ImportState: Fix panic when identity attribute is null

.changes/unreleased/BUG FIXES-20250507-174510.yaml

@@ -0,0 +1,5 @@
+kind: BUG FIXES
+body: 'ImportState: Fixes a bug where an identity attribute set to `null` would panic when testing import via identity.'
+time: 2025-05-07T17:45:10.221508-04:00
+custom:
+    Issue: "499"

helper/resource/importstate/examplecloud_test.go

@@ -479,3 +479,120 @@ func examplecloudResourceWithEveryIdentitySchemaType() testprovider.Resource {
 		},
 	}
 }
+
+func examplecloudResourceWithNullIdentityAttr() testprovider.Resource {
+	return testprovider.Resource{
+		CreateResponse: &resource.CreateResponse{
+			NewState: tftypes.NewValue(
+				tftypes.Object{
+					AttributeTypes: map[string]tftypes.Type{
+						"id":       tftypes.String,
+						"location": tftypes.String,
+						"name":     tftypes.String,
+					},
+				},
+				map[string]tftypes.Value{
+					"id":       tftypes.NewValue(tftypes.String, "westeurope/somevalue"),
+					"location": tftypes.NewValue(tftypes.String, "westeurope"),
+					"name":     tftypes.NewValue(tftypes.String, "somevalue"),
+				},
+			),
+			NewIdentity: teststep.Pointer(tftypes.NewValue(
+				tftypes.Object{
+					AttributeTypes: map[string]tftypes.Type{
+						"id":                        tftypes.String,
+						"value_we_dont_always_need": tftypes.String,
+					},
+				},
+				map[string]tftypes.Value{
+					"id":                        tftypes.NewValue(tftypes.String, "westeurope/somevalue"),
+					"value_we_dont_always_need": tftypes.NewValue(tftypes.String, nil),
+				},
+			)),
+		},
+		ReadResponse: &resource.ReadResponse{
+			NewState: tftypes.NewValue(
+				tftypes.Object{
+					AttributeTypes: map[string]tftypes.Type{
+						"id":       tftypes.String,
+						"location": tftypes.String,
+						"name":     tftypes.String,
+					},
+				},
+				map[string]tftypes.Value{
+					"id":       tftypes.NewValue(tftypes.String, "westeurope/somevalue"),
+					"location": tftypes.NewValue(tftypes.String, "westeurope"),
+					"name":     tftypes.NewValue(tftypes.String, "somevalue"),
+				},
+			),
+			NewIdentity: teststep.Pointer(tftypes.NewValue(
+				tftypes.Object{
+					AttributeTypes: map[string]tftypes.Type{
+						"id":                        tftypes.String,
+						"value_we_dont_always_need": tftypes.String,
+					},
+				},
+				map[string]tftypes.Value{
+					"id":                        tftypes.NewValue(tftypes.String, "westeurope/somevalue"),
+					"value_we_dont_always_need": tftypes.NewValue(tftypes.String, nil),
+				},
+			)),
+		},
+		ImportStateResponse: &resource.ImportStateResponse{
+			State: tftypes.NewValue(
+				tftypes.Object{
+					AttributeTypes: map[string]tftypes.Type{
+						"id":       tftypes.String,
+						"location": tftypes.String,
+						"name":     tftypes.String,
+					},
+				},
+				map[string]tftypes.Value{
+					"id":       tftypes.NewValue(tftypes.String, "westeurope/somevalue"),
+					"location": tftypes.NewValue(tftypes.String, "westeurope"),
+					"name":     tftypes.NewValue(tftypes.String, "somevalue"),
+				},
+			),
+			Identity: teststep.Pointer(tftypes.NewValue(
+				tftypes.Object{
+					AttributeTypes: map[string]tftypes.Type{
+						"id":                        tftypes.String,
+						"value_we_dont_always_need": tftypes.String,
+					},
+				},
+				map[string]tftypes.Value{
+					"id":                        tftypes.NewValue(tftypes.String, "westeurope/somevalue"),
+					"value_we_dont_always_need": tftypes.NewValue(tftypes.String, nil),
+				},
+			)),
+		},
+		SchemaResponse: &resource.SchemaResponse{
+			Schema: &tfprotov6.Schema{
+				Block: &tfprotov6.SchemaBlock{
+					Attributes: []*tfprotov6.SchemaAttribute{
+						ComputedStringAttribute("id"),
+						RequiredStringAttribute("location"),
+						RequiredStringAttribute("name"),
+					},
+				},
+			},
+		},
+		IdentitySchemaResponse: &resource.IdentitySchemaResponse{
+			Schema: &tfprotov6.ResourceIdentitySchema{
+				Version: 1,
+				IdentityAttributes: []*tfprotov6.ResourceIdentitySchemaAttribute{
+					{
+						Name:              "id",
+						Type:              tftypes.String,
+						RequiredForImport: true,
+					},
+					{
+						Name:              "value_we_dont_always_need",
+						Type:              tftypes.String,
+						OptionalForImport: true,
+					},
+				},
+			},
+		},
+	}
+}

helper/resource/importstate/import_block_with_resource_identity_test.go

@@ -11,6 +11,8 @@ import (
 
 	"github.com/hashicorp/terraform-plugin-testing/internal/testing/testprovider"
 	"github.com/hashicorp/terraform-plugin-testing/internal/testing/testsdk/providerserver"
+	"github.com/hashicorp/terraform-plugin-testing/knownvalue"
+	"github.com/hashicorp/terraform-plugin-testing/statecheck"
 	"github.com/hashicorp/terraform-plugin-testing/tfversion"
 
 	r "github.com/hashicorp/terraform-plugin-testing/helper/resource"
@@ -47,6 +49,43 @@ func TestImportBlock_WithResourceIdentity(t *testing.T) {
 	})
 }
 
+func TestImportBlock_WithResourceIdentity_NullAttribute(t *testing.T) {
+	t.Parallel()
+
+	r.UnitTest(t, r.TestCase{
+		TerraformVersionChecks: []tfversion.TerraformVersionCheck{
+			tfversion.SkipBelow(tfversion.Version1_12_0), // ImportBlockWithResourceIdentity requires Terraform 1.12.0 or later
+		},
+		ProtoV6ProviderFactories: map[string]func() (tfprotov6.ProviderServer, error){
+			"examplecloud": providerserver.NewProviderServer(testprovider.Provider{
+				Resources: map[string]testprovider.Resource{
+					"examplecloud_container": examplecloudResourceWithNullIdentityAttr(),
+				},
+			}),
+		},
+		Steps: []r.TestStep{
+			{
+				Config: `
+				resource "examplecloud_container" "test" {
+					location = "westeurope"
+					name     = "somevalue"
+				}`,
+				ConfigStateChecks: []statecheck.StateCheck{
+					statecheck.ExpectIdentity("examplecloud_container.test", map[string]knownvalue.Check{
+						"id":                        knownvalue.StringExact("westeurope/somevalue"),
+						"value_we_dont_always_need": knownvalue.Null(), // This value will not be brought over to import config
+					}),
+				},
+			},
+			{
+				ResourceName:    "examplecloud_container.test",
+				ImportState:     true,
+				ImportStateKind: r.ImportBlockWithResourceIdentity,
+			},
+		},
+	})
+}
+
 func TestImportBlock_WithResourceIdentity_WithEveryType(t *testing.T) {
 	t.Parallel()
 

helper/resource/testing_new_import_state.go

@@ -445,6 +445,11 @@ func appendImportBlockWithIdentity(config teststep.Config, resourceName string,
 		resourceName))
 
 	for k, v := range identityValues {
+		// It's valid for identity attributes to be null, we can just omit it from config
+		if v == nil {
+			continue
+		}
+
 		switch v := v.(type) {
 		case bool:
 			configBuilder.WriteString(fmt.Sprintf(`		%q = %t`+"\n", k, v))