feat: add_testing (#45)

## Description

<!-- **Please link some issue here describing what you are trying to achieve.**

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At least please give us some description what you are trying to achieve and why your change is needed. -->

relates to #1234

## Checklist

- [ ] Issue was linked above
- [ ] Code format was applied: `make fmt`
- [ ] Examples were added / adjusted (see `examples/` directory)
- [x] Docs are up-to-date: `make generate-docs` (will be checked by CI)
- [ ] Unit tests got implemented or updated
- [ ] Acceptance tests got implemented or updated (see e.g. [here](f5f99d1709/stackit/internal/services/dns/dns_acc_test.go))
- [x] Unit tests are passing: `make test` (will be checked by CI)
- [x] No linter issues: `make lint` (will be checked by CI)

Reviewed-on: #45
Reviewed-by: Andre_Harms <andre.harms@stackit.cloud>
Co-authored-by: Marcel S. Henselin <marcel.henselin@stackit.cloud>
Co-committed-by: Marcel S. Henselin <marcel.henselin@stackit.cloud>

internal/testutils/functions.go

@@ -0,0 +1,125 @@
+package testutils
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+	"os"
+	"path"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+	"text/template"
+)
+
+// GetHomeEnvVariableName Helper function to obtain the home directory on different systems.
+// Based on os.UserHomeDir().
+func GetHomeEnvVariableName() string {
+	env := "HOME"
+	switch runtime.GOOS {
+	case "windows":
+		env = "USERPROFILE"
+	case "plan9":
+		env = "home"
+	}
+	return env
+}
+
+// CreateTemporaryHome create temporary home and initialize the credentials file as well
+func CreateTemporaryHome(createValidCredentialsFile bool, t *testing.T) string {
+	// create a temporary file
+	tempHome, err := os.MkdirTemp("", "tempHome")
+	if err != nil {
+		t.Fatalf("Failed to create temporary home directory: %v", err)
+	}
+
+	// create credentials file in temp directory
+	stackitFolder := path.Join(tempHome, ".stackit")
+	if err := os.Mkdir(stackitFolder, 0o750); err != nil {
+		t.Fatalf("Failed to create stackit folder: %v", err)
+	}
+
+	filePath := path.Join(stackitFolder, "credentials.json")
+	file, err := os.Create(filePath)
+	if err != nil {
+		t.Fatalf("Failed to create credentials file: %v", err)
+	}
+	defer func() {
+		if err := file.Close(); err != nil {
+			t.Fatalf("Error while closing the file: %v", err)
+		}
+	}()
+
+	// Define content, default = invalid token
+	token := "foo_token"
+	if createValidCredentialsFile {
+		token = GetTestProjectServiceAccountJson("")
+	}
+	if _, err = file.WriteString(token); err != nil {
+		t.Fatalf("Error writing to file: %v", err)
+	}
+
+	return tempHome
+}
+
+// SetTemporaryHome Function to overwrite the home folder
+func SetTemporaryHome(tempHomePath string) {
+	env := GetHomeEnvVariableName()
+	if err := os.Setenv(env, tempHomePath); err != nil {
+		fmt.Printf("Error setting temporary home directory %v", err)
+	}
+}
+
+// CleanupTemporaryHome cleanup the temporary home and reset the environment variable
+func CleanupTemporaryHome(tempHomePath string, t *testing.T) {
+	if err := os.RemoveAll(tempHomePath); err != nil {
+		t.Fatalf("Error cleaning up temporary folder: %v", err)
+	}
+	originalHomeDir, err := os.UserHomeDir()
+	if err != nil {
+		t.Fatalf("Failed to restore home directory back to normal: %v", err)
+	}
+	// revert back to original home folder
+	env := GetHomeEnvVariableName()
+	if err := os.Setenv(env, originalHomeDir); err != nil {
+		fmt.Printf("Error resetting temporary home directory %v", err)
+	}
+}
+
+func ucFirst(s string) string {
+	if len(s) == 0 {
+		return ""
+	}
+	return strings.ToUpper(s[:1]) + s[1:]
+}
+
+func StringFromTemplateMust(tplFile string, data any) string {
+	res, err := StringFromTemplate(tplFile, data)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	return res
+}
+
+func StringFromTemplate(tplFile string, data any) (string, error) {
+	fn := template.FuncMap{
+		"ucfirst": ucFirst,
+	}
+
+	file := filepath.Base(tplFile)
+
+	tmpl, err := template.New(file).Funcs(fn).ParseFiles(tplFile)
+	if err != nil {
+		return "", err
+	}
+
+	tplBuf := &bytes.Buffer{}
+
+	err = tmpl.Execute(tplBuf, data)
+	if err != nil {
+		return "", err
+	}
+
+	return tplBuf.String(), nil
+}

internal/testutils/helpers.go

@@ -0,0 +1,465 @@
+package testutils
+
+import (
+	"fmt"
+	"os"
+)
+
+var (
+	CdnCustomEndpoint             = os.Getenv("TF_ACC_CDN_CUSTOM_ENDPOINT")
+	DnsCustomEndpoint             = os.Getenv("TF_ACC_DNS_CUSTOM_ENDPOINT")
+	GitCustomEndpoint             = os.Getenv("TF_ACC_GIT_CUSTOM_ENDPOINT")
+	IaaSCustomEndpoint            = os.Getenv("TF_ACC_IAAS_CUSTOM_ENDPOINT")
+	KMSCustomEndpoint             = os.Getenv("TF_ACC_KMS_CUSTOM_ENDPOINT")
+	LoadBalancerCustomEndpoint    = os.Getenv("TF_ACC_LOADBALANCER_CUSTOM_ENDPOINT")
+	LogMeCustomEndpoint           = os.Getenv("TF_ACC_LOGME_CUSTOM_ENDPOINT")
+	MariaDBCustomEndpoint         = os.Getenv("TF_ACC_MARIADB_CUSTOM_ENDPOINT")
+	ModelServingCustomEndpoint    = os.Getenv("TF_ACC_MODELSERVING_CUSTOM_ENDPOINT")
+	AuthorizationCustomEndpoint   = os.Getenv("TF_ACC_authorization_custom_endpoint")
+	MongoDBFlexCustomEndpoint     = os.Getenv("TF_ACC_MONGODBFLEX_CUSTOM_ENDPOINT")
+	OpenSearchCustomEndpoint      = os.Getenv("TF_ACC_OPENSEARCH_CUSTOM_ENDPOINT")
+	ObservabilityCustomEndpoint   = os.Getenv("TF_ACC_OBSERVABILITY_CUSTOM_ENDPOINT")
+	ObjectStorageCustomEndpoint   = os.Getenv("TF_ACC_OBJECTSTORAGE_CUSTOM_ENDPOINT")
+	PostgresFlexCustomEndpoint    = os.Getenv("TF_ACC_POSTGRESFLEX_CUSTOM_ENDPOINT")
+	RabbitMQCustomEndpoint        = os.Getenv("TF_ACC_RABBITMQ_CUSTOM_ENDPOINT")
+	RedisCustomEndpoint           = os.Getenv("TF_ACC_REDIS_CUSTOM_ENDPOINT")
+	ResourceManagerCustomEndpoint = os.Getenv("TF_ACC_RESOURCEMANAGER_CUSTOM_ENDPOINT")
+	ScfCustomEndpoint             = os.Getenv("TF_ACC_SCF_CUSTOM_ENDPOINT")
+	SecretsManagerCustomEndpoint  = os.Getenv("TF_ACC_SECRETSMANAGER_CUSTOM_ENDPOINT")
+	SQLServerFlexCustomEndpoint   = os.Getenv("TF_ACC_SQLSERVERFLEX_CUSTOM_ENDPOINT")
+	ServerBackupCustomEndpoint    = os.Getenv("TF_ACC_SERVER_BACKUP_CUSTOM_ENDPOINT")
+	ServerUpdateCustomEndpoint    = os.Getenv("TF_ACC_SERVER_UPDATE_CUSTOM_ENDPOINT")
+	ServiceAccountCustomEndpoint  = os.Getenv("TF_ACC_SERVICE_ACCOUNT_CUSTOM_ENDPOINT")
+	SKECustomEndpoint             = os.Getenv("TF_ACC_SKE_CUSTOM_ENDPOINT")
+)
+
+func ObservabilityProviderConfig() string {
+	if ObservabilityCustomEndpoint == "" {
+		return `provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			observability_custom_endpoint = "%s"
+		}`,
+		ObservabilityCustomEndpoint,
+	)
+}
+
+func CdnProviderConfig() string {
+	if CdnCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			enable_beta_resources = true
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			cdn_custom_endpoint = "%s"
+			enable_beta_resources = true
+		}`,
+		CdnCustomEndpoint,
+	)
+}
+
+func DnsProviderConfig() string {
+	if DnsCustomEndpoint == "" {
+		return `provider "stackitprivatepreview" {}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			dns_custom_endpoint = "%s"
+		}`,
+		DnsCustomEndpoint,
+	)
+}
+
+func IaaSProviderConfig() string {
+	if IaaSCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			iaas_custom_endpoint = "%s"
+		}`,
+		IaaSCustomEndpoint,
+	)
+}
+
+func IaaSProviderConfigWithBetaResourcesEnabled() string {
+	if IaaSCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			enable_beta_resources = true
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			enable_beta_resources = true
+			iaas_custom_endpoint = "%s"
+		}`,
+		IaaSCustomEndpoint,
+	)
+}
+
+func IaaSProviderConfigWithExperiments() string {
+	if IaaSCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+  			experiments = [ "routing-tables", "network" ]
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			iaas_custom_endpoint = "%s"
+			experiments = [ "routing-tables", "network" ]
+		}`,
+		IaaSCustomEndpoint,
+	)
+}
+
+func KMSProviderConfig() string {
+	if KMSCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			kms_custom_endpoint = "%s"
+		}`,
+		KMSCustomEndpoint,
+	)
+}
+
+func LoadBalancerProviderConfig() string {
+	if LoadBalancerCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			loadbalancer_custom_endpoint = "%s"
+		}`,
+		LoadBalancerCustomEndpoint,
+	)
+}
+
+func LogMeProviderConfig() string {
+	if LogMeCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			logme_custom_endpoint = "%s"
+		}`,
+		LogMeCustomEndpoint,
+	)
+}
+
+func MariaDBProviderConfig() string {
+	if MariaDBCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			mariadb_custom_endpoint = "%s"
+		}`,
+		MariaDBCustomEndpoint,
+	)
+}
+
+func ModelServingProviderConfig() string {
+	if ModelServingCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}
+		`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			modelserving_custom_endpoint = "%s"
+		}`,
+		ModelServingCustomEndpoint,
+	)
+}
+
+func MongoDBFlexProviderConfig() string {
+	if MongoDBFlexCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			mongodbflex_custom_endpoint = "%s"
+		}`,
+		MongoDBFlexCustomEndpoint,
+	)
+}
+
+func ObjectStorageProviderConfig() string {
+	if ObjectStorageCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			objectstorage_custom_endpoint = "%s"
+		}`,
+		ObjectStorageCustomEndpoint,
+	)
+}
+
+func OpenSearchProviderConfig() string {
+	if OpenSearchCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			opensearch_custom_endpoint = "%s"
+		}`,
+		OpenSearchCustomEndpoint,
+	)
+}
+
+func PostgresFlexProviderConfig(saFile string) string {
+	if PostgresFlexCustomEndpoint == "" {
+		return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+            service_account_key_path = "%s"
+		}`, saFile)
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+            service_account_key_path = "%s"
+			postgresflex_custom_endpoint = "%s"
+		}`,
+		saFile,
+		PostgresFlexCustomEndpoint,
+	)
+}
+
+func RabbitMQProviderConfig() string {
+	if RabbitMQCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			rabbitmq_custom_endpoint = "%s"
+		}`,
+		RabbitMQCustomEndpoint,
+	)
+}
+
+func RedisProviderConfig() string {
+	if RedisCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			redis_custom_endpoint = "%s"
+		}`,
+		RedisCustomEndpoint,
+	)
+}
+
+func ResourceManagerProviderConfig() string {
+	key := GetTestProjectServiceAccountJson("")
+	if ResourceManagerCustomEndpoint == "" || AuthorizationCustomEndpoint == "" {
+		return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			service_account_key = "%s"
+		}`,
+			key,
+		)
+	}
+	return fmt.Sprintf(`
+	provider "stackitprivatepreview" {
+		resourcemanager_custom_endpoint = "%s"
+		authorization_custom_endpoint = "%s"
+		service_account_token = "%s"
+	}`,
+		ResourceManagerCustomEndpoint,
+		AuthorizationCustomEndpoint,
+		key,
+	)
+}
+
+func SecretsManagerProviderConfig() string {
+	if SecretsManagerCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			secretsmanager_custom_endpoint = "%s"
+		}`,
+		SecretsManagerCustomEndpoint,
+	)
+}
+
+func SQLServerFlexProviderConfig(saFile string) string {
+	if SQLServerFlexCustomEndpoint == "" {
+		return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+            service_account_key_path = "%s"
+		}`, saFile)
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+            service_account_key_path = "%s"
+			sqlserverflex_custom_endpoint = "%s"
+		}`,
+		saFile,
+		SQLServerFlexCustomEndpoint,
+	)
+}
+
+func ServerBackupProviderConfig() string {
+	if ServerBackupCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+			enable_beta_resources = true
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			server_backup_custom_endpoint = "%s"
+			enable_beta_resources = true
+		}`,
+		ServerBackupCustomEndpoint,
+	)
+}
+
+func ServerUpdateProviderConfig() string {
+	if ServerUpdateCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+			enable_beta_resources = true
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			server_update_custom_endpoint = "%s"
+			enable_beta_resources = true
+		}`,
+		ServerUpdateCustomEndpoint,
+	)
+}
+
+func SKEProviderConfig() string {
+	if SKECustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			ske_custom_endpoint = "%s"
+		}`,
+		SKECustomEndpoint,
+	)
+}
+
+func AuthorizationProviderConfig() string {
+	if AuthorizationCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+			experiments = ["iam"]
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			authorization_custom_endpoint = "%s"
+			experiments = ["iam"]
+		}`,
+		AuthorizationCustomEndpoint,
+	)
+}
+
+func ServiceAccountProviderConfig() string {
+	if ServiceAccountCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+			enable_beta_resources = true
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			service_account_custom_endpoint = "%s"
+			enable_beta_resources = true
+		}`,
+		ServiceAccountCustomEndpoint,
+	)
+}
+
+func GitProviderConfig() string {
+	if GitCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+			enable_beta_resources = true
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			git_custom_endpoint = "%s"
+			enable_beta_resources = true
+		}`,
+		GitCustomEndpoint,
+	)
+}
+
+func ScfProviderConfig() string {
+	if ScfCustomEndpoint == "" {
+		return `
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+		}`
+	}
+	return fmt.Sprintf(`
+		provider "stackitprivatepreview" {
+			default_region = "eu01"
+			scf_custom_endpoint = "%s"
+		}`,
+		ScfCustomEndpoint,
+	)
+}

internal/testutils/testutils.go

@@ -0,0 +1,219 @@
+package testutils
+
+import (
+	"fmt"
+	"log"
+	"log/slog"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/hashicorp/terraform-plugin-framework/providerserver"
+	"github.com/hashicorp/terraform-plugin-go/tfprotov6"
+	"github.com/hashicorp/terraform-plugin-testing/config"
+	"github.com/hashicorp/terraform-plugin-testing/echoprovider"
+	"github.com/joho/godotenv"
+
+	"tf-provider.git.onstackit.cloud/stackit-dev-tools/terraform-provider-stackitprivatepreview/stackit"
+)
+
+const (
+	// Default location of credentials JSON
+	// credentialsFilePath = ".stackit/credentials.json" //nolint:gosec // linter false positive
+	serviceAccountFilePath = ".stackit/service_account.json"
+)
+
+var (
+	// TestAccProtoV6ProviderFactories is used to instantiate a provider during
+	// acceptance testing. The factory function will be invoked for every Terraform
+	// CLI command executed to create a provider server to which the CLI can
+	// reattach.
+	TestAccProtoV6ProviderFactories = map[string]func() (tfprotov6.ProviderServer, error){
+		"stackitprivatepreview": providerserver.NewProtocol6WithError(stackit.New("test-version")()),
+	}
+
+	// TestEphemeralAccProtoV6ProviderFactories is used to instantiate a provider during
+	// acceptance testing. The factory function will be invoked for every Terraform
+	// CLI command executed to create a provider server to which the CLI can
+	// reattach.
+	//
+	// See the Terraform acceptance test documentation on ephemeral resources for more information:
+	// https://developer.hashicorp.com/terraform/plugin/testing/acceptance-tests/ephemeral-resources
+	TestEphemeralAccProtoV6ProviderFactories = map[string]func() (tfprotov6.ProviderServer, error){
+		"stackitprivatepreview": providerserver.NewProtocol6WithError(stackit.New("test-version")()),
+		"echo":                  echoprovider.NewProviderServer(),
+	}
+
+	// E2ETestsEnabled checks if end-to-end tests should be run.
+	// It is enabled when the TF_ACC environment variable is set to "1".
+	E2ETestsEnabled = os.Getenv("TF_ACC") == "1"
+	// OrganizationId is the id of organization used for tests
+	OrganizationId = os.Getenv("TF_ACC_ORGANIZATION_ID")
+	// ProjectId is the id of project used for tests
+	ProjectId = os.Getenv("TF_ACC_PROJECT_ID")
+	Region    = os.Getenv("TF_ACC_REGION")
+	// ServiceAccountFile is the json file of the service account
+	ServiceAccountFile = os.Getenv("TF_ACC_SERVICE_ACCOUNT_FILE")
+	// ServerId is the id of a server used for some tests
+	ServerId = getenv("TF_ACC_SERVER_ID", "")
+	// TestProjectParentContainerID is the container id of the parent resource under which projects are created as part of the resource-manager acceptance tests
+	TestProjectParentContainerID = os.Getenv("TF_ACC_TEST_PROJECT_PARENT_CONTAINER_ID")
+	// TestProjectParentUUID is the uuid of the parent resource under which projects are created as part of the resource-manager acceptance tests
+	TestProjectParentUUID = os.Getenv("TF_ACC_TEST_PROJECT_PARENT_UUID")
+	// TestProjectServiceAccountEmail is the e-mail of a service account with admin permissions on the organization under which projects are created as part of the resource-manager acceptance tests
+	TestProjectServiceAccountEmail = os.Getenv("TF_ACC_TEST_PROJECT_SERVICE_ACCOUNT_EMAIL")
+	// TestProjectUserEmail is the e-mail of a user for the project created as part of the resource-manager acceptance tests
+	// Default email: acc-test@sa.stackit.cloud
+	TestProjectUserEmail = getenv("TF_ACC_TEST_PROJECT_USER_EMAIL", "acc-test@sa.stackit.cloud")
+	// TestImageLocalFilePath is the local path to an image file used for image acceptance tests
+	TestImageLocalFilePath = getenv("TF_ACC_TEST_IMAGE_LOCAL_FILE_PATH", "default")
+)
+
+func Setup() {
+	root, err := getRoot()
+	if err != nil {
+		log.Fatalln(err)
+	}
+	err = godotenv.Load(fmt.Sprintf("%s/.env", *root))
+	if err != nil {
+		slog.Info("could not find .env file - not loading .env")
+		return
+	}
+	slog.Info("loaded .env file", "path", *root)
+}
+
+func getRoot() (*string, error) {
+	cmd := exec.Command("git", "rev-parse", "--show-toplevel")
+	out, err := cmd.Output()
+	if err != nil {
+		return nil, err
+	}
+	lines := strings.Split(string(out), "\n")
+	return &lines[0], nil
+}
+
+func ResourceNameWithDateTime(name string) string {
+	dateTime := time.Now().Format(time.RFC3339)
+	// Remove timezone to have a smaller datetime
+	dateTimeTrimmed, _, _ := strings.Cut(dateTime, "+")
+	return fmt.Sprintf("tf-acc-%s-%s", name, dateTimeTrimmed)
+}
+
+func GetTestProjectServiceAccountJson(path string) string {
+	var err error
+	token, tokenSet := os.LookupEnv("TF_ACC_TEST_PROJECT_SERVICE_ACCOUNT_JSON")
+	if !tokenSet || token == "" {
+		token, err = readTestServiceAccountJsonFromFile(path)
+		if err != nil {
+			return ""
+		}
+	}
+	return token
+}
+
+//func GetTestProjectServiceAccountToken(path string) string {
+//	var err error
+//	token, tokenSet := os.LookupEnv("TF_ACC_TEST_PROJECT_SERVICE_ACCOUNT_TOKEN")
+//	if !tokenSet || token == "" {
+//		token, err = readTestTokenFromCredentialsFile(path)
+//		if err != nil {
+//			return ""
+//		}
+//	}
+//	return token
+//}
+//
+//func readTestTokenFromCredentialsFile(path string) (string, error) {
+//	if path == "" {
+//		customPath, customPathSet := os.LookupEnv("STACKIT_CREDENTIALS_PATH")
+//		if !customPathSet || customPath == "" {
+//			path = credentialsFilePath
+//			home, err := os.UserHomeDir()
+//			if err != nil {
+//				return "", fmt.Errorf("getting home directory: %w", err)
+//			}
+//			path = filepath.Join(home, path)
+//		} else {
+//			path = customPath
+//		}
+//	}
+//
+//	credentialsRaw, err := os.ReadFile(path)
+//	if err != nil {
+//		return "", fmt.Errorf("opening file: %w", err)
+//	}
+//
+//	var credentials struct {
+//		TF_ACC_TEST_PROJECT_SERVICE_ACCOUNT_TOKEN string `json:"TF_ACC_TEST_PROJECT_SERVICE_ACCOUNT_TOKEN"`
+//	}
+//	err = json.Unmarshal(credentialsRaw, &credentials)
+//	if err != nil {
+//		return "", fmt.Errorf("unmarshalling credentials: %w", err)
+//	}
+//	return credentials.TF_ACC_TEST_PROJECT_SERVICE_ACCOUNT_TOKEN, nil
+//}
+
+func readTestServiceAccountJsonFromFile(path string) (string, error) {
+	if path == "" {
+		customPath, customPathSet := os.LookupEnv("STACKIT_SERVICE_ACCOUNT_PATH")
+		if !customPathSet || customPath == "" {
+			path = serviceAccountFilePath
+			home, err := os.UserHomeDir()
+			if err != nil {
+				return "", fmt.Errorf("getting home directory: %w", err)
+			}
+			path = filepath.Join(home, path)
+		} else {
+			path = customPath
+		}
+	}
+
+	credentialsRaw, err := os.ReadFile(path)
+	if err != nil {
+		return "", fmt.Errorf("opening file: %w", err)
+	}
+	return string(credentialsRaw), nil
+}
+
+func getenv(key, defaultValue string) string {
+	val := os.Getenv(key)
+	if val == "" {
+		return defaultValue
+	}
+	return val
+}
+
+// CreateDefaultLocalFile is a helper for local_file_path. No real data is created
+func CreateDefaultLocalFile() os.File {
+	// Define the file name and size
+	fileName := "test-512k.img"
+	size := 512 * 1024 // 512 KB
+
+	// Create the file
+	file, err := os.Create(fileName)
+	if err != nil {
+		panic(err)
+	}
+
+	// Seek to the desired position (512 KB)
+	_, err = file.Seek(int64(size), 0)
+	if err != nil {
+		panic(err)
+	}
+
+	return *file
+}
+
+func ConvertConfigVariable(variable config.Variable) string {
+	tmpByteArray, _ := variable.MarshalJSON()
+	// In case the variable is a string, the quotes should be removed
+	if tmpByteArray[0] == '"' && tmpByteArray[len(tmpByteArray)-1] == '"' {
+		result := string(tmpByteArray[1 : len(tmpByteArray)-1])
+		// Replace escaped quotes which where added MarshalJSON
+		rawString := strings.ReplaceAll(result, `\"`, `"`)
+		return rawString
+	}
+	return string(tmpByteArray)
+}

internal/testutils/testutils_test.go

@@ -0,0 +1,48 @@
+package testutils
+
+import (
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-testing/config"
+)
+
+func TestConvertConfigVariable(t *testing.T) {
+	tests := []struct {
+		name     string
+		variable config.Variable
+		want     string
+	}{
+		{
+			name:     "string",
+			variable: config.StringVariable("test"),
+			want:     "test",
+		},
+		{
+			name:     "bool: true",
+			variable: config.BoolVariable(true),
+			want:     "true",
+		},
+		{
+			name:     "bool: false",
+			variable: config.BoolVariable(false),
+			want:     "false",
+		},
+		{
+			name:     "integer",
+			variable: config.IntegerVariable(10),
+			want:     "10",
+		},
+		{
+			name:     "quoted string",
+			variable: config.StringVariable(`instance =~ ".*"`),
+			want:     `instance =~ ".*"`,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := ConvertConfigVariable(tt.variable); got != tt.want {
+				t.Errorf("ConvertConfigVariable() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}