os: replace os.MkdirTemp with T.TempDir

Updates #45402

Change-Id: Ib8e62a13ddff884e4d34b3a0fdc9a10db2b68da6
Reviewed-on: https://go-review.googlesource.com/c/go/+/308109
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>

8 files changed, 45 insertions, 175 deletions

diff --git a/src/os/error_test.go b/src/os/error_test.go
index 6264ccc966..58b3f391d1 100644
--- a/src/os/error_test.go
+++ b/src/os/error_test.go
@@ -54,13 +54,7 @@ func testErrNotExist(name string) string {
 }
 
 func TestErrIsNotExist(t *testing.T) {
-	tmpDir, err := os.MkdirTemp("", "_Go_ErrIsNotExist")
-	if err != nil {
-		t.Fatalf("create ErrIsNotExist tempdir: %s", err)
-		return
-	}
-	defer os.RemoveAll(tmpDir)
-
+	tmpDir := t.TempDir()
 	name := filepath.Join(tmpDir, "NotExists")
 	if s := testErrNotExist(name); s != "" {
 		t.Fatal(s)
diff --git a/src/os/fifo_test.go b/src/os/fifo_test.go
index c3607344ec..9b262f8205 100644
--- a/src/os/fifo_test.go
+++ b/src/os/fifo_test.go
@@ -31,12 +31,7 @@ func TestFifoEOF(t *testing.T) {
 		t.Skip("skipping on OpenBSD; issue 25877")
 	}
 
-	dir, err := os.MkdirTemp("", "TestFifoEOF")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(dir)
-
+	dir := t.TempDir()
 	fifoName := filepath.Join(dir, "fifo")
 	if err := syscall.Mkfifo(fifoName, 0600); err != nil {
 		t.Fatal(err)
diff --git a/src/os/os_test.go b/src/os/os_test.go
index f27c796c05..506f1fb0ee 100644
--- a/src/os/os_test.go
+++ b/src/os/os_test.go
@@ -617,11 +617,7 @@ func TestReaddirNValues(t *testing.T) {
 	if testing.Short() {
 		t.Skip("test.short; skipping")
 	}
-	dir, err := os.MkdirTemp("", "")
-	if err != nil {
-		t.Fatalf("TempDir: %v", err)
-	}
-	defer RemoveAll(dir)
+	dir := t.TempDir()
 	for i := 1; i <= 105; i++ {
 		f, err := Create(filepath.Join(dir, fmt.Sprintf("%d", i)))
 		if err != nil {
@@ -716,11 +712,7 @@ func TestReaddirStatFailures(t *testing.T) {
 		// testing it wouldn't work.
 		t.Skipf("skipping test on %v", runtime.GOOS)
 	}
-	dir, err := os.MkdirTemp("", "")
-	if err != nil {
-		t.Fatalf("TempDir: %v", err)
-	}
-	defer RemoveAll(dir)
+	dir := t.TempDir()
 	touch(t, filepath.Join(dir, "good1"))
 	touch(t, filepath.Join(dir, "x")) // will disappear or have an error
 	touch(t, filepath.Join(dir, "good2"))
@@ -1949,22 +1941,16 @@ func TestAppend(t *testing.T) {
 
 func TestStatDirWithTrailingSlash(t *testing.T) {
 	// Create new temporary directory and arrange to clean it up.
-	path, err := os.MkdirTemp("", "_TestStatDirWithSlash_")
-	if err != nil {
-		t.Fatalf("TempDir: %s", err)
-	}
-	defer RemoveAll(path)
+	path := t.TempDir()
 
 	// Stat of path should succeed.
-	_, err = Stat(path)
-	if err != nil {
+	if _, err := Stat(path); err != nil {
 		t.Fatalf("stat %s failed: %s", path, err)
 	}
 
 	// Stat of path+"/" should succeed too.
 	path += "/"
-	_, err = Stat(path)
-	if err != nil {
+	if _, err := Stat(path); err != nil {
 		t.Fatalf("stat %s failed: %s", path, err)
 	}
 }
@@ -2091,12 +2077,7 @@ func TestLargeWriteToConsole(t *testing.T) {
 func TestStatDirModeExec(t *testing.T) {
 	const mode = 0111
 
-	path, err := os.MkdirTemp("", "go-build")
-	if err != nil {
-		t.Fatalf("Failed to create temp directory: %v", err)
-	}
-	defer RemoveAll(path)
-
+	path := t.TempDir()
 	if err := Chmod(path, 0777); err != nil {
 		t.Fatalf("Chmod %q 0777: %v", path, err)
 	}
@@ -2160,12 +2141,7 @@ func TestStatStdin(t *testing.T) {
 func TestStatRelativeSymlink(t *testing.T) {
 	testenv.MustHaveSymlink(t)
 
-	tmpdir, err := os.MkdirTemp("", "TestStatRelativeSymlink")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer RemoveAll(tmpdir)
-
+	tmpdir := t.TempDir()
 	target := filepath.Join(tmpdir, "target")
 	f, err := Create(target)
 	if err != nil {
diff --git a/src/os/os_windows_test.go b/src/os/os_windows_test.go
index f310a75f39..195c30f50e 100644
--- a/src/os/os_windows_test.go
+++ b/src/os/os_windows_test.go
@@ -626,11 +626,7 @@ func TestOpenVolumeName(t *testing.T) {
 }
 
 func TestDeleteReadOnly(t *testing.T) {
-	tmpdir, err := os.MkdirTemp("", "TestDeleteReadOnly")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmpdir)
+	tmpdir := t.TempDir()
 	p := filepath.Join(tmpdir, "a")
 	// This sets FILE_ATTRIBUTE_READONLY.
 	f, err := os.OpenFile(p, os.O_CREATE, 0400)
@@ -796,11 +792,7 @@ func compareCommandLineToArgvWithSyscall(t *testing.T, cmd string) {
 }
 
 func TestCmdArgs(t *testing.T) {
-	tmpdir, err := os.MkdirTemp("", "TestCmdArgs")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmpdir)
+	tmpdir := t.TempDir()
 
 	const prog = `
 package main
@@ -815,8 +807,7 @@ func main() {
 }
 `
 	src := filepath.Join(tmpdir, "main.go")
-	err = os.WriteFile(src, []byte(prog), 0666)
-	if err != nil {
+	if err := os.WriteFile(src, []byte(prog), 0666); err != nil {
 		t.Fatal(err)
 	}
 
@@ -963,21 +954,14 @@ func TestSymlinkCreation(t *testing.T) {
 	}
 	t.Parallel()
 
-	temp, err := os.MkdirTemp("", "TestSymlinkCreation")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(temp)
-
+	temp := t.TempDir()
 	dummyFile := filepath.Join(temp, "file")
-	err = os.WriteFile(dummyFile, []byte(""), 0644)
-	if err != nil {
+	if err := os.WriteFile(dummyFile, []byte(""), 0644); err != nil {
 		t.Fatal(err)
 	}
 
 	linkFile := filepath.Join(temp, "link")
-	err = os.Symlink(dummyFile, linkFile)
-	if err != nil {
+	if err := os.Symlink(dummyFile, linkFile); err != nil {
 		t.Fatal(err)
 	}
 }
diff --git a/src/os/path_test.go b/src/os/path_test.go
index b79d958711..4535abbc52 100644
--- a/src/os/path_test.go
+++ b/src/os/path_test.go
@@ -6,7 +6,6 @@ package os_test
 
 import (
 	"internal/testenv"
-	"os"
 	. "os"
 	"path/filepath"
 	"runtime"
@@ -78,27 +77,19 @@ func TestMkdirAll(t *testing.T) {
 func TestMkdirAllWithSymlink(t *testing.T) {
 	testenv.MustHaveSymlink(t)
 
-	tmpDir, err := os.MkdirTemp("", "TestMkdirAllWithSymlink-")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer RemoveAll(tmpDir)
-
+	tmpDir := t.TempDir()
 	dir := tmpDir + "/dir"
-	err = Mkdir(dir, 0755)
-	if err != nil {
+	if err := Mkdir(dir, 0755); err != nil {
 		t.Fatalf("Mkdir %s: %s", dir, err)
 	}
 
 	link := tmpDir + "/link"
-	err = Symlink("dir", link)
-	if err != nil {
+	if err := Symlink("dir", link); err != nil {
 		t.Fatalf("Symlink %s: %s", link, err)
 	}
 
 	path := link + "/foo"
-	err = MkdirAll(path, 0755)
-	if err != nil {
+	if err := MkdirAll(path, 0755); err != nil {
 		t.Errorf("MkdirAll %q: %s", path, err)
 	}
 }
diff --git a/src/os/path_windows_test.go b/src/os/path_windows_test.go
index a23a079f77..e960bcb19c 100644
--- a/src/os/path_windows_test.go
+++ b/src/os/path_windows_test.go
@@ -50,31 +50,21 @@ func TestFixLongPath(t *testing.T) {
 }
 
 func TestMkdirAllLongPath(t *testing.T) {
-	tmpDir, err := os.MkdirTemp("", "TestMkdirAllLongPath")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmpDir)
+	tmpDir := t.TempDir()
 	path := tmpDir
 	for i := 0; i < 100; i++ {
 		path += `\another-path-component`
 	}
-	err = os.MkdirAll(path, 0777)
-	if err != nil {
+	if err := os.MkdirAll(path, 0777); err != nil {
 		t.Fatalf("MkdirAll(%q) failed; %v", path, err)
 	}
-	err = os.RemoveAll(tmpDir)
-	if err != nil {
+	if err := os.RemoveAll(tmpDir); err != nil {
 		t.Fatalf("RemoveAll(%q) failed; %v", tmpDir, err)
 	}
 }
 
 func TestMkdirAllExtendedLength(t *testing.T) {
-	tmpDir, err := os.MkdirTemp("", "TestMkdirAllExtendedLength")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmpDir)
+	tmpDir := t.TempDir()
 
 	const prefix = `\\?\`
 	if len(tmpDir) < 4 || tmpDir[:4] != prefix {
@@ -85,14 +75,12 @@ func TestMkdirAllExtendedLength(t *testing.T) {
 		tmpDir = prefix + fullPath
 	}
 	path := tmpDir + `\dir\`
-	err = os.MkdirAll(path, 0777)
-	if err != nil {
+	if err := os.MkdirAll(path, 0777); err != nil {
 		t.Fatalf("MkdirAll(%q) failed: %v", path, err)
 	}
 
 	path = path + `.\dir2`
-	err = os.MkdirAll(path, 0777)
-	if err == nil {
+	if err := os.MkdirAll(path, 0777); err == nil {
 		t.Fatalf("MkdirAll(%q) should have failed, but did not", path)
 	}
 }
diff --git a/src/os/removeall_test.go b/src/os/removeall_test.go
index 3a2f6e3759..08dfdd8ec0 100644
--- a/src/os/removeall_test.go
+++ b/src/os/removeall_test.go
@@ -15,12 +15,7 @@ import (
 )
 
 func TestRemoveAll(t *testing.T) {
-	tmpDir, err := os.MkdirTemp("", "TestRemoveAll-")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer RemoveAll(tmpDir)
-
+	tmpDir := t.TempDir()
 	if err := RemoveAll(""); err != nil {
 		t.Errorf("RemoveAll(\"\"): %v; want nil", err)
 	}
@@ -128,12 +123,7 @@ func TestRemoveAllLarge(t *testing.T) {
 		t.Skip("skipping in short mode")
 	}
 
-	tmpDir, err := os.MkdirTemp("", "TestRemoveAll-")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer RemoveAll(tmpDir)
-
+	tmpDir := t.TempDir()
 	path := filepath.Join(tmpDir, "_TestRemoveAllLarge_")
 
 	// Make directory with 1000 files and remove.
@@ -236,12 +226,7 @@ func TestRemoveAllDot(t *testing.T) {
 func TestRemoveAllDotDot(t *testing.T) {
 	t.Parallel()
 
-	tempDir, err := os.MkdirTemp("", "TestRemoveAllDotDot-")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer RemoveAll(tempDir)
-
+	tempDir := t.TempDir()
 	subdir := filepath.Join(tempDir, "x")
 	subsubdir := filepath.Join(subdir, "y")
 	if err := MkdirAll(subsubdir, 0777); err != nil {
@@ -261,12 +246,7 @@ func TestRemoveAllDotDot(t *testing.T) {
 func TestRemoveReadOnlyDir(t *testing.T) {
 	t.Parallel()
 
-	tempDir, err := os.MkdirTemp("", "TestRemoveReadOnlyDir-")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer RemoveAll(tempDir)
-
+	tempDir := t.TempDir()
 	subdir := filepath.Join(tempDir, "x")
 	if err := Mkdir(subdir, 0); err != nil {
 		t.Fatal(err)
@@ -298,12 +278,7 @@ func TestRemoveAllButReadOnlyAndPathError(t *testing.T) {
 
 	t.Parallel()
 
-	tempDir, err := os.MkdirTemp("", "TestRemoveAllButReadOnly-")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer RemoveAll(tempDir)
-
+	tempDir := t.TempDir()
 	dirs := []string{
 		"a",
 		"a/x",
@@ -347,7 +322,7 @@ func TestRemoveAllButReadOnlyAndPathError(t *testing.T) {
 		defer Chmod(d, 0777)
 	}
 
-	err = RemoveAll(tempDir)
+	err := RemoveAll(tempDir)
 	if err == nil {
 		t.Fatal("RemoveAll succeeded unexpectedly")
 	}
@@ -389,12 +364,7 @@ func TestRemoveUnreadableDir(t *testing.T) {
 
 	t.Parallel()
 
-	tempDir, err := os.MkdirTemp("", "TestRemoveAllButReadOnly-")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer RemoveAll(tempDir)
-
+	tempDir := t.TempDir()
 	target := filepath.Join(tempDir, "d0", "d1", "d2")
 	if err := MkdirAll(target, 0755); err != nil {
 		t.Fatal(err)
@@ -413,12 +383,7 @@ func TestRemoveAllWithMoreErrorThanReqSize(t *testing.T) {
 		t.Skip("skipping in short mode")
 	}
 
-	tmpDir, err := os.MkdirTemp("", "TestRemoveAll-")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer RemoveAll(tmpDir)
-
+	tmpDir := t.TempDir()
 	path := filepath.Join(tmpDir, "_TestRemoveAllWithMoreErrorThanReqSize_")
 
 	// Make directory with 1025 read-only files.
@@ -443,7 +408,7 @@ func TestRemoveAllWithMoreErrorThanReqSize(t *testing.T) {
 
 	// This call should not hang, even on a platform that disallows file deletion
 	// from read-only directories.
-	err = RemoveAll(path)
+	err := RemoveAll(path)
 
 	if Getuid() == 0 {
 		// On many platforms, root can remove files from read-only directories.
diff --git a/src/os/stat_test.go b/src/os/stat_test.go
index c409f0ff18..8d99f64609 100644
--- a/src/os/stat_test.go
+++ b/src/os/stat_test.go
@@ -185,30 +185,22 @@ func testSymlinkSameFile(t *testing.T, path, link string) {
 func TestDirAndSymlinkStats(t *testing.T) {
 	testenv.MustHaveSymlink(t)
 
-	tmpdir, err := os.MkdirTemp("", "TestDirAndSymlinkStats")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmpdir)
-
+	tmpdir := t.TempDir()
 	dir := filepath.Join(tmpdir, "dir")
-	err = os.Mkdir(dir, 0777)
-	if err != nil {
+	if err := os.Mkdir(dir, 0777); err != nil {
 		t.Fatal(err)
 	}
 	testDirStats(t, dir)
 
 	dirlink := filepath.Join(tmpdir, "link")
-	err = os.Symlink(dir, dirlink)
-	if err != nil {
+	if err := os.Symlink(dir, dirlink); err != nil {
 		t.Fatal(err)
 	}
 	testSymlinkStats(t, dirlink, true)
 	testSymlinkSameFile(t, dir, dirlink)
 
 	linklink := filepath.Join(tmpdir, "linklink")
-	err = os.Symlink(dirlink, linklink)
-	if err != nil {
+	if err := os.Symlink(dirlink, linklink); err != nil {
 		t.Fatal(err)
 	}
 	testSymlinkStats(t, linklink, true)
@@ -218,30 +210,22 @@ func TestDirAndSymlinkStats(t *testing.T) {
 func TestFileAndSymlinkStats(t *testing.T) {
 	testenv.MustHaveSymlink(t)
 
-	tmpdir, err := os.MkdirTemp("", "TestFileAndSymlinkStats")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmpdir)
-
+	tmpdir := t.TempDir()
 	file := filepath.Join(tmpdir, "file")
-	err = os.WriteFile(file, []byte(""), 0644)
-	if err != nil {
+	if err := os.WriteFile(file, []byte(""), 0644); err != nil {
 		t.Fatal(err)
 	}
 	testFileStats(t, file)
 
 	filelink := filepath.Join(tmpdir, "link")
-	err = os.Symlink(file, filelink)
-	if err != nil {
+	if err := os.Symlink(file, filelink); err != nil {
 		t.Fatal(err)
 	}
 	testSymlinkStats(t, filelink, false)
 	testSymlinkSameFile(t, file, filelink)
 
 	linklink := filepath.Join(tmpdir, "linklink")
-	err = os.Symlink(filelink, linklink)
-	if err != nil {
+	if err := os.Symlink(filelink, linklink); err != nil {
 		t.Fatal(err)
 	}
 	testSymlinkStats(t, linklink, false)
@@ -252,20 +236,13 @@ func TestFileAndSymlinkStats(t *testing.T) {
 func TestSymlinkWithTrailingSlash(t *testing.T) {
 	testenv.MustHaveSymlink(t)
 
-	tmpdir, err := os.MkdirTemp("", "TestSymlinkWithTrailingSlash")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(tmpdir)
-
+	tmpdir := t.TempDir()
 	dir := filepath.Join(tmpdir, "dir")
-	err = os.Mkdir(dir, 0777)
-	if err != nil {
+	if err := os.Mkdir(dir, 0777); err != nil {
 		t.Fatal(err)
 	}
 	dirlink := filepath.Join(tmpdir, "link")
-	err = os.Symlink(dir, dirlink)
-	if err != nil {
+	if err := os.Symlink(dir, dirlink); err != nil {
 		t.Fatal(err)
 	}
 	dirlinkWithSlash := dirlink + string(os.PathSeparator)