fix TestGetCoreClient windows unit test

pkg/minikube/service/service_test.go

@@ -21,6 +21,7 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"path/filepath"
 	"reflect"
 	"strings"
 	"testing"
@@ -712,27 +713,23 @@ preferences: {}
 users:
 - name: minikube
 `
-	var tests = []struct {
+	tests := []struct {
 		description string
-		kubeconfigPath string
 		config      string
 		err         bool
 	}{
 		{
 			description: "ok",
-			kubeconfigPath: "/tmp/kube_config",
 			config:      mockK8sConfig,
 			err:         false,
 		},
 		{
 			description: "empty config",
-			kubeconfigPath: "/tmp/kube_config",
 			config:      "",
 			err:         true,
 		},
 		{
 			description: "broken config",
-			kubeconfigPath: "/tmp/kube_config",
 			config:      "this**is&&not: yaml::valid: file",
 			err:         true,
 		},
@@ -740,17 +737,17 @@ users:
 
 	for _, test := range tests {
 		t.Run(test.description, func(t *testing.T) {
-			mockK8sConfigByte := []byte(test.config)
-			mockK8sConfigPath := test.kubeconfigPath
-			err := os.WriteFile(mockK8sConfigPath, mockK8sConfigByte, 0644)
-			defer os.Remove(mockK8sConfigPath)
-			if err != nil {
-				t.Fatalf("Unexpected error when writing to file %v. Error: %v", test.kubeconfigPath, err)
+			tmpDir := t.TempDir()
+			mockK8sConfigPath := filepath.Join(tmpDir, "kube_config")
+
+			if err := os.WriteFile(mockK8sConfigPath, []byte(test.config), 0600); err != nil {
+				t.Fatalf("failed to write kubeconfig: %v", err)
 			}
 			t.Setenv("KUBECONFIG", mockK8sConfigPath)
 
 			k8s := K8sClientGetter{}
-			_, err = k8s.GetCoreClient("minikube")
+			_, err := k8s.GetCoreClient("minikube")
+
 			if err != nil && !test.err {
 				t.Fatalf("GetCoreClient returned unexpected error: %v", err)
 			}