remove individual config dirs

The test framework no longer creates a wd.configDir whenever new test config is
set. This change simplifies the test directory structure and allows state to
persist from one test step to the next, a fundamental assumption of the test
framework.

internal/plugintest/helper.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+
+	"github.com/hashicorp/terraform-exec/tfexec"
 )
 
 const subprocessCurrentSigil = "4acd63807899403ca4859f5bb948d2c6"
@@ -107,8 +109,21 @@ func (h *Helper) NewWorkingDir() (*WorkingDir, error) {
 		return nil, err
 	}
 
+	// symlink the provider source files into the config directory
+	// e.g. testdata
+	err = symlinkDirectoriesOnly(h.sourceDir, dir)
+	if err != nil {
+		return nil, err
+	}
+
+	tf, err := tfexec.NewTerraform(dir, h.terraformExec)
+	if err != nil {
+		return nil, err
+	}
+
 	return &WorkingDir{
 		h:             h,
+		tf:            tf,
 		baseDir:       dir,
 		terraformExec: h.terraformExec,
 	}, nil

internal/plugintest/working_dir.go

@@ -13,6 +13,11 @@ import (
 	tfjson "github.com/hashicorp/terraform-json"
 )
 
+const (
+	ConfigFileName = "terraform_plugin_test.tf"
+	PlanFileName   = "tfplan"
+)
+
 // WorkingDir represents a distinct working directory that can be used for
 // running tests. Each test should construct its own WorkingDir by calling
 // NewWorkingDir or RequireNewWorkingDir on its package's singleton
@@ -26,9 +31,6 @@ type WorkingDir struct {
 	// baseArgs is arguments that should be appended to all commands
 	baseArgs []string
 
-	// configDir contains the singular config file generated for each test
-	configDir string
-
 	// tf is the instance of tfexec.Terraform used for running Terraform commands
 	tf *tfexec.Terraform
 
@@ -75,62 +77,32 @@ func (wd *WorkingDir) GetHelper() *Helper {
 	return wd.h
 }
 
-func (wd *WorkingDir) relativeConfigDir() (string, error) {
-	relPath, err := filepath.Rel(wd.baseDir, wd.configDir)
-	if err != nil {
-		return "", fmt.Errorf("Error determining relative path of configuration directory: %w", err)
-	}
-	return relPath, nil
-}
-
 // SetConfig sets a new configuration for the working directory.
 //
 // This must be called at least once before any call to Init, Plan, Apply, or
 // Destroy to establish the configuration. Any previously-set configuration is
 // discarded and any saved plan is cleared.
 func (wd *WorkingDir) SetConfig(cfg string) error {
-	// Each call to SetConfig creates a new directory under our baseDir.
-	// We create them within so that our final cleanup step will delete them
-	// automatically without any additional tracking.
-	configDir, err := ioutil.TempDir(wd.baseDir, "config")
-	if err != nil {
-		return err
-	}
-	configFilename := filepath.Join(configDir, "terraform_plugin_test.tf")
-	err = ioutil.WriteFile(configFilename, []byte(cfg), 0700)
-	if err != nil {
-		return err
-	}
-
-	// symlink the provider source files into the config directory
-	// e.g. testdata
-	err = symlinkDirectoriesOnly(wd.h.sourceDir, configDir)
-	if err != nil {
-		return err
-	}
-
-	tf, err := tfexec.NewTerraform(configDir, wd.terraformExec)
+	configFilename := filepath.Join(wd.baseDir, ConfigFileName)
+	err := ioutil.WriteFile(configFilename, []byte(cfg), 0700)
 	if err != nil {
 		return err
 	}
 
 	var mismatch *tfexec.ErrVersionMismatch
-	err = tf.SetDisablePluginTLS(true)
+	err = wd.tf.SetDisablePluginTLS(true)
 	if err != nil && !errors.As(err, &mismatch) {
 		return err
 	}
-	err = tf.SetSkipProviderVerify(true)
+	err = wd.tf.SetSkipProviderVerify(true)
 	if err != nil && !errors.As(err, &mismatch) {
 		return err
 	}
 
 	if p := os.Getenv("TF_ACC_LOG_PATH"); p != "" {
-		tf.SetLogPath(p)
+		wd.tf.SetLogPath(p)
 	}
 
-	wd.configDir = configDir
-	wd.tf = tf
-
 	// Changing configuration invalidates any saved plan.
 	err = wd.ClearPlan()
 	if err != nil {
@@ -144,7 +116,7 @@ func (wd *WorkingDir) SetConfig(cfg string) error {
 // Any remote objects tracked by the state are not destroyed first, so this
 // will leave them dangling in the remote system.
 func (wd *WorkingDir) ClearState() error {
-	err := os.Remove(filepath.Join(wd.configDir, "terraform.tfstate"))
+	err := os.Remove(filepath.Join(wd.baseDir, "terraform.tfstate"))
 	if os.IsNotExist(err) {
 		return nil
 	}
@@ -163,28 +135,32 @@ func (wd *WorkingDir) ClearPlan() error {
 // Init runs "terraform init" for the given working directory, forcing Terraform
 // to use the current version of the plugin under test.
 func (wd *WorkingDir) Init() error {
-	if wd.configDir == "" {
+	if _, err := os.Stat(wd.configFilename()); err != nil {
 		return fmt.Errorf("must call SetConfig before Init")
 	}
 
 	return wd.tf.Init(context.Background(), tfexec.Reattach(wd.reattachInfo))
 }
 
+func (wd *WorkingDir) configFilename() string {
+	return filepath.Join(wd.baseDir, ConfigFileName)
+}
+
 func (wd *WorkingDir) planFilename() string {
-	return filepath.Join(wd.configDir, "tfplan")
+	return filepath.Join(wd.baseDir, PlanFileName)
 }
 
 // CreatePlan runs "terraform plan" to create a saved plan file, which if successful
 // will then be used for the next call to Apply.
 func (wd *WorkingDir) CreatePlan() error {
-	_, err := wd.tf.Plan(context.Background(), tfexec.Reattach(wd.reattachInfo), tfexec.Refresh(false), tfexec.Out("tfplan"))
+	_, err := wd.tf.Plan(context.Background(), tfexec.Reattach(wd.reattachInfo), tfexec.Refresh(false), tfexec.Out(PlanFileName))
 	return err
 }
 
 // CreateDestroyPlan runs "terraform plan -destroy" to create a saved plan
 // file, which if successful will then be used for the next call to Apply.
 func (wd *WorkingDir) CreateDestroyPlan() error {
-	_, err := wd.tf.Plan(context.Background(), tfexec.Reattach(wd.reattachInfo), tfexec.Refresh(false), tfexec.Out("tfplan"), tfexec.Destroy(true))
+	_, err := wd.tf.Plan(context.Background(), tfexec.Reattach(wd.reattachInfo), tfexec.Refresh(false), tfexec.Out(PlanFileName), tfexec.Destroy(true))
 	return err
 }
 
@@ -195,7 +171,7 @@ func (wd *WorkingDir) CreateDestroyPlan() error {
 func (wd *WorkingDir) Apply() error {
 	args := []tfexec.ApplyOption{tfexec.Reattach(wd.reattachInfo), tfexec.Refresh(false)}
 	if wd.HasSavedPlan() {
-		args = append(args, tfexec.DirOrPlan("tfplan"))
+		args = append(args, tfexec.DirOrPlan(PlanFileName))
 	}
 
 	return wd.tf.Apply(context.Background(), args...)
@@ -260,12 +236,12 @@ func (wd *WorkingDir) State() (*tfjson.State, error) {
 
 // Import runs terraform import
 func (wd *WorkingDir) Import(resource, id string) error {
-	return wd.tf.Import(context.Background(), resource, id, tfexec.Config(wd.configDir), tfexec.Reattach(wd.reattachInfo))
+	return wd.tf.Import(context.Background(), resource, id, tfexec.Config(wd.baseDir), tfexec.Reattach(wd.reattachInfo))
 }
 
 // Refresh runs terraform refresh
 func (wd *WorkingDir) Refresh() error {
-	return wd.tf.Refresh(context.Background(), tfexec.Reattach(wd.reattachInfo), tfexec.State(filepath.Join(wd.configDir, "terraform.tfstate")))
+	return wd.tf.Refresh(context.Background(), tfexec.Reattach(wd.reattachInfo), tfexec.State(filepath.Join(wd.baseDir, "terraform.tfstate")))
 }
 
 // Schemas returns an object describing the provider schemas.