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| author | Bryan C. Mills <bcmills@google.com> | 2022-02-16 10:52:01 -0500 |
|---|---|---|
| committer | Bryan Mills <bcmills@google.com> | 2022-02-16 16:06:39 +0000 |
| commit | f985833dec19b0147db3c5c33d3bf0181891d458 (patch) | |
| tree | 73ea1d2b66e8867fc7efeb355a4f581ce1b4f2e4 | |
| parent | 5d8d3878496918d51347422d651629975343b18e (diff) | |
| download | go-f985833dec19b0147db3c5c33d3bf0181891d458.tar.gz go-f985833dec19b0147db3c5c33d3bf0181891d458.zip | |
testing: panic in Fuzz if the function returns a value
Otherwise, the behavior of a fuzz target that returns an error could
be confusing.
Fuzz is already documented to require a function “with no return
value”, so this fixes the implementation to match the existing
documentation.
Fixes #51222
Change-Id: I44ca7ee10960214c92f5ac066ac8484c8bb9cd6f
Reviewed-on: https://go-review.googlesource.com/c/go/+/386175
Trust: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Nooras Saba <saba@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
| -rw-r--r-- | src/cmd/go/testdata/script/test_fuzz_return.txt | 19 | ||||
| -rw-r--r-- | src/testing/fuzz.go | 3 |
2 files changed, 22 insertions, 0 deletions
diff --git a/src/cmd/go/testdata/script/test_fuzz_return.txt b/src/cmd/go/testdata/script/test_fuzz_return.txt new file mode 100644 index 0000000000..63275aad01 --- /dev/null +++ b/src/cmd/go/testdata/script/test_fuzz_return.txt @@ -0,0 +1,19 @@ +[short] skip + +! go test . +stdout '^panic: testing: fuzz target must not return a value \[recovered\]$' + +-- go.mod -- +module test +go 1.18 +-- x_test.go -- +package test + +import "testing" + +func FuzzReturnErr(f *testing.F) { + f.Add("hello, validation!") + f.Fuzz(func(t *testing.T, in string) string { + return in + }) +} diff --git a/src/testing/fuzz.go b/src/testing/fuzz.go index e1d7544f7a..b5e1339deb 100644 --- a/src/testing/fuzz.go +++ b/src/testing/fuzz.go @@ -227,6 +227,9 @@ func (f *F) Fuzz(ff any) { if fnType.NumIn() < 2 || fnType.In(0) != reflect.TypeOf((*T)(nil)) { panic("testing: fuzz target must receive at least two arguments, where the first argument is a *T") } + if fnType.NumOut() != 0 { + panic("testing: fuzz target must not return a value") + } // Save the types of the function to compare against the corpus. var types []reflect.Type |