1 // Copyright 2019 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 // Package difftest supplies a set of tests that will operate on any
6 // implementation of a diff algorithm as exposed by
7 // "golang.org/x/tools/internal/lsp/diff"
18 "golang.org/x/tools/internal/lsp/diff/difftest"
19 "golang.org/x/tools/internal/testenv"
22 func TestVerifyUnified(t *testing.T) {
23 testenv.NeedsTool(t, "diff")
24 for _, test := range difftest.TestCases {
25 t.Run(test.Name, func(t *testing.T) {
28 t.Skip("diff tool produces expected different results")
30 diff, err := getDiffOutput(test.In, test.Out)
35 diff = difftest.UnifiedPrefix + diff
37 if diff != test.Unified {
38 t.Errorf("unified:\n%q\ndiff -u:\n%q", test.Unified, diff)
44 func getDiffOutput(a, b string) (string, error) {
45 fileA, err := ioutil.TempFile("", "myers.in")
49 defer os.Remove(fileA.Name())
50 if _, err := fileA.Write([]byte(a)); err != nil {
53 if err := fileA.Close(); err != nil {
56 fileB, err := ioutil.TempFile("", "myers.in")
60 defer os.Remove(fileB.Name())
61 if _, err := fileB.Write([]byte(b)); err != nil {
64 if err := fileB.Close(); err != nil {
67 cmd := exec.Command("diff", "-u", fileA.Name(), fileB.Name())
68 out, err := cmd.CombinedOutput()
70 if _, ok := err.(*exec.ExitError); !ok {
71 return "", fmt.Errorf("failed to run diff -u %v %v: %v\n%v", fileA.Name(), fileB.Name(), err, string(out))
78 bits := strings.SplitN(diff, "\n", 3)
80 return "", fmt.Errorf("diff output did not have file prefix:\n%s", diff)