gofmt: add test framework in Go

- replaced existing testdata/test.sh with new gofmt_test
- added initial test case for rewrite tests

TODO: Need to add more tests.

R=rsc
CC=golang-dev
https://golang.org/cl/4368063

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"
+	"io/ioutil"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+
+func runTest(t *testing.T, dirname, in, out, flags string) {
+	in = filepath.Join(dirname, in)
+	out = filepath.Join(dirname, out)
+
+	// process flags
+	*simplifyAST = false
+	*rewriteRule = ""
+	for _, flag := range strings.Split(flags, " ", -1) {
+		elts := strings.Split(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
+		default:
+			t.Errorf("unrecognized flag name: %s", name)
+		}
+	}
+
+	initParserMode()
+	initPrinterMode()
+	initRewrite()
+
+	var buf bytes.Buffer
+	err := processFile(in, nil, &buf)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	expected, err := ioutil.ReadFile(out)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	if got := buf.Bytes(); bytes.Compare(got, expected) != 0 {
+		t.Errorf("(gofmt %s) != %s (see %s.gofmt)", in, out, in)
+		ioutil.WriteFile(in+".gofmt", got, 0666)
+	}
+}
+
+
+// TODO(gri) Add more test cases!
+var tests = []struct {
+	dirname, in, out, flags string
+}{
+	{".", "gofmt.go", "gofmt.go", ""},
+	{".", "gofmt_test.go", "gofmt_test.go", ""},
+	{"testdata", "composites.input", "composites.golden", "-s"},
+	{"testdata", "rewrite1.input", "rewrite1.golden", "-r=Foo->Bar"},
+}
+
+
+func TestRewrite(t *testing.T) {
+	for _, test := range tests {
+		runTest(t, test.dirname, test.in, test.out, test.flags)
+	}
+}

src/cmd/gofmt/testdata/rewrite1.golden

+package main
+
+type Bar int
+
+func main() {
+	var a Bar
+	println(a)
+}

src/cmd/gofmt/testdata/rewrite1.input

+package main
+
+type Foo int
+
+func main() {
+	var a Foo
+	println(a)
+}

src/cmd/gofmt/testdata/test.sh

-#!/usr/bin/env bash
-# Copyright 2010 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.
-
-CMD="../gofmt"
-TMP=test_tmp.go
-COUNT=0
-
-
-cleanup() {
-	rm -f $TMP
-}
-
-
-error() {
-	echo $1
-	exit 1
-}
-
-
-count() {
-	#echo $1
-	let COUNT=$COUNT+1
-	let M=$COUNT%10
-	if [ $M == 0 ]; then
-		echo -n "."
-	fi
-}
-
-
-test() {
-	count $1
-
-	# compare against .golden file
-	cleanup
-	$CMD -s $1 > $TMP
-	cmp -s $TMP $2
-	if [ $? != 0 ]; then
-		diff $TMP $2
-		error "Error: simplified $1 does not match $2"
-	fi
-
-	# make sure .golden is idempotent
-	cleanup
-	$CMD -s $2 > $TMP
-	cmp -s $TMP $2
-	if [ $? != 0 ]; then
-		diff $TMP $2
-		error "Error: $2 is not idempotent"
-	fi
-}
-
-
-runtests() {
-	smoketest=../../../pkg/go/parser/parser.go
-	test $smoketest $smoketest
-	test composites.input composites.golden
-	# add more test cases here
-}
-
-
-runtests
-cleanup
-echo "PASSED ($COUNT tests)"