.MkdirAll(filepath.Dir(fname), dirMode); err != nil {