.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201105173854-bc9fc8d8c4bc/internal/lsp/diff/difftest/difftest_test.go

   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.
   4
   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"
   8 package difftest_test
   9
  10 import (
  11         "fmt"
  12         "io/ioutil"
  13         "os"
  14         "os/exec"
  15         "strings"
  16         "testing"
  17
  18         "golang.org/x/tools/internal/lsp/diff/difftest"
  19         "golang.org/x/tools/internal/testenv"
  20 )
  21
  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) {
  26                         t.Helper()
  27                         if test.NoDiff {
  28                                 t.Skip("diff tool produces expected different results")
  29                         }
  30                         diff, err := getDiffOutput(test.In, test.Out)
  31                         if err != nil {
  32                                 t.Fatal(err)
  33                         }
  34                         if len(diff) > 0 {
  35                                 diff = difftest.UnifiedPrefix + diff
  36                         }
  37                         if diff != test.Unified {
  38                                 t.Errorf("unified:\n%q\ndiff -u:\n%q", test.Unified, diff)
  39                         }
  40                 })
  41         }
  42 }
  43
  44 func getDiffOutput(a, b string) (string, error) {
  45         fileA, err := ioutil.TempFile("", "myers.in")
  46         if err != nil {
  47                 return "", err
  48         }
  49         defer os.Remove(fileA.Name())
  50         if _, err := fileA.Write([]byte(a)); err != nil {
  51                 return "", err
  52         }
  53         if err := fileA.Close(); err != nil {
  54                 return "", err
  55         }
  56         fileB, err := ioutil.TempFile("", "myers.in")
  57         if err != nil {
  58                 return "", err
  59         }
  60         defer os.Remove(fileB.Name())
  61         if _, err := fileB.Write([]byte(b)); err != nil {
  62                 return "", err
  63         }
  64         if err := fileB.Close(); err != nil {
  65                 return "", err
  66         }
  67         cmd := exec.Command("diff", "-u", fileA.Name(), fileB.Name())
  68         out, err := cmd.CombinedOutput()
  69         if err != nil {
  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))
  72                 }
  73         }
  74         diff := string(out)
  75         if len(diff) <= 0 {
  76                 return diff, nil
  77         }
  78         bits := strings.SplitN(diff, "\n", 3)
  79         if len(bits) != 3 {
  80                 return "", fmt.Errorf("diff output did not have file prefix:\n%s", diff)
  81         }
  82         return bits[2], nil
  83 }