// Copyright 2019 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 diff_test import ( "bytes" "math/rand" "os" "os/exec" "path/filepath" "reflect" "strings" "testing" "unicode/utf8" "golang.org/x/tools/internal/diff" "golang.org/x/tools/internal/diff/difftest" "golang.org/x/tools/internal/testenv" ) func TestApply(t *testing.T) { for _, tc := range difftest.TestCases { t.Run(tc.Name, func(t *testing.T) { got, err := diff.Apply(tc.In, tc.Edits) if err != nil { t.Fatalf("Apply(Edits) failed: %v", err) } if got != tc.Out { t.Errorf("Apply(Edits): got %q, want %q", got, tc.Out) } if tc.LineEdits != nil { got, err := diff.Apply(tc.In, tc.LineEdits) if err != nil { t.Fatalf("Apply(LineEdits) failed: %v", err) } if got != tc.Out { t.Errorf("Apply(LineEdits): got %q, want %q", got, tc.Out) } } }) } } func TestNEdits(t *testing.T) { for _, tc := range difftest.TestCases { edits := diff.Strings(tc.In, tc.Out) got, err := diff.Apply(tc.In, edits) if err != nil { t.Fatalf("Apply failed: %v", err) } if got != tc.Out { t.Fatalf("%s: got %q wanted %q", tc.Name, got, tc.Out) } if len(edits) < len(tc.Edits) { // should find subline edits t.Errorf("got %v, expected %v for %#v", edits, tc.Edits, tc) } } } func TestNRandom(t *testing.T) { rand.Seed(1) for i := 0; i < 1000; i++ { a := randstr("abω", 16) b := randstr("abωc", 16) edits := diff.Strings(a, b) got, err := diff.Apply(a, edits) if err != nil { t.Fatalf("Apply failed: %v", err) } if got != b { t.Fatalf("%d: got %q, wanted %q, starting with %q", i, got, b, a) } } } // $ go test -fuzz=FuzzRoundTrip ./internal/diff func FuzzRoundTrip(f *testing.F) { f.Fuzz(func(t *testing.T, a, b string) { if !utf8.ValidString(a) || !utf8.ValidString(b) { return // inputs must be text } edits := diff.Strings(a, b) got, err := diff.Apply(a, edits) if err != nil { t.Fatalf("Apply failed: %v", err) } if got != b { t.Fatalf("applying diff(%q, %q) gives %q; edits=%v", a, b, got, edits) } }) } func TestLineEdits(t *testing.T) { for _, tc := range difftest.TestCases { t.Run(tc.Name, func(t *testing.T) { want := tc.LineEdits if want == nil { want = tc.Edits // already line-aligned } got, err := diff.LineEdits(tc.In, tc.Edits) if err != nil { t.Fatalf("LineEdits: %v", err) } if !reflect.DeepEqual(got, want) { t.Errorf("in=<<%s>>\nout=<<%s>>\nraw edits=%s\nline edits=%s\nwant: %s", tc.In, tc.Out, tc.Edits, got, want) } // make sure that applying the edits gives the expected result fixed, err := diff.Apply(tc.In, got) if err != nil { t.Error(err) } if fixed != tc.Out { t.Errorf("Apply(LineEdits): got %q, want %q", fixed, tc.Out) } }) } } func TestToUnified(t *testing.T) { testenv.NeedsTool(t, "patch") for _, tc := range difftest.TestCases { t.Run(tc.Name, func(t *testing.T) { unified, err := diff.ToUnified(difftest.FileA, difftest.FileB, tc.In, tc.Edits, diff.DefaultContextLines) if err != nil { t.Fatal(err) } if unified == "" { return } orig := filepath.Join(t.TempDir(), "original") err = os.WriteFile(orig, []byte(tc.In), 0644) if err != nil { t.Fatal(err) } temp := filepath.Join(t.TempDir(), "patched") err = os.WriteFile(temp, []byte(tc.In), 0644) if err != nil { t.Fatal(err) } cmd := exec.Command("patch", "-p0", "-u", "-s", "-o", temp, orig) cmd.Stdin = strings.NewReader(unified) cmd.Stdout = new(bytes.Buffer) cmd.Stderr = new(bytes.Buffer) if err = cmd.Run(); err != nil { t.Fatalf("%v: %q (%q) (%q)", err, cmd.String(), cmd.Stderr, cmd.Stdout) } got, err := os.ReadFile(temp) if err != nil { t.Fatal(err) } if string(got) != tc.Out { t.Errorf("applying unified failed: got\n%q, wanted\n%q unified\n%q", got, tc.Out, unified) } }) } } func TestRegressionOld001(t *testing.T) { a := "// Copyright 2019 The Go Authors. All rights reserved.\n// Use of this source code is governed by a BSD-style\n// license that can be found in the LICENSE file.\n\npackage diff_test\n\nimport (\n\t\"fmt\"\n\t\"math/rand\"\n\t\"strings\"\n\t\"testing\"\n\n\t\"golang.org/x/tools/gopls/internal/lsp/diff\"\n\t\"golang.org/x/tools/internal/diff/difftest\"\n\t\"golang.org/x/tools/gopls/internal/span\"\n)\n" b := "// Copyright 2019 The Go Authors. All rights reserved.\n// Use of this source code is governed by a BSD-style\n// license that can be found in the LICENSE file.\n\npackage diff_test\n\nimport (\n\t\"fmt\"\n\t\"math/rand\"\n\t\"strings\"\n\t\"testing\"\n\n\t\"github.com/google/safehtml/template\"\n\t\"golang.org/x/tools/gopls/internal/lsp/diff\"\n\t\"golang.org/x/tools/internal/diff/difftest\"\n\t\"golang.org/x/tools/gopls/internal/span\"\n)\n" diffs := diff.Strings(a, b) got, err := diff.Apply(a, diffs) if err != nil { t.Fatalf("Apply failed: %v", err) } if got != b { i := 0 for ; i < len(a) && i < len(b) && got[i] == b[i]; i++ { } t.Errorf("oops %vd\n%q\n%q", diffs, got, b) t.Errorf("\n%q\n%q", got[i:], b[i:]) } } func TestRegressionOld002(t *testing.T) { a := "n\"\n)\n" b := "n\"\n\t\"golang.org/x//nnal/stack\"\n)\n" diffs := diff.Strings(a, b) got, err := diff.Apply(a, diffs) if err != nil { t.Fatalf("Apply failed: %v", err) } if got != b { i := 0 for ; i < len(a) && i < len(b) && got[i] == b[i]; i++ { } t.Errorf("oops %vd\n%q\n%q", diffs, got, b) t.Errorf("\n%q\n%q", got[i:], b[i:]) } } // return a random string of length n made of characters from s func randstr(s string, n int) string { src := []rune(s) x := make([]rune, n) for i := 0; i < n; i++ { x[i] = src[rand.Intn(len(src))] } return string(x) }