cmd/test2json: adding an fmt.Print in tests skip the pass action in json output

[ebriney]

What version of Go are you using (go version)?

$ go version
go version go1.17.1 darwin/arm64

Does this issue reproduce with the latest release?

Yes. It's the same on 1.17.3

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""
GOARCH="arm64"
GOBIN=""
GOCACHE="/Users/emmanuelbriney/Library/Caches/go-build"
GOENV="/Users/emmanuelbriney/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="arm64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/emmanuelbriney/go/pkg/mod"
GONOPROXY="github.com/docker,github.com/<...>"
GONOSUMDB="github.com/docker,github.com/<...>"
GOOS="darwin"
GOPATH="/Users/emmanuelbriney/go"
GOPRIVATE="github.com/docker,github.com/<...>"
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_arm64"
GOVCS=""
GOVERSION="go1.17.1"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/Users/emmanuelbriney/prog/gotestbug/go.mod"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/09/qs9jt6q90j188bgbjb6ls36w0000gn/T/go-build1058730670=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

This simple test file illustrates it

package main

import (
	"fmt"
	"testing"
)

func TestWithFmt(t *testing.T) {
	fmt.Print("it fails")
}

func TestWithoutFmt(t *testing.T) {
}

When I use json output there is a missing event

go test -json
{"Time":"2021-11-17T11:57:51.123274+01:00","Action":"run","Package":"gotestbug","Test":"TestWithFmt"}
{"Time":"2021-11-17T11:57:51.123416+01:00","Action":"output","Package":"gotestbug","Test":"TestWithFmt","Output":"=== RUN   TestWithFmt\n"}
{"Time":"2021-11-17T11:57:51.123423+01:00","Action":"output","Package":"gotestbug","Test":"TestWithFmt","Output":"it fails--- PASS: TestWithFmt (0.00s)\n"}
{"Time":"2021-11-17T11:57:51.123427+01:00","Action":"run","Package":"gotestbug","Test":"TestWithoutFmt"}
{"Time":"2021-11-17T11:57:51.123429+01:00","Action":"output","Package":"gotestbug","Test":"TestWithoutFmt","Output":"=== RUN   TestWithoutFmt\n"}
{"Time":"2021-11-17T11:57:51.123435+01:00","Action":"output","Package":"gotestbug","Test":"TestWithoutFmt","Output":"--- PASS: TestWithoutFmt (0.00s)\n"}
{"Time":"2021-11-17T11:57:51.123437+01:00","Action":"pass","Package":"gotestbug","Test":"TestWithoutFmt","Elapsed":0}
{"Time":"2021-11-17T11:57:51.123441+01:00","Action":"output","Package":"gotestbug","Output":"PASS\n"}
{"Time":"2021-11-17T11:57:51.123471+01:00","Action":"output","Package":"gotestbug","Output":"ok  \tgotestbug\t0.003s\n"}
{"Time":"2021-11-17T11:57:51.123474+01:00","Action":"pass","Package":"gotestbug","Elapsed":0.003}

It's problematic because we can't state if the test passed or not.
Some tools like gotestsum considers it as failure because of this missing event.

What did you expect to see?

I should receive this event

 {"Time":"2021-11-17T11:57:51.123437+01:00","Action":"pass","Package":"gotestbug","Test":"TestWithFmt","Elapsed":0}

What did you see instead?

It's not emitted because I've added an fmt.Print

[seankhliao]

Duplicate of #26325