mirror of https://github.com/restic/restic.git
79 lines
2.1 KiB
Go
79 lines
2.1 KiB
Go
// Copyright 2016 Google Inc. All Rights Reserved.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package pretty
|
|
|
|
import (
|
|
"fmt"
|
|
"io/ioutil"
|
|
"os"
|
|
"os/exec"
|
|
"syscall"
|
|
)
|
|
|
|
// Diff compares the pretty-printed representation of two values. The second
|
|
// return value reports whether the two values' representations are identical.
|
|
// If it is false, the first return value contains the diffs.
|
|
//
|
|
// The output labels the first value "want" and the second "got".
|
|
//
|
|
// Diff works by invoking the "diff" command. It will only succeed in
|
|
// environments where "diff" is on the shell path.
|
|
func Diff(want, got interface{}) (string, bool, error) {
|
|
fname1, err := writeToTemp(want)
|
|
if err != nil {
|
|
return "", false, err
|
|
}
|
|
defer os.Remove(fname1)
|
|
|
|
fname2, err := writeToTemp(got)
|
|
if err != nil {
|
|
return "", false, err
|
|
}
|
|
defer os.Remove(fname2)
|
|
|
|
cmd := exec.Command("diff", "-u", "--label=want", "--label=got", fname1, fname2)
|
|
out, err := cmd.Output()
|
|
if err == nil {
|
|
return string(out), true, nil
|
|
}
|
|
eerr, ok := err.(*exec.ExitError)
|
|
if !ok {
|
|
return "", false, err
|
|
}
|
|
ws, ok := eerr.Sys().(syscall.WaitStatus)
|
|
if !ok {
|
|
return "", false, err
|
|
}
|
|
if ws.ExitStatus() != 1 {
|
|
return "", false, err
|
|
}
|
|
// Exit status of 1 means no error, but diffs were found.
|
|
return string(out), false, nil
|
|
}
|
|
|
|
func writeToTemp(v interface{}) (string, error) {
|
|
f, err := ioutil.TempFile("", "prettyDiff")
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
if _, err := fmt.Fprintf(f, "%+v\n", Value(v)); err != nil {
|
|
return "", err
|
|
}
|
|
if err := f.Close(); err != nil {
|
|
return "", err
|
|
}
|
|
return f.Name(), nil
|
|
}
|