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// 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)
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)
}