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>

3 files changed, 8 insertions, 25 deletions

diff --git a/modules/git/commit_info_test.go b/modules/git/commit_info_test.go
index a12452c404..4bc3596896 100644
--- a/modules/git/commit_info_test.go
+++ b/modules/git/commit_info_test.go
@@ -6,13 +6,10 @@ package git
 
 import (
 	"context"
-	"os"
 	"path/filepath"
 	"testing"
 	"time"
 
-	"code.gitea.io/gitea/modules/util"
-
 	"github.com/stretchr/testify/assert"
 )
 
@@ -20,18 +17,14 @@ const (
 	testReposDir = "tests/repos/"
 )
 
-func cloneRepo(url, name string) (string, error) {
-	repoDir, err := os.MkdirTemp("", name)
-	if err != nil {
-		return "", err
-	}
+func cloneRepo(tb testing.TB, url string) (string, error) {
+	repoDir := tb.TempDir()
 	if err := Clone(DefaultContext, url, repoDir, CloneRepoOptions{
 		Mirror:  false,
 		Bare:    false,
 		Quiet:   true,
 		Timeout: 5 * time.Minute,
 	}); err != nil {
-		_ = util.RemoveAll(repoDir)
 		return "", err
 	}
 	return repoDir, nil
@@ -118,11 +111,10 @@ func TestEntries_GetCommitsInfo(t *testing.T) {
 
 	testGetCommitsInfo(t, bareRepo1)
 
-	clonedPath, err := cloneRepo(bareRepo1Path, "repo1_TestEntries_GetCommitsInfo")
+	clonedPath, err := cloneRepo(t, bareRepo1Path)
 	if err != nil {
 		assert.NoError(t, err)
 	}
-	defer util.RemoveAll(clonedPath)
 	clonedRepo1, err := openRepositoryWithDefaultContext(clonedPath)
 	if err != nil {
 		assert.NoError(t, err)
@@ -150,11 +142,10 @@ func BenchmarkEntries_GetCommitsInfo(b *testing.B) {
 		var commit *Commit
 		var entries Entries
 		var repo *Repository
-		repoPath, err := cloneRepo(benchmark.url, benchmark.name)
+		repoPath, err := cloneRepo(b, benchmark.url)
 		if err != nil {
 			b.Fatal(err)
 		}
-		defer util.RemoveAll(repoPath)
 
 		if repo, err = openRepositoryWithDefaultContext(repoPath); err != nil {
 			b.Fatal(err)
diff --git a/modules/git/repo_compare_test.go b/modules/git/repo_compare_test.go
index 245920c2bd..63f7254dea 100644
--- a/modules/git/repo_compare_test.go
+++ b/modules/git/repo_compare_test.go
@@ -10,19 +10,16 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/modules/util"
-
 	"github.com/stretchr/testify/assert"
 )
 
 func TestGetFormatPatch(t *testing.T) {
 	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare")
-	clonedPath, err := cloneRepo(bareRepo1Path, "repo1_TestGetFormatPatch")
+	clonedPath, err := cloneRepo(t, bareRepo1Path)
 	if err != nil {
 		assert.NoError(t, err)
 		return
 	}
-	defer util.RemoveAll(clonedPath)
 
 	repo, err := openRepositoryWithDefaultContext(clonedPath)
 	if err != nil {
@@ -84,12 +81,11 @@ func TestReadWritePullHead(t *testing.T) {
 	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare")
 
 	// As we are writing we should clone the repository first
-	clonedPath, err := cloneRepo(bareRepo1Path, "TestReadWritePullHead")
+	clonedPath, err := cloneRepo(t, bareRepo1Path)
 	if err != nil {
 		assert.NoError(t, err)
 		return
 	}
-	defer util.RemoveAll(clonedPath)
 
 	repo, err := openRepositoryWithDefaultContext(clonedPath)
 	if err != nil {
diff --git a/modules/git/repo_tag_test.go b/modules/git/repo_tag_test.go
index 9d84672862..6a00473bb7 100644
--- a/modules/git/repo_tag_test.go
+++ b/modules/git/repo_tag_test.go
@@ -8,8 +8,6 @@ import (
 	"path/filepath"
 	"testing"
 
-	"code.gitea.io/gitea/modules/util"
-
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -38,12 +36,11 @@ func TestRepository_GetTags(t *testing.T) {
 func TestRepository_GetTag(t *testing.T) {
 	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare")
 
-	clonedPath, err := cloneRepo(bareRepo1Path, "TestRepository_GetTag")
+	clonedPath, err := cloneRepo(t, bareRepo1Path)
 	if err != nil {
 		assert.NoError(t, err)
 		return
 	}
-	defer util.RemoveAll(clonedPath)
 
 	bareRepo1, err := openRepositoryWithDefaultContext(clonedPath)
 	if err != nil {
@@ -143,12 +140,11 @@ func TestRepository_GetTag(t *testing.T) {
 func TestRepository_GetAnnotatedTag(t *testing.T) {
 	bareRepo1Path := filepath.Join(testReposDir, "repo1_bare")
 
-	clonedPath, err := cloneRepo(bareRepo1Path, "TestRepository_GetAnnotatedTag")
+	clonedPath, err := cloneRepo(t, bareRepo1Path)
 	if err != nil {
 		assert.NoError(t, err)
 		return
 	}
-	defer util.RemoveAll(clonedPath)
 
 	bareRepo1, err := openRepositoryWithDefaultContext(clonedPath)
 	if err != nil {