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