1// Copyright 2016 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 testdeps provides access to dependencies needed by test execution.
6//
7// This package is imported by the generated main package, which passes
8// TestDeps into testing.Main. This allows tests to use packages at run time
9// without making those packages direct dependencies of package testing.
10// Direct dependencies of package testing are harder to write tests for.
11package testdeps
12
13import (
14	"bufio"
15	"internal/testlog"
16	"io"
17	"regexp"
18	"runtime/pprof"
19	"strings"
20	"sync"
21)
22
23// TestDeps is an implementation of the testing.testDeps interface,
24// suitable for passing to testing.MainStart.
25type TestDeps struct{}
26
27var matchPat string
28var matchRe *regexp.Regexp
29
30func (TestDeps) MatchString(pat, str string) (result bool, err error) {
31	if matchRe == nil || matchPat != pat {
32		matchPat = pat
33		matchRe, err = regexp.Compile(matchPat)
34		if err != nil {
35			return
36		}
37	}
38	return matchRe.MatchString(str), nil
39}
40
41func (TestDeps) StartCPUProfile(w io.Writer) error {
42	return pprof.StartCPUProfile(w)
43}
44
45func (TestDeps) StopCPUProfile() {
46	pprof.StopCPUProfile()
47}
48
49func (TestDeps) WriteProfileTo(name string, w io.Writer, debug int) error {
50	return pprof.Lookup(name).WriteTo(w, debug)
51}
52
53// ImportPath is the import path of the testing binary, set by the generated main function.
54var ImportPath string
55
56func (TestDeps) ImportPath() string {
57	return ImportPath
58}
59
60// testLog implements testlog.Interface, logging actions by package os.
61type testLog struct {
62	mu  sync.Mutex
63	w   *bufio.Writer
64	set bool
65}
66
67func (l *testLog) Getenv(key string) {
68	l.add("getenv", key)
69}
70
71func (l *testLog) Open(name string) {
72	l.add("open", name)
73}
74
75func (l *testLog) Stat(name string) {
76	l.add("stat", name)
77}
78
79func (l *testLog) Chdir(name string) {
80	l.add("chdir", name)
81}
82
83// add adds the (op, name) pair to the test log.
84func (l *testLog) add(op, name string) {
85	if strings.Contains(name, "\n") || name == "" {
86		return
87	}
88
89	l.mu.Lock()
90	defer l.mu.Unlock()
91	if l.w == nil {
92		return
93	}
94	l.w.WriteString(op)
95	l.w.WriteByte(' ')
96	l.w.WriteString(name)
97	l.w.WriteByte('\n')
98}
99
100var log testLog
101
102func (TestDeps) StartTestLog(w io.Writer) {
103	log.mu.Lock()
104	log.w = bufio.NewWriter(w)
105	if !log.set {
106		// Tests that define TestMain and then run m.Run multiple times
107		// will call StartTestLog/StopTestLog multiple times.
108		// Checking log.set avoids calling testlog.SetLogger multiple times
109		// (which will panic) and also avoids writing the header multiple times.
110		log.set = true
111		testlog.SetLogger(&log)
112		log.w.WriteString("# test log\n") // known to cmd/go/internal/test/test.go
113	}
114	log.mu.Unlock()
115}
116
117func (TestDeps) StopTestLog() error {
118	log.mu.Lock()
119	defer log.mu.Unlock()
120	err := log.w.Flush()
121	log.w = nil
122	return err
123}
124