summaryrefslogtreecommitdiffstats
path: root/src/cmd/fix/main_test.go
blob: 2b293077d13f6df09d8b5373cd57bc7ae1c0f408 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
// 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 (
	"fmt"
	"go/ast"
	"go/parser"
	"internal/diff"
	"internal/testenv"
	"strings"
	"testing"
)

func init() {
	// If cgo is enabled, enforce that cgo commands invoked by cmd/fix
	// do not fail during testing.
	if testenv.HasCGO() && testenv.HasGoBuild() {
		// The reportCgoError hook is global, so we can't set it per-test
		// if we want to be able to run those tests in parallel.
		// Instead, simply set it to panic on error: the goroutine dump
		// from the panic should help us determine which test failed.
		reportCgoError = func(err error) {
			panic(fmt.Sprintf("unexpected cgo error: %v", err))
		}
	}
}

type testCase struct {
	Name    string
	Fn      func(*ast.File) bool
	Version int
	In      string
	Out     string
}

var testCases []testCase

func addTestCases(t []testCase, fn func(*ast.File) bool) {
	// Fill in fn to avoid repetition in definitions.
	if fn != nil {
		for i := range t {
			if t[i].Fn == nil {
				t[i].Fn = fn
			}
		}
	}
	testCases = append(testCases, t...)
}

func fnop(*ast.File) bool { return false }

func parseFixPrint(t *testing.T, fn func(*ast.File) bool, desc, in string, mustBeGofmt bool) (out string, fixed, ok bool) {
	file, err := parser.ParseFile(fset, desc, in, parserMode)
	if err != nil {
		t.Errorf("parsing: %v", err)
		return
	}

	outb, err := gofmtFile(file)
	if err != nil {
		t.Errorf("printing: %v", err)
		return
	}
	if s := string(outb); in != s && mustBeGofmt {
		t.Errorf("not gofmt-formatted.\n--- %s\n%s\n--- %s | gofmt\n%s",
			desc, in, desc, s)
		tdiff(t, "want", in, "have", s)
		return
	}

	if fn == nil {
		for _, fix := range fixes {
			if fix.f(file) {
				fixed = true
			}
		}
	} else {
		fixed = fn(file)
	}

	outb, err = gofmtFile(file)
	if err != nil {
		t.Errorf("printing: %v", err)
		return
	}

	return string(outb), fixed, true
}

func TestRewrite(t *testing.T) {
	for _, tt := range testCases {
		tt := tt
		t.Run(tt.Name, func(t *testing.T) {
			if tt.Version == 0 {
				if testing.Verbose() {
					// Don't run in parallel: cmd/fix sometimes writes directly to stderr,
					// and since -v prints which test is currently running we want that
					// information to accurately correlate with the stderr output.
				} else {
					t.Parallel()
				}
			} else {
				old := goVersion
				goVersion = tt.Version
				defer func() {
					goVersion = old
				}()
			}

			// Apply fix: should get tt.Out.
			out, fixed, ok := parseFixPrint(t, tt.Fn, tt.Name, tt.In, true)
			if !ok {
				return
			}

			// reformat to get printing right
			out, _, ok = parseFixPrint(t, fnop, tt.Name, out, false)
			if !ok {
				return
			}

			if tt.Out == "" {
				tt.Out = tt.In
			}
			if out != tt.Out {
				t.Errorf("incorrect output.\n")
				if !strings.HasPrefix(tt.Name, "testdata/") {
					t.Errorf("--- have\n%s\n--- want\n%s", out, tt.Out)
				}
				tdiff(t, "have", out, "want", tt.Out)
				return
			}

			if changed := out != tt.In; changed != fixed {
				t.Errorf("changed=%v != fixed=%v", changed, fixed)
				return
			}

			// Should not change if run again.
			out2, fixed2, ok := parseFixPrint(t, tt.Fn, tt.Name+" output", out, true)
			if !ok {
				return
			}

			if fixed2 {
				t.Errorf("applied fixes during second round")
				return
			}

			if out2 != out {
				t.Errorf("changed output after second round of fixes.\n--- output after first round\n%s\n--- output after second round\n%s",
					out, out2)
				tdiff(t, "first", out, "second", out2)
			}
		})
	}
}

func tdiff(t *testing.T, aname, a, bname, b string) {
	t.Errorf("%s", diff.Diff(aname, []byte(a), bname, []byte(b)))
}