blob: 0563fcd06f32b8b4006047e884ea54c484d6728c [file] [log] [blame]
// Copyright 2022 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package compare
import (
// Text returns a formatted unified diff of the edits to go from want to
// got, returning "" if and only if want == got.
// This function is intended for use in testing, and panics if any error occurs
// while computing the diff. It is not sufficiently tested for production use.
func Text(want, got string) string {
if want == got {
return ""
// Add newlines to avoid verbose newline messages ("No newline at end of file").
want += "\n"
got += "\n"
edits := diff.Strings(want, got)
diff := diff.Unified("want", "got", want, edits)
// Defensively assert that we get an actual diff, so that we guarantee the
// invariant that we return "" if and only if want == got.
// This is probably unnecessary, but convenient.
if diff == "" {
panic("empty diff for non-identical input")
return diff