importstate: Fixed bug where prior test config is not used for ConfigFile or ConfigDirectory (#522)

* test config fix

* add changelog

* swap the statements around

* adjusted changelog

Author: austinvalle

.changes/unreleased/BUG FIXES-20250606-110444.yaml

@@ -0,0 +1,5 @@
+kind: BUG FIXES
+body: 'helper/resource: Fixed bug with import state mode where prior test config is not used for `ConfigFile` or `ConfigDirectory`'
+time: 2025-06-06T11:04:44.925152-04:00
+custom:
+    Issue: "516"

helper/resource/importstate/import_block_in_config_directory_test.go

@@ -38,7 +38,6 @@ func TestImportBlock_InConfigDirectory(t *testing.T) {
 				ResourceName:    "examplecloud_container.test",
 				ImportState:     true,
 				ImportStateKind: r.ImportBlockWithID,
-				ConfigDirectory: config.StaticDirectory(`testdata/2`),
 			},
 		},
 	})

helper/resource/importstate/import_block_in_config_file_test.go

@@ -38,7 +38,6 @@ func TestImportBlock_InConfigFile(t *testing.T) {
 				ResourceName:    "examplecloud_container.test",
 				ImportState:     true,
 				ImportStateKind: r.ImportBlockWithID,
-				ConfigFile:      config.StaticFile(`testdata/2/examplecloud_container.tf`),
 			},
 		},
 	})

helper/resource/importstate/import_command_with_id_test.go

@@ -11,6 +11,7 @@ import (
 	"github.com/hashicorp/terraform-plugin-go/tfprotov6"
 	"github.com/hashicorp/terraform-plugin-go/tftypes"
 
+	"github.com/hashicorp/terraform-plugin-testing/config"
 	r "github.com/hashicorp/terraform-plugin-testing/helper/resource"
 	"github.com/hashicorp/terraform-plugin-testing/internal/testing/testprovider"
 	"github.com/hashicorp/terraform-plugin-testing/internal/testing/testsdk/datasource"
@@ -197,6 +198,60 @@ func TestImportCommand_ImportStateVerify(t *testing.T) {
 	})
 }
 
+func TestImportCommand_InConfigFile(t *testing.T) {
+	t.Parallel()
+
+	r.UnitTest(t, r.TestCase{
+		TerraformVersionChecks: []tfversion.TerraformVersionCheck{
+			tfversion.SkipBelow(tfversion.Version1_0_0), // ProtoV6ProviderFactories
+		},
+		ProtoV6ProviderFactories: map[string]func() (tfprotov6.ProviderServer, error){
+			"examplecloud": providerserver.NewProviderServer(testprovider.Provider{
+				Resources: map[string]testprovider.Resource{
+					"examplecloud_container": examplecloudResource(),
+				},
+			}),
+		},
+		Steps: []r.TestStep{
+			{
+				ConfigFile: config.StaticFile(`testdata/1/examplecloud_container.tf`),
+			},
+			{
+				ResourceName:      "examplecloud_container.test",
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+		},
+	})
+}
+
+func TestImportCommand_InConfigDirectory(t *testing.T) {
+	t.Parallel()
+
+	r.UnitTest(t, r.TestCase{
+		TerraformVersionChecks: []tfversion.TerraformVersionCheck{
+			tfversion.SkipBelow(tfversion.Version1_0_0), // ProtoV6ProviderFactories
+		},
+		ProtoV6ProviderFactories: map[string]func() (tfprotov6.ProviderServer, error){
+			"examplecloud": providerserver.NewProviderServer(testprovider.Provider{
+				Resources: map[string]testprovider.Resource{
+					"examplecloud_container": examplecloudResource(),
+				},
+			}),
+		},
+		Steps: []r.TestStep{
+			{
+				ConfigDirectory: config.StaticDirectory(`testdata/1`),
+			},
+			{
+				ResourceName:      "examplecloud_container.test",
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+		},
+	})
+}
+
 func TestImportCommand_ImportStateVerify_Ignore(t *testing.T) {
 	t.Parallel()
 

helper/resource/testing_new.go

@@ -131,7 +131,7 @@ func runNewTest(ctx context.Context, t testing.T, c TestCase, helper *plugintest
 
 	// use this to track last step successfully applied
 	// acts as default for import tests
-	var appliedCfg string
+	var appliedCfg teststep.Config
 	var stepNumber int
 
 	for stepIndex, step := range c.Steps {
@@ -418,7 +418,7 @@ func runNewTest(ctx context.Context, t testing.T, c TestCase, helper *plugintest
 				}
 			}
 
-			appliedCfg, err = step.mergedConfig(ctx, c, hasTerraformBlock, hasProviderBlock, helper.TerraformVersion())
+			mergedConfig, err := step.mergedConfig(ctx, c, hasTerraformBlock, hasProviderBlock, helper.TerraformVersion())
 
 			if err != nil {
 				logging.HelperResourceError(ctx,
@@ -428,6 +428,19 @@ func runNewTest(ctx context.Context, t testing.T, c TestCase, helper *plugintest
 				t.Fatalf("Error generating merged configuration: %s", err)
 			}
 
+			// Preserve the step config for future test steps to use (import state)
+			confRequest := teststep.PrepareConfigurationRequest{
+				Directory: step.ConfigDirectory,
+				File:      step.ConfigFile,
+				Raw:       mergedConfig,
+				TestStepConfigRequest: config.TestStepConfigRequest{
+					StepNumber: stepNumber,
+					TestName:   t.Name(),
+				},
+			}.Exec()
+
+			appliedCfg = teststep.Configuration(confRequest)
+
 			logging.HelperResourceDebug(ctx, "Finished TestStep")
 
 			continue

helper/resource/testing_new_import_state.go

@@ -25,7 +25,7 @@ import (
 	"github.com/hashicorp/terraform-plugin-testing/tfversion"
 )
 
-func testStepNewImportState(ctx context.Context, t testing.T, helper *plugintest.Helper, testCaseWorkingDir *plugintest.WorkingDir, step TestStep, cfgRaw string, providers *providerFactories, stepNumber int) error {
+func testStepNewImportState(ctx context.Context, t testing.T, helper *plugintest.Helper, testCaseWorkingDir *plugintest.WorkingDir, step TestStep, priorStepCfg teststep.Config, providers *providerFactories, stepNumber int) error {
 	t.Helper()
 
 	// step.ImportStateKind implicitly defaults to the zero-value (ImportCommandWithID) for backward compatibility
@@ -105,23 +105,28 @@ func testStepNewImportState(ctx context.Context, t testing.T, helper *plugintest
 		}
 	}
 
-	var inlineConfig string
-	if step.Config != "" {
-		inlineConfig = step.Config
-	} else {
-		inlineConfig = cfgRaw
-	}
 	testStepConfigRequest := config.TestStepConfigRequest{
 		StepNumber: stepNumber,
 		TestName:   t.Name(),
 	}
 	testStepConfig := teststep.Configuration(teststep.PrepareConfigurationRequest{
 		Directory:             step.ConfigDirectory,
 		File:                  step.ConfigFile,
-		Raw:                   inlineConfig,
+		Raw:                   step.Config,
 		TestStepConfigRequest: testStepConfigRequest,
 	}.Exec())
 
+	// If the current import state test step doesn't have configuration, use the prior test step config
+	if testStepConfig == nil {
+		if priorStepCfg == nil {
+			t.Fatal("Cannot import state with no specified config")
+		}
+
+		logging.HelperResourceTrace(ctx, "Using prior TestStep Config for import")
+
+		testStepConfig = priorStepCfg
+	}
+
 	switch {
 	case step.ImportStateConfigExact:
 		break
@@ -133,10 +138,6 @@ func testStepNewImportState(ctx context.Context, t testing.T, helper *plugintest
 		testStepConfig = appendImportBlock(testStepConfig, resourceName, importId)
 	}
 
-	if testStepConfig == nil {
-		t.Fatal("Cannot import state with no specified config")
-	}
-
 	var workingDir *plugintest.WorkingDir
 	if importStatePersist {
 		workingDir = testCaseWorkingDir