test: use T.TempDir to create temporary test directory

This commit replaces `ioutil.TempDir` with `t.TempDir` in tests. The
directory created by `t.TempDir` is automatically removed when the test
and all its subtests complete.

Prior to this commit, temporary directory created using `ioutil.TempDir`
needs to be removed manually by calling `os.RemoveAll`, which is omitted
in some tests. The error handling boilerplate e.g.
	defer func() {
		if err := os.RemoveAll(dir); err != nil {
			t.Fatal(err)
		}
	}
is also tedious, but `t.TempDir` handles this for us nicely.

Reference: https://pkg.go.dev/testing#T.TempDir
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

pkg/kn/commands/completion_helper_test.go

@@ -16,7 +16,6 @@ package commands
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path"
 	"testing"
@@ -703,8 +702,6 @@ func TestResourceNameCompletionFuncRevision(t *testing.T) {
 
 func TestResourceNameCompletionFuncGitOps(t *testing.T) {
 	tempDir := setupTempDir(t)
-	assert.Assert(t, tempDir != "")
-	defer os.RemoveAll(tempDir)
 
 	completionFunc := ResourceNameCompletionFunc(knParams)
 
@@ -1594,11 +1591,10 @@ func getResourceCommandWithTestSubcommand(resource string, addNamespace, addSubc
 }
 
 func setupTempDir(t *testing.T) string {
-	tempDir, err := ioutil.TempDir("", "test-dir")
-	assert.NilError(t, err)
+	tempDir := t.TempDir()
 
 	svcPath := path.Join(tempDir, "test-ns", "ksvc")
-	err = os.MkdirAll(svcPath, 0700)
+	err := os.MkdirAll(svcPath, 0700)
 	assert.NilError(t, err)
 
 	for i, testSvc := range []servingv1.Service{testSvc1, testSvc2, testSvc3} {

pkg/kn/commands/namespaced_test.go

@@ -139,13 +139,11 @@ func TestGetNamespaceAllNamespacesNotDefined(t *testing.T) {
 }
 
 func TestGetNamespaceFallback(t *testing.T) {
-	tempDir, err := ioutil.TempDir("", "kn-unit-tests")
-	defer os.RemoveAll(tempDir)
-	assert.NilError(t, err)
+	tempDir := t.TempDir()
 
 	t.Run("MockConfig", func(t *testing.T) {
 		tempFile := filepath.Join(tempDir, "mock")
-		err = ioutil.WriteFile(tempFile, []byte(BASIC_KUBECONFIG), test.FileModeReadWrite)
+		err := ioutil.WriteFile(tempFile, []byte(BASIC_KUBECONFIG), test.FileModeReadWrite)
 		assert.NilError(t, err)
 
 		kp := &KnParams{KubeCfgPath: tempFile}
@@ -163,7 +161,7 @@ func TestGetNamespaceFallback(t *testing.T) {
 
 	t.Run("EmptyConfig", func(t *testing.T) {
 		tempFile := filepath.Join(tempDir, "empty")
-		err = ioutil.WriteFile(tempFile, []byte(""), test.FileModeReadWrite)
+		err := ioutil.WriteFile(tempFile, []byte(""), test.FileModeReadWrite)
 		assert.NilError(t, err)
 
 		kp := &KnParams{KubeCfgPath: tempFile}
@@ -190,14 +188,12 @@ func TestGetNamespaceFallback(t *testing.T) {
 }
 
 func TestCurrentNamespace(t *testing.T) {
-	tempDir, err := ioutil.TempDir("", "kn-unit-tests")
-	defer os.RemoveAll(tempDir)
-	assert.NilError(t, err)
+	tempDir := t.TempDir()
 
 	t.Run("EmptyConfig", func(t *testing.T) {
 		// Invalid kubeconfig
 		tempFile := filepath.Join(tempDir, "empty")
-		err = ioutil.WriteFile(tempFile, []byte(""), test.FileModeReadWrite)
+		err := ioutil.WriteFile(tempFile, []byte(""), test.FileModeReadWrite)
 		assert.NilError(t, err)
 
 		kp := &KnParams{KubeCfgPath: tempFile}
@@ -234,7 +230,7 @@ func TestCurrentNamespace(t *testing.T) {
 	t.Run("MockConfig", func(t *testing.T) {
 		// Fallback to "default" namespace from mock kubeconfig
 		tempFile := filepath.Join(tempDir, "mock")
-		err = ioutil.WriteFile(tempFile, []byte(BASIC_KUBECONFIG), test.FileModeReadWrite)
+		err := ioutil.WriteFile(tempFile, []byte(BASIC_KUBECONFIG), test.FileModeReadWrite)
 		assert.NilError(t, err)
 		kp := &KnParams{KubeCfgPath: tempFile}
 		actual, err := kp.CurrentNamespace()

pkg/kn/commands/plugin/list_test.go

@@ -133,8 +133,7 @@ func TestPluginListExtendingBuiltinCommandGroup(t *testing.T) {
 // Private
 
 func prepareTestSetup(t *testing.T, args ...interface{}) (string, func()) {
-	tmpPathDir, err := ioutil.TempDir("", "plugin_list")
-	assert.NilError(t, err)
+	tmpPathDir := t.TempDir()
 
 	// Prepare configuration to for our test
 	oldConfig := config.GlobalConfig
@@ -151,7 +150,6 @@ func prepareTestSetup(t *testing.T, args ...interface{}) (string, func()) {
 
 	return tmpPathDir, func() {
 		config.GlobalConfig = oldConfig
-		os.RemoveAll(tmpPathDir)
 	}
 }
 

pkg/kn/commands/service/create_test.go

@@ -894,9 +894,7 @@ func TestServiceCreateFromFile(t *testing.T) {
 }
 
 func testWithServiceFiles(t *testing.T, testFunction func(t *testing.T, file string)) {
-	tempDir, err := ioutil.TempDir("", "kn-file")
-	defer os.RemoveAll(tempDir)
-	assert.NilError(t, err)
+	tempDir := t.TempDir()
 
 	for _, d := range []struct {
 		filename string
@@ -910,7 +908,7 @@ func testWithServiceFiles(t *testing.T, testFunction func(t *testing.T, file str
 		},
 	} {
 		tempFile := filepath.Join(tempDir, d.filename)
-		err = ioutil.WriteFile(tempFile, []byte(d.content), os.FileMode(0666))
+		err := ioutil.WriteFile(tempFile, []byte(d.content), os.FileMode(0666))
 		assert.NilError(t, err)
 		testFunction(t, tempFile)
 	}
@@ -941,14 +939,12 @@ func TestServiceCreateFileError(t *testing.T) {
 }
 
 func TestServiceCreateInvalidDataJSON(t *testing.T) {
-	tempDir, err := ioutil.TempDir("", "kn-file")
-	defer os.RemoveAll(tempDir)
-	assert.NilError(t, err)
+	tempDir := t.TempDir()
 	tempFile := filepath.Join(tempDir, "invalid.json")
 
 	// Double curly bracket at the beginning of file
 	invalidData := strings.Replace(serviceJSON, "{\n", "{{\n", 1)
-	err = ioutil.WriteFile(tempFile, []byte(invalidData), os.FileMode(0666))
+	err := ioutil.WriteFile(tempFile, []byte(invalidData), os.FileMode(0666))
 	assert.NilError(t, err)
 	_, _, _, err = fakeServiceCreate([]string{"service", "create", "foo", "--filename", tempFile}, false)
 	assert.Assert(t, util.ContainsAll(err.Error(), "invalid", "character", "'{'", "beginning"))
@@ -969,14 +965,12 @@ func TestServiceCreateInvalidDataJSON(t *testing.T) {
 }
 
 func TestServiceCreateInvalidDataYAML(t *testing.T) {
-	tempDir, err := ioutil.TempDir("", "kn-file")
-	defer os.RemoveAll(tempDir)
-	assert.NilError(t, err)
+	tempDir := t.TempDir()
 	tempFile := filepath.Join(tempDir, "invalid.yaml")
 
 	// Remove dash
 	invalidData := strings.Replace(serviceYAML, "- image", "image", 1)
-	err = ioutil.WriteFile(tempFile, []byte(invalidData), os.FileMode(0666))
+	err := ioutil.WriteFile(tempFile, []byte(invalidData), os.FileMode(0666))
 	assert.NilError(t, err)
 	_, _, _, err = fakeServiceCreate([]string{"service", "create", "foo", "--filename", tempFile}, false)
 	assert.Assert(t, util.ContainsAll(err.Error(), "mapping", "values", "not", "allowed"))
@@ -997,12 +991,10 @@ func TestServiceCreateInvalidDataYAML(t *testing.T) {
 }
 
 func TestServiceCreateFromYAMLWithOverride(t *testing.T) {
-	tempDir, err := ioutil.TempDir("", "kn-file")
-	defer os.RemoveAll(tempDir)
-	assert.NilError(t, err)
+	tempDir := t.TempDir()
 
 	tempFile := filepath.Join(tempDir, "service.yaml")
-	err = ioutil.WriteFile(tempFile, []byte(serviceYAML), os.FileMode(0666))
+	err := ioutil.WriteFile(tempFile, []byte(serviceYAML), os.FileMode(0666))
 	assert.NilError(t, err)
 	// Merge env vars
 	expectedEnvVars := map[string]string{
@@ -1077,12 +1069,10 @@ func TestServiceCreateFromYAMLWithOverride(t *testing.T) {
 }
 
 func TestServiceCreateFromYAMLWithOverrideError(t *testing.T) {
-	tempDir, err := ioutil.TempDir("", "kn-file")
-	defer os.RemoveAll(tempDir)
-	assert.NilError(t, err)
+	tempDir := t.TempDir()
 
 	tempFile := filepath.Join(tempDir, "service.yaml")
-	err = ioutil.WriteFile(tempFile, []byte(serviceYAML), os.FileMode(0666))
+	err := ioutil.WriteFile(tempFile, []byte(serviceYAML), os.FileMode(0666))
 	assert.NilError(t, err)
 
 	_, _, _, err = fakeServiceCreate([]string{

pkg/kn/commands/service/import_test.go

@@ -44,9 +44,8 @@ func TestServiceImportFilenameError(t *testing.T) {
 }
 
 func TestServiceImportExistError(t *testing.T) {
-	file, err := generateFile([]byte(exportYAML))
+	file, err := generateFile(t, []byte(exportYAML))
 	assert.NilError(t, err)
-	defer os.RemoveAll(filepath.Dir(file))
 
 	client := knclient.NewMockKnServiceClient(t)
 	r := client.Recorder()
@@ -60,9 +59,8 @@ func TestServiceImportExistError(t *testing.T) {
 }
 
 func TestServiceImport(t *testing.T) {
-	file, err := generateFile([]byte(exportYAML))
+	file, err := generateFile(t, []byte(exportYAML))
 	assert.NilError(t, err)
-	defer os.RemoveAll(filepath.Dir(file))
 
 	client := knclient.NewMockKnServiceClient(t)
 	r := client.Recorder()
@@ -80,9 +78,8 @@ func TestServiceImport(t *testing.T) {
 }
 
 func TestServiceImportNoWait(t *testing.T) {
-	file, err := generateFile([]byte(exportYAML))
+	file, err := generateFile(t, []byte(exportYAML))
 	assert.NilError(t, err)
-	defer os.RemoveAll(filepath.Dir(file))
 
 	client := knclient.NewMockKnServiceClient(t)
 	r := client.Recorder()
@@ -98,9 +95,8 @@ func TestServiceImportNoWait(t *testing.T) {
 }
 
 func TestServiceImportWitRevisions(t *testing.T) {
-	file, err := generateFile([]byte(exportWithRevisionsYAML))
+	file, err := generateFile(t, []byte(exportWithRevisionsYAML))
 	assert.NilError(t, err)
-	defer os.RemoveAll(filepath.Dir(file))
 
 	client := knclient.NewMockKnServiceClient(t)
 	r := client.Recorder()
@@ -120,14 +116,11 @@ func TestServiceImportWitRevisions(t *testing.T) {
 	r.Validate()
 }
 
-func generateFile(fileContent []byte) (string, error) {
-	tempDir, err := ioutil.TempDir("", "kn-file")
-	if err != nil {
-		return "", err
-	}
+func generateFile(t *testing.T, fileContent []byte) (string, error) {
+	tempDir := t.TempDir()
 
 	tempFile := filepath.Join(tempDir, "import.yaml")
-	if err = ioutil.WriteFile(tempFile, fileContent, os.FileMode(0666)); err != nil {
+	if err := ioutil.WriteFile(tempFile, fileContent, os.FileMode(0666)); err != nil {
 		return "", err
 	}
 	return tempFile, nil

pkg/kn/commands/types_test.go

@@ -121,11 +121,9 @@ type typeTestCase struct {
 func TestGetClientConfig(t *testing.T) {
 	multiConfigs := fmt.Sprintf("%s%s%s", "/testing/assets/kube-config-01.yml", string(os.PathListSeparator), "/testing/assets/kube-config-02.yml")
 
-	tempDir, err := ioutil.TempDir("", "kn-unit-tests")
-	defer os.RemoveAll(tempDir)
-	assert.NilError(t, err)
+	tempDir := t.TempDir()
 	tempFile := filepath.Join(tempDir, "mock")
-	err = ioutil.WriteFile(tempFile, []byte(BASIC_KUBECONFIG), test.FileModeReadWrite)
+	err := ioutil.WriteFile(tempFile, []byte(BASIC_KUBECONFIG), test.FileModeReadWrite)
 	assert.NilError(t, err)
 
 	for _, tc := range []typeTestCase{

pkg/kn/config/config_test.go

@@ -109,8 +109,7 @@ sink:
 }
 
 func setupConfig(t *testing.T, configContent string) (string, func()) {
-	tmpDir, err := ioutil.TempDir("", "configContent")
-	assert.NilError(t, err)
+	tmpDir := t.TempDir()
 
 	// Avoid to be fooled by the things in the the real homedir
 	oldHome := os.Getenv("HOME")
@@ -124,7 +123,7 @@ func setupConfig(t *testing.T, configContent string) (string, func()) {
 	if configContent != "" {
 		cfgFile = filepath.Join(tmpDir, "config.yaml")
 		os.Args = []string{"kn", "--config", cfgFile}
-		err = ioutil.WriteFile(cfgFile, []byte(configContent), 0644)
+		err := ioutil.WriteFile(cfgFile, []byte(configContent), 0644)
 		assert.NilError(t, err)
 	}
 
@@ -138,7 +137,6 @@ func setupConfig(t *testing.T, configContent string) (string, func()) {
 
 	return cfgFile, func() {
 		// Cleanup everything
-		os.RemoveAll(tmpDir)
 		os.Setenv("HOME", oldHome)
 		os.Args = backupArgs
 		bootstrapDefaults = initDefaults()

pkg/kn/flags/podspec_helper_test.go

@@ -879,9 +879,7 @@ containers:
 	assert.NilError(t, err)
 	assert.Equal(t, len(fromFile.Containers), 2)
 
-	tempDir, err := ioutil.TempDir("", "kn-file")
-	defer os.RemoveAll(tempDir)
-	assert.NilError(t, err)
+	tempDir := t.TempDir()
 	fileName := filepath.Join(tempDir, "container.yaml")
 	ioutil.WriteFile(fileName, []byte(rawInput), test.FileModeReadWrite)
 	fromFile, err = decodeContainersFromFile(fileName)

pkg/kn/flags/podspec_test.go

@@ -244,8 +244,7 @@ containers:
 			"Input:file",
 			rawInput,
 			func(data string) string {
-				tempDir, err := ioutil.TempDir("", "kn-file")
-				assert.NilError(t, err)
+				tempDir := t.TempDir()
 				fileName := filepath.Join(tempDir, "container.yaml")
 				ioutil.WriteFile(fileName, []byte(data), test.FileModeReadWrite)
 				return fileName

pkg/kn/plugin/manager_test.go

@@ -357,8 +357,7 @@ func setup(t *testing.T) testContext {
 }
 
 func setupWithPathLookup(t *testing.T, lookupInPath bool) testContext {
-	tmpPathDir, err := ioutil.TempDir("", "plugin_list")
-	assert.NilError(t, err)
+	tmpPathDir := t.TempDir()
 	return testContext{
 		pluginsDir:    tmpPathDir,
 		pluginManager: NewManager(tmpPathDir, lookupInPath),
@@ -388,13 +387,11 @@ func executePlugin(plugin Plugin, args []string) (string, error) {
 
 // Prepare a directory and set the path to this directory
 func preparePathDirectory(t *testing.T) (string, func()) {
-	tmpPathDir, err := ioutil.TempDir("", "plugin_path")
-	assert.NilError(t, err)
+	tmpPathDir := t.TempDir()
 
 	oldPath := os.Getenv("PATH")
 	os.Setenv("PATH", fmt.Sprintf("%s%c%s", tmpPathDir, os.PathListSeparator, "fast-forward-this-year-plz"))
 	return tmpPathDir, func() {
-		os.RemoveAll(tmpPathDir)
 		os.Setenv("PATH", oldPath)
 	}
 }

pkg/serving/v1/gitops_test.go

@@ -16,8 +16,6 @@ package v1
 
 import (
 	"context"
-	"io/ioutil"
-	"os"
 	"path/filepath"
 	"testing"
 	"time"
@@ -35,12 +33,9 @@ import (
 )
 
 func TestGitOpsOperations(t *testing.T) {
-	c1TempDir, err := ioutil.TempDir("", "kn-files-cluster1")
-	assert.NilError(t, err)
-	c2TempDir, err := ioutil.TempDir("", "kn-files-cluster2")
-	assert.NilError(t, err)
-	defer os.RemoveAll(c1TempDir)
-	defer os.RemoveAll(c2TempDir)
+	c1TempDir := t.TempDir()
+	c2TempDir := t.TempDir()
+
 	// create clients
 	fooclient := NewKnServingGitOpsClient("foo-ns", c1TempDir)
 	bazclient := NewKnServingGitOpsClient("baz-ns", c1TempDir)
@@ -141,9 +136,7 @@ func TestGitOpsOperations(t *testing.T) {
 }
 
 func TestGitOpsSingleFile(t *testing.T) {
-	tmpDir, err := ioutil.TempDir("", "singlefile")
-	assert.NilError(t, err)
-	defer os.RemoveAll(tmpDir)
+	tmpDir := t.TempDir()
 	// create clients
 	fooclient := NewKnServingGitOpsClient("", filepath.Join(tmpDir, "test.yaml"))
 	barclient := NewKnServingGitOpsClient("", filepath.Join(tmpDir, "test.yml"))