test: use `T.TempDir` to create temporary test directory (#21043)

A testing cleanup. 

This pull request replaces `os.MkdirTemp` with `t.TempDir`. We can use the `T.TempDir` function from the `testing` package to create temporary directory. The directory created by `T.TempDir` is automatically removed when the test and all its subtests complete. 

This saves us at least 2 lines (error check, and cleanup) on every instance, or in some cases adds cleanup that we forgot.

Reference: https://pkg.go.dev/testing#T.TempDir

```go
func TestFoo(t *testing.T) {
	// before
	tmpDir, err := os.MkdirTemp("", "")
	require.NoError(t, err)
	defer os.RemoveAll(tmpDir)

	// now
	tmpDir := t.TempDir()
}
```

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

11 files changed, 32 insertions, 89 deletions

diff --git a/tests/integration/api_repo_file_get_test.go b/tests/integration/api_repo_file_get_test.go
index 2a7a5fa634..cca72c2b3e 100644
--- a/tests/integration/api_repo_file_get_test.go
+++ b/tests/integration/api_repo_file_get_test.go
@@ -7,11 +7,9 @@ package integration
 import (
 	"net/http"
 	"net/url"
-	"os"
 	"testing"
 
 	api "code.gitea.io/gitea/modules/structs"
-	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/tests"
 
 	"github.com/stretchr/testify/assert"
@@ -30,18 +28,14 @@ func TestAPIGetRawFileOrLFS(t *testing.T) {
 		httpContext := NewAPITestContext(t, "user2", "repo-lfs-test")
 		doAPICreateRepository(httpContext, false, func(t *testing.T, repository api.Repository) {
 			u.Path = httpContext.GitPath()
-			dstPath, err := os.MkdirTemp("", httpContext.Reponame)
-			assert.NoError(t, err)
-			defer util.RemoveAll(dstPath)
+			dstPath := t.TempDir()
 
 			u.Path = httpContext.GitPath()
 			u.User = url.UserPassword("user2", userPassword)
 
 			t.Run("Clone", doGitClone(dstPath, u))
 
-			dstPath2, err := os.MkdirTemp("", httpContext.Reponame)
-			assert.NoError(t, err)
-			defer util.RemoveAll(dstPath2)
+			dstPath2 := t.TempDir()
 
 			t.Run("Partial Clone", doPartialGitClone(dstPath2, u))
 
diff --git a/tests/integration/api_repo_test.go b/tests/integration/api_repo_test.go
index 483503ccbb..bfe0c0aa9c 100644
--- a/tests/integration/api_repo_test.go
+++ b/tests/integration/api_repo_test.go
@@ -8,7 +8,6 @@ import (
 	"fmt"
 	"net/http"
 	"net/url"
-	"os"
 	"testing"
 
 	"code.gitea.io/gitea/models"
@@ -19,7 +18,6 @@ import (
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
-	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/tests"
 
 	"github.com/stretchr/testify/assert"
@@ -389,9 +387,6 @@ func testAPIRepoMigrateConflict(t *testing.T, u *url.URL) {
 		httpContext := baseAPITestContext
 
 		httpContext.Reponame = "repo-tmp-17"
-		dstPath, err := os.MkdirTemp("", httpContext.Reponame)
-		assert.NoError(t, err)
-		defer util.RemoveAll(dstPath)
 		t.Run("CreateRepo", doAPICreateRepository(httpContext, false))
 
 		user, err := user_model.GetUserByName(db.DefaultContext, httpContext.Username)
@@ -473,9 +468,6 @@ func testAPIRepoCreateConflict(t *testing.T, u *url.URL) {
 		httpContext := baseAPITestContext
 
 		httpContext.Reponame = "repo-tmp-17"
-		dstPath, err := os.MkdirTemp("", httpContext.Reponame)
-		assert.NoError(t, err)
-		defer util.RemoveAll(dstPath)
 		t.Run("CreateRepo", doAPICreateRepository(httpContext, false))
 
 		req := NewRequestWithJSON(t, "POST", "/api/v1/user/repos?token="+httpContext.Token,
diff --git a/tests/integration/create_no_session_test.go b/tests/integration/create_no_session_test.go
index c9b90974d7..c617b1828a 100644
--- a/tests/integration/create_no_session_test.go
+++ b/tests/integration/create_no_session_test.go
@@ -14,7 +14,6 @@ import (
 
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/setting"
-	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/routers"
 	"code.gitea.io/gitea/tests"
 
@@ -70,13 +69,7 @@ func TestSessionFileCreation(t *testing.T) {
 	config.Provider = "file"
 
 	// Now create a temporaryDirectory
-	tmpDir, err := os.MkdirTemp("", "sessions")
-	assert.NoError(t, err)
-	defer func() {
-		if _, err := os.Stat(tmpDir); !os.IsNotExist(err) {
-			_ = util.RemoveAll(tmpDir)
-		}
-	}()
+	tmpDir := t.TempDir()
 	config.ProviderConfig = tmpDir
 
 	newConfigBytes, err := json.Marshal(config)
diff --git a/tests/integration/git_clone_wiki_test.go b/tests/integration/git_clone_wiki_test.go
index 4bdbc9b7c3..3e10b17d40 100644
--- a/tests/integration/git_clone_wiki_test.go
+++ b/tests/integration/git_clone_wiki_test.go
@@ -35,8 +35,7 @@ func TestRepoCloneWiki(t *testing.T) {
 	onGiteaRun(t, func(t *testing.T, u *url.URL) {
 		defer tests.PrepareTestEnv(t)()
 
-		dstPath, err := os.MkdirTemp("", "clone_wiki")
-		assert.NoError(t, err)
+		dstPath := t.TempDir()
 
 		r := fmt.Sprintf("%suser2/repo1.wiki.git", u.String())
 		u, _ = url.Parse(r)
diff --git a/tests/integration/git_helper_for_declarative_test.go b/tests/integration/git_helper_for_declarative_test.go
index 666f9f6fe9..4f2e540883 100644
--- a/tests/integration/git_helper_for_declarative_test.go
+++ b/tests/integration/git_helper_for_declarative_test.go
@@ -27,11 +27,9 @@ import (
 )
 
 func withKeyFile(t *testing.T, keyname string, callback func(string)) {
-	tmpDir, err := os.MkdirTemp("", "key-file")
-	assert.NoError(t, err)
-	defer util.RemoveAll(tmpDir)
+	tmpDir := t.TempDir()
 
-	err = os.Chmod(tmpDir, 0o700)
+	err := os.Chmod(tmpDir, 0o700)
 	assert.NoError(t, err)
 
 	keyFile := filepath.Join(tmpDir, keyname)
@@ -120,9 +118,7 @@ func doPartialGitClone(dstLocalPath string, u *url.URL) func(*testing.T) {
 
 func doGitCloneFail(u *url.URL) func(*testing.T) {
 	return func(t *testing.T) {
-		tmpDir, err := os.MkdirTemp("", "doGitCloneFail")
-		assert.NoError(t, err)
-		defer util.RemoveAll(tmpDir)
+		tmpDir := t.TempDir()
 		assert.Error(t, git.Clone(git.DefaultContext, u.String(), tmpDir, git.CloneRepoOptions{}))
 		exist, err := util.IsExist(filepath.Join(tmpDir, "README.md"))
 		assert.NoError(t, err)
diff --git a/tests/integration/git_test.go b/tests/integration/git_test.go
index caeb5db8b3..bf5e809dab 100644
--- a/tests/integration/git_test.go
+++ b/tests/integration/git_test.go
@@ -27,7 +27,6 @@ import (
 	"code.gitea.io/gitea/modules/lfs"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
-	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/tests"
 
 	"github.com/stretchr/testify/assert"
@@ -57,9 +56,7 @@ func testGit(t *testing.T, u *url.URL) {
 		httpContext.Reponame = "repo-tmp-17"
 		forkedUserCtx.Reponame = httpContext.Reponame
 
-		dstPath, err := os.MkdirTemp("", httpContext.Reponame)
-		assert.NoError(t, err)
-		defer util.RemoveAll(dstPath)
+		dstPath := t.TempDir()
 
 		t.Run("CreateRepoInDifferentUser", doAPICreateRepository(forkedUserCtx, false))
 		t.Run("AddUserAsCollaborator", doAPIAddCollaborator(forkedUserCtx, httpContext.Username, perm.AccessModeRead))
@@ -71,9 +68,7 @@ func testGit(t *testing.T, u *url.URL) {
 
 		t.Run("Clone", doGitClone(dstPath, u))
 
-		dstPath2, err := os.MkdirTemp("", httpContext.Reponame)
-		assert.NoError(t, err)
-		defer util.RemoveAll(dstPath2)
+		dstPath2 := t.TempDir()
 
 		t.Run("Partial Clone", doPartialGitClone(dstPath2, u))
 
@@ -114,9 +109,7 @@ func testGit(t *testing.T, u *url.URL) {
 			sshURL := createSSHUrl(sshContext.GitPath(), u)
 
 			// Setup clone folder
-			dstPath, err := os.MkdirTemp("", sshContext.Reponame)
-			assert.NoError(t, err)
-			defer util.RemoveAll(dstPath)
+			dstPath := t.TempDir()
 
 			t.Run("Clone", doGitClone(dstPath, sshURL))
 
@@ -140,9 +133,7 @@ func testGit(t *testing.T, u *url.URL) {
 }
 
 func ensureAnonymousClone(t *testing.T, u *url.URL) {
-	dstLocalPath, err := os.MkdirTemp("", "repo1")
-	assert.NoError(t, err)
-	defer util.RemoveAll(dstLocalPath)
+	dstLocalPath := t.TempDir()
 	t.Run("CloneAnonymous", doGitClone(dstLocalPath, u))
 }
 
@@ -560,9 +551,7 @@ func doPushCreate(ctx APITestContext, u *url.URL) func(t *testing.T) {
 		u.Path = ctx.GitPath()
 
 		// Create a temporary directory
-		tmpDir, err := os.MkdirTemp("", ctx.Reponame)
-		assert.NoError(t, err)
-		defer util.RemoveAll(tmpDir)
+		tmpDir := t.TempDir()
 
 		// Now create local repository to push as our test and set its origin
 		t.Run("InitTestRepository", doGitInitTestRepository(tmpDir))
diff --git a/tests/integration/gpg_git_test.go b/tests/integration/gpg_git_test.go
index 2e16d150c8..80f484926d 100644
--- a/tests/integration/gpg_git_test.go
+++ b/tests/integration/gpg_git_test.go
@@ -16,7 +16,6 @@ import (
 	"code.gitea.io/gitea/modules/process"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
-	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/tests"
 
 	"github.com/stretchr/testify/assert"
@@ -29,11 +28,9 @@ func TestGPGGit(t *testing.T) {
 	username := "user2"
 
 	// OK Set a new GPG home
-	tmpDir, err := os.MkdirTemp("", "temp-gpg")
-	assert.NoError(t, err)
-	defer util.RemoveAll(tmpDir)
+	tmpDir := t.TempDir()
 
-	err = os.Chmod(tmpDir, 0o700)
+	err := os.Chmod(tmpDir, 0o700)
 	assert.NoError(t, err)
 
 	oldGNUPGHome := os.Getenv("GNUPGHOME")
diff --git a/tests/integration/lfs_local_endpoint_test.go b/tests/integration/lfs_local_endpoint_test.go
index 88c08c63db..4042dc95b3 100644
--- a/tests/integration/lfs_local_endpoint_test.go
+++ b/tests/integration/lfs_local_endpoint_test.go
@@ -25,15 +25,12 @@ func str2url(raw string) *url.URL {
 func TestDetermineLocalEndpoint(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 
-	root, _ := os.MkdirTemp("", "lfs_test")
-	defer os.RemoveAll(root)
+	root := t.TempDir()
 
-	rootdotgit, _ := os.MkdirTemp("", "lfs_test")
-	defer os.RemoveAll(rootdotgit)
+	rootdotgit := t.TempDir()
 	os.Mkdir(filepath.Join(rootdotgit, ".git"), 0o700)
 
-	lfsroot, _ := os.MkdirTemp("", "lfs_test")
-	defer os.RemoveAll(lfsroot)
+	lfsroot := t.TempDir()
 
 	// Test cases
 	cases := []struct {
diff --git a/tests/integration/migrate_test.go b/tests/integration/migrate_test.go
index 0fe4014344..99d5d6c8dd 100644
--- a/tests/integration/migrate_test.go
+++ b/tests/integration/migrate_test.go
@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"path/filepath"
 	"testing"
 
 	repo_model "code.gitea.io/gitea/models/repo"
@@ -29,16 +30,18 @@ func TestMigrateLocalPath(t *testing.T) {
 	old := setting.ImportLocalPaths
 	setting.ImportLocalPaths = true
 
-	lowercasePath, err := os.MkdirTemp("", "lowercase") // may not be lowercase because MkdirTemp creates a random directory name which may be mixedcase
+	basePath := t.TempDir()
+
+	lowercasePath := filepath.Join(basePath, "lowercase")
+	err := os.Mkdir(lowercasePath, 0o700)
 	assert.NoError(t, err)
-	defer os.RemoveAll(lowercasePath)
 
 	err = migrations.IsMigrateURLAllowed(lowercasePath, adminUser)
 	assert.NoError(t, err, "case lowercase path")
 
-	mixedcasePath, err := os.MkdirTemp("", "mIxeDCaSe")
+	mixedcasePath := filepath.Join(basePath, "mIxeDCaSe")
+	err = os.Mkdir(mixedcasePath, 0o700)
 	assert.NoError(t, err)
-	defer os.RemoveAll(mixedcasePath)
 
 	err = migrations.IsMigrateURLAllowed(mixedcasePath, adminUser)
 	assert.NoError(t, err, "case mixedcase path")
diff --git a/tests/integration/repo_tag_test.go b/tests/integration/repo_tag_test.go
index a91f1fb209..fb08895e21 100644
--- a/tests/integration/repo_tag_test.go
+++ b/tests/integration/repo_tag_test.go
@@ -6,7 +6,6 @@ package integration
 
 import (
 	"net/url"
-	"os"
 	"testing"
 
 	"code.gitea.io/gitea/models"
@@ -15,7 +14,6 @@ import (
 	"code.gitea.io/gitea/models/unittest"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/git"
-	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/services/release"
 	"code.gitea.io/gitea/tests"
 
@@ -59,16 +57,14 @@ func TestCreateNewTagProtected(t *testing.T) {
 			username := "user2"
 			httpContext := NewAPITestContext(t, username, "repo1")
 
-			dstPath, err := os.MkdirTemp("", httpContext.Reponame)
-			assert.NoError(t, err)
-			defer util.RemoveAll(dstPath)
+			dstPath := t.TempDir()
 
 			u.Path = httpContext.GitPath()
 			u.User = url.UserPassword(username, userPassword)
 
 			doGitClone(dstPath, u)(t)
 
-			_, _, err = git.NewCommand(git.DefaultContext, "tag", "v-2").RunStdString(&git.RunOpts{Dir: dstPath})
+			_, _, err := git.NewCommand(git.DefaultContext, "tag", "v-2").RunStdString(&git.RunOpts{Dir: dstPath})
 			assert.NoError(t, err)
 
 			_, _, err = git.NewCommand(git.DefaultContext, "push", "--tags").RunStdString(&git.RunOpts{Dir: dstPath})
diff --git a/tests/integration/ssh_key_test.go b/tests/integration/ssh_key_test.go
index 65d9b84404..fd98af5125 100644
--- a/tests/integration/ssh_key_test.go
+++ b/tests/integration/ssh_key_test.go
@@ -15,7 +15,6 @@ import (
 
 	"code.gitea.io/gitea/modules/git"
 	api "code.gitea.io/gitea/modules/structs"
-	"code.gitea.io/gitea/modules/util"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -61,9 +60,7 @@ func testPushDeployKeyOnEmptyRepo(t *testing.T, u *url.URL) {
 		t.Run("CreatePushDeployKey", doAPICreateDeployKey(ctx, keyname, keyFile, false))
 
 		// Setup the testing repository
-		dstPath, err := os.MkdirTemp("", "repo-tmp-deploy-key-empty-repo-1")
-		assert.NoError(t, err)
-		defer util.RemoveAll(dstPath)
+		dstPath := t.TempDir()
 
 		t.Run("InitTestRepository", doGitInitTestRepository(dstPath))
 
@@ -107,9 +104,7 @@ func testKeyOnlyOneType(t *testing.T, u *url.URL) {
 	withKeyFile(t, keyname, func(keyFile string) {
 		var userKeyPublicKeyID int64
 		t.Run("KeyCanOnlyBeUser", func(t *testing.T) {
-			dstPath, err := os.MkdirTemp("", ctx.Reponame)
-			assert.NoError(t, err)
-			defer util.RemoveAll(dstPath)
+			dstPath := t.TempDir()
 
 			sshURL := createSSHUrl(ctx.GitPath(), u)
 
@@ -133,9 +128,7 @@ func testKeyOnlyOneType(t *testing.T, u *url.URL) {
 		})
 
 		t.Run("KeyCanBeAnyDeployButNotUserAswell", func(t *testing.T) {
-			dstPath, err := os.MkdirTemp("", ctx.Reponame)
-			assert.NoError(t, err)
-			defer util.RemoveAll(dstPath)
+			dstPath := t.TempDir()
 
 			sshURL := createSSHUrl(ctx.GitPath(), u)
 
@@ -151,9 +144,7 @@ func testKeyOnlyOneType(t *testing.T, u *url.URL) {
 			t.Run("FailToPush", doGitPushTestRepositoryFail(dstPath, "origin", "master"))
 
 			otherSSHURL := createSSHUrl(otherCtx.GitPath(), u)
-			dstOtherPath, err := os.MkdirTemp("", otherCtx.Reponame)
-			assert.NoError(t, err)
-			defer util.RemoveAll(dstOtherPath)
+			dstOtherPath := t.TempDir()
 
 			t.Run("AddWriterDeployKeyToOther", doAPICreateDeployKey(otherCtx, keyname, keyFile, false))
 
@@ -168,9 +159,7 @@ func testKeyOnlyOneType(t *testing.T, u *url.URL) {
 
 		t.Run("DeleteRepositoryShouldReleaseKey", func(t *testing.T) {
 			otherSSHURL := createSSHUrl(otherCtx.GitPath(), u)
-			dstOtherPath, err := os.MkdirTemp("", otherCtx.Reponame)
-			assert.NoError(t, err)
-			defer util.RemoveAll(dstOtherPath)
+			dstOtherPath := t.TempDir()
 
 			t.Run("DeleteRepository", doAPIDeleteRepository(ctx))
 
@@ -190,9 +179,7 @@ func testKeyOnlyOneType(t *testing.T, u *url.URL) {
 				userKeyPublicKeyID = publicKey.ID
 			}))
 
-			dstPath, err := os.MkdirTemp("", ctx.Reponame)
-			assert.NoError(t, err)
-			defer util.RemoveAll(dstPath)
+			dstPath := t.TempDir()
 
 			sshURL := createSSHUrl(ctx.GitPath(), u)