reimplement using tfexec

helper.go

@@ -194,9 +194,9 @@ func (h *Helper) NewWorkingDir() (*WorkingDir, error) {
 	}
 
 	return &WorkingDir{
-		h:        h,
-		baseArgs: []string{"-no-color"},
-		baseDir:  dir,
+		h:             h,
+		baseDir:       dir,
+		terraformExec: h.terraformExec,
 	}, nil
 }
 

working_dir.go

@@ -2,11 +2,13 @@ package tftest
 
 import (
 	"bytes"
+	"context"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 
+	"github.com/hashicorp/terraform-exec/tfexec"
 	tfjson "github.com/hashicorp/terraform-json"
 )
 
@@ -26,6 +28,12 @@ type WorkingDir struct {
 	// 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
+
+	// terraformExec is a path to a terraform binary, inherited from Helper
+	terraformExec string
+
 	env map[string]string
 }
 
@@ -81,7 +89,13 @@ func (wd *WorkingDir) SetConfig(cfg string) error {
 		return err
 	}
 
+	tf, err := tfexec.NewTerraform(configDir, wd.terraformExec)
+	if err != nil {
+		return err
+	}
+
 	wd.configDir = configDir
+	wd.tf = tf
 
 	// Changing configuration invalidates any saved plan.
 	err = wd.ClearPlan()
@@ -142,19 +156,14 @@ func (wd *WorkingDir) RequireClearPlan(t TestControl) {
 	}
 }
 
-func (wd *WorkingDir) init() error {
-	args := []string{"init", wd.configDir}
-	args = append(args, wd.baseArgs...)
-	return wd.runTerraform(nil, args...)
-}
-
 // 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 == "" {
 		return fmt.Errorf("must call SetConfig before Init")
 	}
-	return wd.init()
+
+	return wd.tf.Init(context.Background())
 }
 
 // RequireInit is a variant of Init that will fail the test via the given
@@ -174,10 +183,7 @@ func (wd *WorkingDir) planFilename() string {
 // 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 {
-	args := []string{"plan", "-refresh=false"}
-	args = append(args, wd.baseArgs...)
-	args = append(args, "-out=tfplan", wd.configDir)
-	return wd.runTerraform(nil, args...)
+	return wd.tf.Plan(context.Background(), tfexec.Refresh(false), tfexec.Out("tfplan"), tfexec.Dir(wd.configDir))
 }
 
 // RequireCreatePlan is a variant of CreatePlan that will fail the test via
@@ -195,11 +201,9 @@ func (wd *WorkingDir) RequireCreatePlan(t TestControl) {
 // this will apply the saved plan. Otherwise, it will implicitly create a new
 // plan and apply it.
 func (wd *WorkingDir) Apply() error {
-	args := []string{"apply", "-refresh=false"}
-	args = append(args, wd.baseArgs...)
-
+	args := []tfexec.ApplyOption{tfexec.Refresh(false)}
 	if wd.HasSavedPlan() {
-		args = append(args, "tfplan")
+		args = append(args, tfexec.DirOrPlan("tfplan"))
 	} else {
 		// we need to use a relative config dir here or we get an
 		// error about Terraform not having any configuration. See
@@ -209,11 +213,9 @@ func (wd *WorkingDir) Apply() error {
 		if err != nil {
 			return err
 		}
-		args = append(args, "-auto-approve")
-		args = append(args, configDir)
+		args = append(args, tfexec.DirOrPlan(configDir))
 	}
-
-	return wd.runTerraform(nil, args...)
+	return wd.tf.Apply(context.Background(), args...)
 }
 
 // RequireApply is a variant of Apply that will fail the test via
@@ -232,11 +234,7 @@ func (wd *WorkingDir) RequireApply(t TestControl) {
 // If destroy fails then remote objects might still exist, and continue to
 // exist after a particular test is concluded.
 func (wd *WorkingDir) Destroy() error {
-	args := []string{"destroy", "-refresh=false"}
-	args = append(args, wd.baseArgs...)
-
-	args = append(args, "-auto-approve", wd.configDir)
-	return wd.runTerraform(nil, args...)
+	return wd.tf.Destroy(context.Background(), tfexec.Refresh(false), tfexec.Dir(wd.configDir))
 }
 
 // RequireDestroy is a variant of Destroy that will fail the test via
@@ -271,16 +269,7 @@ func (wd *WorkingDir) SavedPlan() (*tfjson.Plan, error) {
 
 	var ret tfjson.Plan
 
-	args := []string{"show"}
-	args = append(args, wd.baseArgs...)
-	args = append(args, "-json", wd.planFilename())
-
-	err := wd.runTerraformJSON(&ret, args...)
-	if err != nil {
-		return nil, err
-	}
-
-	return &ret, nil
+	return wd.tf.Show(context.Background(), tfexec.Path(wd.planFilename()))
 }
 
 // RequireSavedPlan is a variant of SavedPlan that will fail the test via
@@ -306,11 +295,9 @@ func (wd *WorkingDir) SavedPlanStdout() (string, error) {
 
 	var ret bytes.Buffer
 
-	args := []string{"show"}
-	args = append(args, wd.baseArgs...)
-	args = append(args, wd.planFilename())
-
-	err := wd.runTerraform(&ret, args...)
+	wd.tf.SetStdout(&ret)
+	defer wd.tf.SetStdout(ioutil.Discard)
+	_, err := wd.tf.Show(context.Background(), tfexec.Plan(wd.planFilename()))
 	if err != nil {
 		return "", err
 	}
@@ -334,18 +321,7 @@ func (wd *WorkingDir) RequireSavedPlanStdout(t TestControl) string {
 //
 // If the state cannot be read, State returns an error.
 func (wd *WorkingDir) State() (*tfjson.State, error) {
-	var ret tfjson.State
-
-	args := []string{"show"}
-	args = append(args, wd.baseArgs...)
-	args = append(args, "-json")
-
-	err := wd.runTerraformJSON(&ret, args...)
-	if err != nil {
-		return nil, err
-	}
-
-	return &ret, nil
+	return wd.tf.Show(context.Background())
 }
 
 // RequireState is a variant of State that will fail the test via
@@ -362,10 +338,7 @@ func (wd *WorkingDir) RequireState(t TestControl) *tfjson.State {
 
 // Import runs terraform import
 func (wd *WorkingDir) Import(resource, id string) error {
-	args := []string{"import"}
-	args = append(args, wd.baseArgs...)
-	args = append(args, "-config="+wd.configDir, resource, id)
-	return wd.runTerraform(nil, args...)
+	return wd.tf.Import(context.Background(), resource, id, tfexec.Config(wd.configDir))
 }
 
 // RequireImport is a variant of Import that will fail the test via
@@ -380,11 +353,7 @@ func (wd *WorkingDir) RequireImport(t TestControl, resource, id string) {
 
 // Refresh runs terraform refresh
 func (wd *WorkingDir) Refresh() error {
-	args := []string{"refresh"}
-	args = append(args, wd.baseArgs...)
-	args = append(args, "-state="+filepath.Join(wd.baseDir, "terraform.tfstate"))
-	args = append(args, wd.configDir)
-	return wd.runTerraform(nil, args...)
+	return wd.tf.Refresh(context.Background(), tfexec.State(filepath.Join(wd.baseDir, "terraform.tfstate")), tfexec.Dir(wd.configDir))
 }
 
 // RequireRefresh is a variant of Refresh that will fail the test via
@@ -401,15 +370,7 @@ func (wd *WorkingDir) RequireRefresh(t TestControl) {
 //
 // If the schemas cannot be read, Schemas returns an error.
 func (wd *WorkingDir) Schemas() (*tfjson.ProviderSchemas, error) {
-	args := []string{"providers", wd.configDir, "schema"}
-
-	var ret tfjson.ProviderSchemas
-	err := wd.runTerraformJSON(&ret, args...)
-	if err != nil {
-		return nil, err
-	}
-
-	return &ret, nil
+	return wd.tf.ProvidersSchema(context.Background())
 }
 
 // RequireSchemas is a variant of Schemas that will fail the test via