importstate: Use ExpectNonEmptyPlan field to ignore no-op assertion for import block test kinds

.changes/unreleased/BUG FIXES-20250602-073221.yaml

@@ -0,0 +1,5 @@
+kind: BUG FIXES
+body: 'helper/resource: Updated `ImportBlockWith*` import state modes to use the `ExpectNonEmpty` field to allow non-empty import plans to pass successfully.'
+time: 2025-06-02T07:32:21.384247-04:00
+custom:
+    Issue: "518"

helper/resource/importstate/import_block_with_id_test.go

@@ -99,6 +99,58 @@ func TestImportBlock_WithID_ExpectError(t *testing.T) {
 	})
 }
 
+func TestImportBlock_WithID_ExpectNonEmptyPlan(t *testing.T) {
+	t.Parallel()
+
+	r.UnitTest(t, r.TestCase{
+		TerraformVersionChecks: []tfversion.TerraformVersionCheck{
+			tfversion.SkipBelow(tfversion.Version1_5_0), // ImportBlockWithID requires Terraform 1.5.0 or later
+		},
+		ProtoV6ProviderFactories: map[string]func() (tfprotov6.ProviderServer, error){
+			"examplecloud": providerserver.NewProviderServer(testprovider.Provider{
+				Resources: map[string]testprovider.Resource{
+					"examplecloud_container": examplecloudResource(),
+				},
+			}),
+		},
+		Steps: []r.TestStep{
+			{
+				Config: `
+				resource "examplecloud_container" "test" {
+					location = "westeurope"
+					name     = "somevalue"
+				}`,
+			},
+			{
+				Config: `
+				resource "examplecloud_container" "test" {
+					location = "eastus"
+					name     = "somevalue"
+				}
+
+				import {
+					to = examplecloud_container.test
+					id = "westeurope/somevalue"
+				}
+				`,
+				ResourceName:           "examplecloud_container.test",
+				ImportState:            true,
+				ImportStateKind:        r.ImportBlockWithID,
+				ImportStateConfigExact: true,
+				ExpectNonEmptyPlan:     true,
+				ImportPlanChecks: r.ImportPlanChecks{
+					PreApply: []plancheck.PlanCheck{
+						plancheck.ExpectResourceAction("examplecloud_container.test", plancheck.ResourceActionUpdate),
+						// The location address is imported as "westeurope/somevalue", which will be updated by the config to "eastus"
+						plancheck.ExpectKnownValue("examplecloud_container.test", tfjsonpath.New("location"), knownvalue.StringExact("eastus")),
+						plancheck.ExpectUnknownValue("examplecloud_container.test", tfjsonpath.New("id")),
+					},
+				},
+			},
+		},
+	})
+}
+
 func TestImportBlock_WithID_FailWhenNotSupported(t *testing.T) {
 	t.Parallel()
 

helper/resource/testing.go

@@ -674,6 +674,11 @@ type TestStep struct {
 	// ID of that resource.
 	ImportState bool
 
+	// ImportStateKind controls the method of import that is used in combination with the other import-related fields on the TestStep struct.
+	//
+	//   - By default, ImportCommandWithID is used, which tests import by using the ID string with the `terraform import` command. This was the original behavior prior to introducing the ImportStateKind field.
+	//   - ImportBlockWithID tests import by using the ID string in an import configuration block with the `terraform plan` command.
+	//   - ImportBlockWithResourceIdentity imports the state using an import configuration block with a resource identity.
 	ImportStateKind ImportStateKind
 
 	// ImportStateId is the ID to perform an ImportState operation with.

helper/resource/testing_new_import_state.go

@@ -221,8 +221,9 @@ func testImportBlock(ctx context.Context, t testing.T, workingDir *plugintest.Wo
 	switch {
 	case importing == nil:
 		return fmt.Errorf("importing resource %s: expected an import operation, got %q action with plan \nstdout:\n\n%s", resourceChangeUnderTest.Address, actions, savedPlanRawStdout(ctx, t, workingDir, providers))
-
-	case !actions.NoOp():
+	// By default we want to ensure there isn't a proposed plan after importing, but for some resources this is unavoidable.
+	// An example would be importing a resource that cannot read it's entire value back from the remote API.
+	case !step.ExpectNonEmptyPlan && !actions.NoOp():
 		return fmt.Errorf("importing resource %s: expected a no-op import operation, got %q action with plan \nstdout:\n\n%s", resourceChangeUnderTest.Address, actions, savedPlanRawStdout(ctx, t, workingDir, providers))
 	}