tparallel

tparallel finds inappropriate usage of t.Parallel() method in your Go test codes.
It detects the following:

• t.Parallel() is called in either a top-level test function or a sub-test function only
• Although t.Parallel() is called in the sub-test function, it is post-processed by defer instead of t.Cleanup()

This tool was inspired by this blog: Test parallelization in Go: Understanding the t.Parallel() method

Installation

From GitHub Releases

Please see GitHub Releases.
Available binaries are:

• macOS
• Linux
• Windows

macOS

$ brew tap moricho/tparallel
$ brew install tparallel

go get

$ go get -u github.com/moricho/tparallel/cmd/tparallel

Usage

golangci-lint

golangci-lint now supports tparallel, so you can enable this linter and use in it.

shell

$ go vet -vettool=`which tparallel` <pkgname>

Example

package sample

import (
	"testing"
)

func Test_Table1(t *testing.T) {
	teardown := setup("Test_Table1")
	defer teardown()

	tests := []struct {
		name string
	}{
		{
			name: "Table1_Sub1",
		},
		{
			name: "Table1_Sub2",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()
			call(tt.name)
		})
	}
}

func Test_Table2(t *testing.T) {
	teardown := setup("Test_Table2")
	t.Cleanup(teardown)
	t.Parallel()

	tests := []struct {
		name string
	}{
		{
			name: "Table2_Sub1",
		},
		{
			name: "Table2_Sub2",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			call(tt.name)
		})
	}
}

# github.com/moricho/tparallel/testdata/src/sample
testdata/src/sample/table_test.go:7:6: Test_Table1 should use t.Cleanup
testdata/src/sample/table_test.go:7:6: Test_Table1 should call t.Parallel on the top level as well as its subtests
testdata/src/sample/table_test.go:30:6: Test_Table2's subtests should call t.Parallel