beforeEach and afterEach with go-test

before_after_each_test.go

package main

import (
	"fmt"
	"os"
	"runtime"
	"testing"
)

func TestMain(m *testing.M) {
	fmt.Println("Before All")
	m.Run()
	fmt.Println("After All")
	os.Exit(0)
}

// SetBeforeAndAfterEach takes before and after functions and returns a function called by t.Run().
func SetBeforeAndAfterEach(beforeFunc, afterFunc func(*testing.T)) func(func(*testing.T)) func(*testing.T) {
	return func(test func(*testing.T)) func(*testing.T) {
		return func(t *testing.T) {
			if beforeFunc != nil {
				beforeFunc(t)
			}
			test(t)
			if afterFunc != nil {
				afterFunc(t)
			}
		}
	}
}

// TestSetBeforeAndAfterEach show the usage example of SetBeforeAndAfterEach
func TestSetBeforeAndAfterEach(t *testing.T) {
	t.Logf("Test entered")
	defer t.Logf("Test exited")

	var nGoRoutine int

	run := SetBeforeAndAfterEach(
		func(t *testing.T) {
			t.Logf("Before %s", t.Name())
			nGoRoutine = runtime.NumGoroutine()
		},
		func(t *testing.T) {
			t.Logf("After %s (goroutines: %d => %d)", t.Name(), nGoRoutine, runtime.NumGoroutine())
		},
	)

	t.Run("subtest 1", run(func(t *testing.T) {
		defer t.Logf("Running %s", t.Name())
	}))

	t.Run("subtest 2", run(func(t *testing.T) {
		defer t.Logf("Running %s", t.Name())
	}))
}

% go test -v
Before All
=== RUN   TestSetBeforeAndAfterEach
    before_after_each_test.go:34: Test entered
=== RUN   TestSetBeforeAndAfterEach/subtest_1
    before_after_each_test.go:41: Before TestSetBeforeAndAfterEach/subtest_1
    before_after_each_test.go:51: Running TestSetBeforeAndAfterEach/subtest_1
    before_after_each_test.go:45: After TestSetBeforeAndAfterEach/subtest_1 (goroutines: 3 => 3)
=== RUN   TestSetBeforeAndAfterEach/subtest_2
    before_after_each_test.go:41: Before TestSetBeforeAndAfterEach/subtest_2
    before_after_each_test.go:55: Running TestSetBeforeAndAfterEach/subtest_2
    before_after_each_test.go:45: After TestSetBeforeAndAfterEach/subtest_2 (goroutines: 3 => 3)
=== CONT  TestSetBeforeAndAfterEach
    before_after_each_test.go:56: Test exited
--- PASS: TestSetBeforeAndAfterEach (0.00s)
    --- PASS: TestSetBeforeAndAfterEach/subtest_1 (0.00s)
    --- PASS: TestSetBeforeAndAfterEach/subtest_2 (0.00s)
PASS
After All