testing: duplicate "pass" action from TestFlag/-test.v=test2json when run with go test -json #59181
Description
What version of Go are you using (go version)?
$ go version go version devel go1.21-ac881545ce Tue Mar 21 12:44:04 2023 -0400 darwin/arm64
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="arm64" GOBIN="" GOCACHE="/Users/dmitshur/Library/Caches/go-build" GOENV="/Users/dmitshur/Library/Application Support/go/env" GOEXE="" GOEXPERIMENT="" GOFLAGS="" GOHOSTARCH="arm64" GOHOSTOS="darwin" GOINSECURE="" GOMODCACHE="/Users/dmitshur/go/pkg/mod" GONOPROXY="" GONOSUMDB="" GOOS="darwin" GOPATH="/Users/dmitshur/go" GOPRIVATE="" GOPROXY="https://proxy.golang.org,direct" GOROOT="/Users/dmitshur/gotip" GOSUMDB="sum.golang.org" GOTMPDIR="" GOTOOLDIR="/Users/dmitshur/gotip/pkg/tool/darwin_arm64" GOVCS="" GOVERSION="devel go1.21-ac881545ce Tue Mar 21 12:44:04 2023 -0400" GCCGO="gccgo" AR="ar" CC="clang" CXX="clang++" CGO_ENABLED="1" GOMOD="/Users/dmitshur/gotip/src/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 arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/s_/5sjqzr0j6xggz_xtzmq_8r4m00jwcj/T/go-build2300515905=/tmp/go-build -gno-record-gcc-switches -fno-common"
What did you do?
When testing the entire standard library with -json flag, one of the tests produces a "pass" action event twice rather than the usual one time maximum.
This can be reproduced with:
go test -json -run='TestFlag' testing | grep '"Action":"pass","Package":"testing","Test":"TestFlag"' | wc -l
It also seems to reproduce if invoking the test binary and test2json manually:
go test -c testing -o /tmp/testing.test && /tmp/testing.test -test.run='TestFlag' -test.v=test2json | go tool test2json | grep '"Action":"pass","Test":"TestFlag"' | wc -l
What did you expect to see?
1
What did you see instead?
2
I'm not definitively sure that it is a bug for a pass action to be emitted more than once for the same package/test, but it seems unexpected. This came up from #37486, and out of all the packages and tests in the standard library, it happens only with this one.
As a quick investigation note, the 'TestFlag/-test.v=test2json' test in testing package (i.e., go test -v -run='TestFlag/-test.v=test2json' testing) seems to emit 0x16 bytes, which test2json also uses, and that may contribute to its confusion.
It seems like a minor issue given I haven't yet encountered any tools that this causes a serious problem in, and in tools one has control over it's easy to work around by ignoring it, but reporting it anyway.