1[!fuzz] skip
2[short] skip
3env GOCACHE=$WORK/cache
4
5# There are no seed values, so 'go test' should finish quickly.
6go test
7
8# For the fuzzing phase, we reduce GOMAXPROCS to avoid consuming too many
9# resources during the test. Ideally this would just free up resources to run
10# other parallel tests more quickly, but unfortunately it is actually necessary
11# in some 32-bit environments to prevent the fuzzing engine from running out of
12# address space (see https://go.dev/issue/65434).
13env GOMAXPROCS=2
14
15# Fuzzing should exit 0 after fuzztime, even if timeout is short.
16go test -timeout=3s -fuzz=FuzzFast -fuzztime=5s
17
18# We should see the same behavior when invoking the test binary directly.
19go test -c
20exec ./fuzz.test$GOEXE -test.timeout=3s -test.fuzz=FuzzFast -test.fuzztime=5s -test.parallel=1 -test.fuzzcachedir=$WORK/cache
21
22# Timeout should not cause inputs to be written as crashers.
23! exists testdata/fuzz
24
25# When we use fuzztime with an "x" suffix, it runs a specific number of times.
26# This fuzz function creates a file with a unique name ($pid.$count) on each
27# run. We count the files to find the number of runs.
28mkdir count
29go test -fuzz=FuzzTestCount -fuzztime=1000x -fuzzminimizetime=1x
30go run check_file_count.go count 1000
31
32# When we use fuzzminimizetime with an "x" suffix, it runs a specific number of
33# times while minimizing. This fuzz function creates a file with a unique name
34# ($pid.$count) on each run once the first crash has been found. That means that
35# there should be one file for each execution of the fuzz function during
36# minimization, so we count these to determine how many times minimization was
37# run.
38mkdir minimizecount
39! go test -fuzz=FuzzMinimizeCount -fuzzminimizetime=3x -parallel=1
40go run check_file_count.go minimizecount 3
41
42-- go.mod --
43module fuzz
44
45go 1.16
46-- fuzz_fast_test.go --
47package fuzz_test
48
49import "testing"
50
51func FuzzFast(f *testing.F) {
52 f.Fuzz(func (*testing.T, []byte) {})
53}
54-- fuzz_count_test.go --
55package fuzz
56
57import (
58 "fmt"
59 "os"
60 "testing"
61)
62
63func FuzzTestCount(f *testing.F) {
64 pid := os.Getpid()
65 n := 0
66 f.Fuzz(func(t *testing.T, _ []byte) {
67 name := fmt.Sprintf("count/%v.%d", pid, n)
68 if err := os.WriteFile(name, nil, 0666); err != nil {
69 t.Fatal(err)
70 }
71 n++
72 })
73}
74-- fuzz_minimize_count_test.go --
75package fuzz
76
77import (
78 "bytes"
79 "fmt"
80 "os"
81 "testing"
82)
83
84func FuzzMinimizeCount(f *testing.F) {
85 pid := os.Getpid()
86 n := 0
87 seed := bytes.Repeat([]byte("a"), 357)
88 f.Add(seed)
89 crashFound := false
90 f.Fuzz(func(t *testing.T, b []byte) {
91 if crashFound {
92 name := fmt.Sprintf("minimizecount/%v.%d", pid, n)
93 if err := os.WriteFile(name, nil, 0666); err != nil {
94 t.Fatal(err)
95 }
96 n++
97 }
98 if !bytes.Equal(b, seed) { // this should happen right away
99 crashFound = true
100 t.Error("minimize this!")
101 }
102 })
103}
104-- check_file_count.go --
105// +build ignore
106
107package main
108
109import (
110 "fmt"
111 "os"
112 "strconv"
113)
114
115func main() {
116 dir, err := os.ReadDir(os.Args[1])
117 if err != nil {
118 fmt.Fprintln(os.Stderr, err)
119 os.Exit(1)
120 }
121 got := len(dir)
122 want, _ := strconv.Atoi(os.Args[2])
123 if got != want {
124 fmt.Fprintf(os.Stderr, "got %d files; want %d\n", got, want)
125 os.Exit(1)
126 }
127}
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