src/testing/testing_test.go

// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package testing_test

import (
	"io/ioutil"
	"os"
	"testing"
)

// This is exactly what a test would do without a TestMain.
// It's here only so that there is at least one package in the
// standard library with a TestMain, so that code is executed.

func TestMain(m *testing.M) {
	os.Exit(m.Run())
}

func TestTempDir(t *testing.T) {
	testTempDir(t)
	t.Run("InSubtest", testTempDir)
	t.Run("test/subtest", testTempDir)
	t.Run("test\\subtest", testTempDir)
	t.Run("test:subtest", testTempDir)
	t.Run("test/..", testTempDir)
	t.Run("../test", testTempDir)
}

func testTempDir(t *testing.T) {
	dirCh := make(chan string, 1)
	t.Cleanup(func() {
		// Verify directory has been removed.
		select {
		case dir := <-dirCh:
			fi, err := os.Stat(dir)
			if os.IsNotExist(err) {
				// All good
				return
			}
			if err != nil {
				t.Fatal(err)
			}
			t.Errorf("directory %q stil exists: %v, isDir=%v", dir, fi, fi.IsDir())
		default:
			if !t.Failed() {
				t.Fatal("never received dir channel")
			}
		}
	})

	dir := t.TempDir()
	if dir == "" {
		t.Fatal("expected dir")
	}
	dir2 := t.TempDir()
	if dir != dir2 {
		t.Fatal("directory changed between calls")
	}
	dirCh <- dir
	fi, err := os.Stat(dir)
	if err != nil {
		t.Fatal(err)
	}
	if !fi.IsDir() {
		t.Errorf("dir %q is not a dir", dir)
	}
	fis, err := ioutil.ReadDir(dir)
	if err != nil {
		t.Fatal(err)
	}
	if len(fis) > 0 {
		t.Errorf("unexpected %d files in TempDir: %v", len(fis), fis)
	}
}