[dev.fuzz] testing: allow -fuzzminimizetime to be 0

Fixes #48321

Change-Id: I1547379eb7a703f7f3c4594d27833eb3587796a0
Reviewed-on: https://go-review.googlesource.com/c/go/+/349089
Trust: Katie Hockman <[email protected]>
Run-TryBot: Katie Hockman <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Jay Conrod <[email protected]>

Author: katiehockman

src/cmd/go/testdata/script/test_fuzz_minimize.txt

@@ -6,6 +6,32 @@
 # We clean the fuzz cache during this test. Don't clean the user's cache.
 env GOCACHE=$WORK/gocache
 
+# Test that fuzzminimizetime can be zero seconds
+! go test -fuzz=FuzzMinimizerRecoverable -run=FuzzMinimizerRecoverable -fuzztime=10000x -fuzzminimizetime=0s minimizer_test.go
+! stdout '^ok'
+stdout 'contains a non-zero byte'
+stdout FAIL
+
+# Test that fuzzminimizetime can be zero times
+! go test -fuzz=FuzzMinimizerRecoverable -run=FuzzMinimizerRecoverable -fuzztime=10000x -fuzzminimizetime=0x minimizer_test.go
+! stdout '^ok'
+stdout 'contains a non-zero byte'
+stdout FAIL
+
+# Test that fuzzminimizetime cannot be negative seconds
+! go test -fuzz=FuzzMinimizerRecoverable -run=FuzzMinimizerRecoverable -fuzztime=10000x -fuzzminimizetime=-1ms minimizer_test.go
+! stdout '^ok'
+! stdout 'contains a non-zero byte'
+stdout 'invalid duration'
+stdout FAIL
+
+# Test that fuzzminimizetime cannot be negative times
+! go test -fuzz=FuzzMinimizerRecoverable -run=FuzzMinimizerRecoverable -fuzztime=10000x -fuzzminimizetime=-1x minimizer_test.go
+! stdout '^ok'
+! stdout 'contains a non-zero byte'
+stdout 'invalid count'
+stdout FAIL
+
 # Test that minimization is working for recoverable errors.
 ! go test -fuzz=FuzzMinimizerRecoverable -run=FuzzMinimizerRecoverable -fuzztime=10000x minimizer_test.go
 ! stdout '^ok'

src/testing/benchmark.go

@@ -36,8 +36,9 @@ var (
 )
 
 type durationOrCountFlag struct {
-	d time.Duration
-	n int
+	d         time.Duration
+	n         int
+	allowZero bool
 }
 
 func (f *durationOrCountFlag) String() string {
@@ -50,14 +51,14 @@ func (f *durationOrCountFlag) String() string {
 func (f *durationOrCountFlag) Set(s string) error {
 	if strings.HasSuffix(s, "x") {
 		n, err := strconv.ParseInt(s[:len(s)-1], 10, 0)
-		if err != nil || n <= 0 {
+		if err != nil || n < 0 || (!f.allowZero && n == 0) {
 			return fmt.Errorf("invalid count")
 		}
 		*f = durationOrCountFlag{n: int(n)}
 		return nil
 	}
 	d, err := time.ParseDuration(s)
-	if err != nil || d <= 0 {
+	if err != nil || d < 0 || (!f.allowZero && d == 0) {
 		return fmt.Errorf("invalid duration")
 	}
 	*f = durationOrCountFlag{d: d}

src/testing/fuzz.go

@@ -28,7 +28,7 @@ func initFuzzFlags() {
 var (
 	matchFuzz        *string
 	fuzzDuration     durationOrCountFlag
-	minimizeDuration = durationOrCountFlag{d: 60 * time.Second}
+	minimizeDuration = durationOrCountFlag{d: 60 * time.Second, allowZero: true}
 	fuzzCacheDir     *string
 	isFuzzWorker     *bool