testing/slogtest: Parsing example fails when level is Error or Warn #62115
Description
What version of Go are you using (go version)?
$ go version go version go1.21.0 darwin/amd64
Does this issue reproduce with the latest release?
Yes
What operating system and processor architecture are you using (go env)?
go env Output
$ go env GO111MODULE='' GOARCH='amd64' GOBIN='' GOCACHE='/Users/varun/Library/Caches/go-build' GOENV='/Users/varun/Library/Application Support/go/env' GOEXE='' GOEXPERIMENT='' GOFLAGS='' GOHOSTARCH='amd64' GOHOSTOS='darwin' GOINSECURE='' GOMODCACHE='/Users/varun/go/pkg/mod' GONOPROXY='*.abc.com' GONOSUMDB='*.abc.com' GOOS='darwin' GOPATH='/Users/varun/go' GOPRIVATE='*.abc.com' GOPROXY='direct' GOROOT='/usr/local/go' GOSUMDB='sum.golang.org' GOTMPDIR='' GOTOOLCHAIN='auto' GOTOOLDIR='/usr/local/go/pkg/tool/darwin_amd64' GOVCS='' GOVERSION='go1.21.0' GCCGO='gccgo' GOAMD64='v1' AR='ar' CC='clang' CXX='clang++' CGO_ENABLED='1' GOMOD='/Users/varun/test/go.mod' GOWORK='' CGO_CFLAGS='-O2 -g' CGO_CPPFLAGS='' CGO_CXXFLAGS='-O2 -g' CGO_FFLAGS='-O2 -g' CGO_LDFLAGS='-O2 -g' PKG_CONFIG='pkg-config' GOGCCFLAGS='-fPIC -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/60/qpt9s9_s7lq9g9w7p53079nr0000gn/T/go-build3087313581=/tmp/go-build -gno-record-gcc-switches -fno-common'
What did you do?
Copied example from package docs, added a level and tried running it.
func TestCustomHandler(t *testing.T) {
var buf bytes.Buffer
h := slog.NewJSONHandler(&buf, &slog.HandlerOptions{
Level: slog.LevelError,
})
results := func() []map[string]any {
var ms []map[string]any
for _, line := range bytes.Split(buf.Bytes(), []byte{'\n'}) {
if len(line) == 0 {
continue
}
var m map[string]any
if err := json.Unmarshal(line, &m); err != nil {
t.Fatal(err)
}
ms = append(ms, m)
}
return ms
}
err := slogtest.TestHandler(h, results)
if err != nil {
t.Fatal(err)
}
}
What did you expect to see?
I expected to see the test pass.
What did you see instead?
--- FAIL: TestCustomHandler (0.00s)
/Users/varun/code/logger/multihandler_test.go:34: got 0 results, want 15
NOTE: Same test passes if Level is changed to Info or Debug.