Current File : //usr/local/go119/src/cmd/gofmt/gofmt_test.go
// Copyright 2011 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 main
import (
"bytes"
"flag"
"internal/diff"
"os"
"path/filepath"
"strings"
"testing"
"text/scanner"
)
var update = flag.Bool("update", false, "update .golden files")
// gofmtFlags looks for a comment of the form
//
// //gofmt flags
//
// within the first maxLines lines of the given file,
// and returns the flags string, if any. Otherwise it
// returns the empty string.
func gofmtFlags(filename string, maxLines int) string {
f, err := os.Open(filename)
if err != nil {
return "" // ignore errors - they will be found later
}
defer f.Close()
// initialize scanner
var s scanner.Scanner
s.Init(f)
s.Error = func(*scanner.Scanner, string) {} // ignore errors
s.Mode = scanner.GoTokens &^ scanner.SkipComments // want comments
// look for //gofmt comment
for s.Line <= maxLines {
switch s.Scan() {
case scanner.Comment:
const prefix = "//gofmt "
if t := s.TokenText(); strings.HasPrefix(t, prefix) {
return strings.TrimSpace(t[len(prefix):])
}
case scanner.EOF:
return ""
}
}
return ""
}
func runTest(t *testing.T, in, out string) {
// process flags
*simplifyAST = false
*rewriteRule = ""
info, err := os.Lstat(in)
if err != nil {
t.Error(err)
return
}
for _, flag := range strings.Split(gofmtFlags(in, 20), " ") {
elts := strings.SplitN(flag, "=", 2)
name := elts[0]
value := ""
if len(elts) == 2 {
value = elts[1]
}
switch name {
case "":
// no flags
case "-r":
*rewriteRule = value
case "-s":
*simplifyAST = true
case "-stdin":
// fake flag - pretend input is from stdin
info = nil
default:
t.Errorf("unrecognized flag name: %s", name)
}
}
initParserMode()
initRewrite()
const maxWeight = 2 << 20
var buf, errBuf bytes.Buffer
s := newSequencer(maxWeight, &buf, &errBuf)
s.Add(fileWeight(in, info), func(r *reporter) error {
return processFile(in, info, nil, r)
})
if errBuf.Len() > 0 {
t.Logf("%q", errBuf.Bytes())
}
if s.GetExitCode() != 0 {
t.Fail()
}
expected, err := os.ReadFile(out)
if err != nil {
t.Error(err)
return
}
if got := buf.Bytes(); !bytes.Equal(got, expected) {
if *update {
if in != out {
if err := os.WriteFile(out, got, 0666); err != nil {
t.Error(err)
}
return
}
// in == out: don't accidentally destroy input
t.Errorf("WARNING: -update did not rewrite input file %s", in)
}
t.Errorf("(gofmt %s) != %s (see %s.gofmt)\n%s", in, out, in,
diff.Diff("expected", expected, "got", got))
if err := os.WriteFile(in+".gofmt", got, 0666); err != nil {
t.Error(err)
}
}
}
// TestRewrite processes testdata/*.input files and compares them to the
// corresponding testdata/*.golden files. The gofmt flags used to process
// a file must be provided via a comment of the form
//
// //gofmt flags
//
// in the processed file within the first 20 lines, if any.
func TestRewrite(t *testing.T) {
// determine input files
match, err := filepath.Glob("testdata/*.input")
if err != nil {
t.Fatal(err)
}
// add larger examples
match = append(match, "gofmt.go", "gofmt_test.go")
for _, in := range match {
name := filepath.Base(in)
t.Run(name, func(t *testing.T) {
out := in // for files where input and output are identical
if strings.HasSuffix(in, ".input") {
out = in[:len(in)-len(".input")] + ".golden"
}
runTest(t, in, out)
if in != out && !t.Failed() {
// Check idempotence.
runTest(t, out, out)
}
})
}
}
// Test case for issue 3961.
func TestCRLF(t *testing.T) {
const input = "testdata/crlf.input" // must contain CR/LF's
const golden = "testdata/crlf.golden" // must not contain any CR's
data, err := os.ReadFile(input)
if err != nil {
t.Error(err)
}
if !bytes.Contains(data, []byte("\r\n")) {
t.Errorf("%s contains no CR/LF's", input)
}
data, err = os.ReadFile(golden)
if err != nil {
t.Error(err)
}
if bytes.Contains(data, []byte("\r")) {
t.Errorf("%s contains CR's", golden)
}
}
func TestBackupFile(t *testing.T) {
dir, err := os.MkdirTemp("", "gofmt_test")
if err != nil {
t.Fatal(err)
}
defer os.RemoveAll(dir)
name, err := backupFile(filepath.Join(dir, "foo.go"), []byte(" package main"), 0644)
if err != nil {
t.Fatal(err)
}
t.Logf("Created: %s", name)
}
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