Add resource name_from_id provider-defined function (#10106)

* Add `name_from_id` function, tests, docs

* Fix whitespace in acc tests' HCL config

* Skip provider-defined acceptance test in VCR, as VCR system doesn't use required Terraform version yet

* Update documentation examples to meet feedback given in #10060

* Update `name_from_id` acc tests to not use networking-related resources

* Update mmv1/third_party/terraform/functions/name_from_id_test.go

mmv1/third_party/terraform/functions/name_from_id.go

@@ -0,0 +1,59 @@
+package functions
+
+import (
+	"context"
+	"regexp"
+
+	"github.com/hashicorp/terraform-plugin-framework/function"
+)
+
+var _ function.Function = NameFromIdFunction{}
+
+func NewNameFromIdFunction() function.Function {
+	return &NameFromIdFunction{}
+}
+
+type NameFromIdFunction struct{}
+
+func (f NameFromIdFunction) Metadata(ctx context.Context, req function.MetadataRequest, resp *function.MetadataResponse) {
+	resp.Name = "name_from_id"
+}
+
+func (f NameFromIdFunction) Definition(ctx context.Context, req function.DefinitionRequest, resp *function.DefinitionResponse) {
+	resp.Definition = function.Definition{
+		Summary:     "Returns the short-form name of a resource within a provided resource's id, resource URI, self link, or full resource name.",
+		Description: "Takes a single string argument, which should be a resource's id, resource URI, self link, or full resource name. This function will return the short-form name of a resource from the input string, or raise an error due to a problem with the input string. The function returns the final element in the input string as the resource's name, e.g. when the function is passed the id \"projects/my-project/zones/us-central1-c/instances/my-instance\" as an argument it will return \"my-instance\".",
+		Parameters: []function.Parameter{
+			function.StringParameter{
+				Name:        "id",
+				Description: "A string of a resource's id, resource URI, self link, or full resource name. For example, \"projects/my-project/zones/us-central1-c/instances/my-instance\", \"https://www.googleapis.com/compute/v1/projects/my-project/zones/us-central1-c/instances/my-instance\" and \"//gkehub.googleapis.com/projects/my-project/locations/us-central1/memberships/my-membership\" are valid values",
+			},
+		},
+		Return: function.StringReturn{},
+	}
+}
+
+func (f NameFromIdFunction) Run(ctx context.Context, req function.RunRequest, resp *function.RunResponse) {
+	// Load arguments from function call
+	var arg0 string
+	resp.Diagnostics.Append(req.Arguments.GetArgument(ctx, 0, &arg0)...)
+
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	// Prepare how we'll identify resource name from input string
+	regex := regexp.MustCompile("/(?P<ResourceName>[^/]+)$") // Should match the pattern below
+	template := "$ResourceName"                              // Should match the submatch identifier in the regex
+	pattern := "resourceType/{name}$"                        // Human-readable pseudo-regex pattern used in errors and warnings
+
+	// Validate input
+	ValidateElementFromIdArguments(arg0, regex, pattern, resp)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	// Get and return element from input string
+	name := GetElementFromId(arg0, regex, template)
+	resp.Diagnostics.Append(resp.Result.Set(ctx, name)...)
+}

mmv1/third_party/terraform/functions/name_from_id_internal_test.go

@@ -0,0 +1,97 @@
+package functions
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/hashicorp/terraform-plugin-framework/attr"
+	"github.com/hashicorp/terraform-plugin-framework/diag"
+	"github.com/hashicorp/terraform-plugin-framework/function"
+	"github.com/hashicorp/terraform-plugin-framework/types"
+	"github.com/hashicorp/terraform-plugin-framework/types/basetypes"
+)
+
+func TestFunctionRun_name_from_id(t *testing.T) {
+	t.Parallel()
+
+	name := "foobar"
+
+	// Happy path inputs
+	validId := fmt.Sprintf("projects/my-project/zones/us-central1-c/instances/%s", name)
+	validSelfLink := fmt.Sprintf("https://www.googleapis.com/compute/v1/%s", validId)
+	validOpStyleResourceName := fmt.Sprintf("//gkehub.googleapis.com/projects/my-project/locations/us-central1/memberships/%s", name)
+
+	// Unhappy path inputs
+	invalidInput := "this isn't a URI or id"
+
+	testCases := map[string]struct {
+		request  function.RunRequest
+		expected function.RunResponse
+	}{
+		"it returns the expected output value when given a valid resource id input": {
+			request: function.RunRequest{
+				Arguments: function.NewArgumentsData([]attr.Value{types.StringValue(validId)}),
+			},
+			expected: function.RunResponse{
+				Result: function.NewResultData(types.StringValue(name)),
+			},
+		},
+		"it returns the expected output value when given a valid resource self_link input": {
+			request: function.RunRequest{
+				Arguments: function.NewArgumentsData([]attr.Value{types.StringValue(validSelfLink)}),
+			},
+			expected: function.RunResponse{
+				Result: function.NewResultData(types.StringValue(name)),
+			},
+		},
+		"it returns the expected output value when given a valid OP style resource name input": {
+			request: function.RunRequest{
+				Arguments: function.NewArgumentsData([]attr.Value{types.StringValue(validOpStyleResourceName)}),
+			},
+			expected: function.RunResponse{
+				Result: function.NewResultData(types.StringValue(name)),
+			},
+		},
+		"it returns an error when given input with no submatches": {
+			request: function.RunRequest{
+				Arguments: function.NewArgumentsData([]attr.Value{types.StringValue(invalidInput)}),
+			},
+			expected: function.RunResponse{
+				Result: function.NewResultData(types.StringNull()),
+				Diagnostics: diag.Diagnostics{
+					diag.NewArgumentErrorDiagnostic(
+						0,
+						noMatchesErrorSummary,
+						fmt.Sprintf("The input string \"%s\" doesn't contain the expected pattern \"resourceType/{name}$\".", invalidInput),
+					),
+				},
+			},
+		},
+	}
+
+	for name, testCase := range testCases {
+		tn, tc := name, testCase
+
+		t.Run(tn, func(t *testing.T) {
+			t.Parallel()
+
+			// Arrange
+			got := function.RunResponse{
+				Result: function.NewResultData(basetypes.StringValue{}),
+			}
+
+			// Act
+			NewNameFromIdFunction().Run(context.Background(), tc.request, &got)
+
+			// Assert
+			if diff := cmp.Diff(got.Result, tc.expected.Result); diff != "" {
+				t.Errorf("unexpected diff between expected and received result: %s", diff)
+			}
+			if diff := cmp.Diff(got.Diagnostics, tc.expected.Diagnostics); diff != "" {
+				t.Errorf("unexpected diff between expected and received diagnostics: %s", diff)
+			}
+		})
+	}
+}

mmv1/third_party/terraform/functions/name_from_id_test.go

@@ -0,0 +1,88 @@
+package functions_test
+
+import (
+	"fmt"
+	"regexp"
+	"testing"
+
+	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/resource"
+	"github.com/hashicorp/terraform-provider-google/google/acctest"
+)
+
+func TestAccProviderFunction_name_from_id(t *testing.T) {
+	t.Parallel()
+	// Skipping due to requiring TF 1.8.0 in VCR systems : https://github.com/hashicorp/terraform-provider-google/issues/17451
+	acctest.SkipIfVcr(t)
+
+	context := map[string]interface{}{
+		"function_name": "name_from_id",
+		"output_name":   "name",
+		"resource_name": fmt.Sprintf("tf-test-name-id-func-%s", acctest.RandString(t, 10)),
+	}
+
+	nameRegex := regexp.MustCompile(fmt.Sprintf("^%s$", context["resource_name"]))
+
+	acctest.VcrTest(t, resource.TestCase{
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories(t),
+		Steps: []resource.TestStep{
+			{
+				// Can get the project from a resource's id in one step
+				// Uses google_pubsub_topic resource's id attribute with format projects/{{project}}/topics/{{name}}
+				Config: testProviderFunction_get_project_from_resource_id(context),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestMatchOutput(context["output_name"].(string), nameRegex),
+				),
+			},
+			{
+				// Can get the project from a resource's self_link in one step
+				// Uses google_compute_disk resource's self_link attribute
+				Config: testProviderFunction_get_project_from_resource_self_link(context),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestMatchOutput(context["output_name"].(string), nameRegex),
+				),
+			},
+		},
+	})
+}
+
+func testProviderFunction_get_name_from_resource_id(context map[string]interface{}) string {
+	return acctest.Nprintf(`
+# terraform block required for provider function to be found
+terraform {
+  required_providers {
+    google = {
+      source = "hashicorp/google"
+    }
+  }
+}
+
+resource "google_pubsub_topic" "default" {
+  name = "%{resource_name}"
+}
+
+output "%{output_name}" {
+  value = provider::google::%{function_name}(google_pubsub_topic.default.id)
+}
+`, context)
+}
+
+func testProviderFunction_get_name_from_resource_self_link(context map[string]interface{}) string {
+	return acctest.Nprintf(`
+# terraform block required for provider function to be found
+terraform {
+  required_providers {
+    google = {
+      source = "hashicorp/google"
+    }
+  }
+}
+
+resource "google_compute_disk" "default" {
+  name  = "%{resource_name}"
+}
+
+output "%{output_name}" {
+  value = provider::google::%{function_name}(google_compute_disk.default.self_link)
+}
+`, context)
+}

mmv1/third_party/terraform/fwprovider/framework_provider.go.erb

@@ -303,10 +303,11 @@ func (p *FrameworkProvider) Resources(_ context.Context) []func() resource.Resou
 // Functions defines the provider functions implemented in the provider.
 func (p *FrameworkProvider) Functions(_ context.Context) []func() function.Function {
 	return []func() function.Function{
-		functions.NewProjectFromIdFunction,
-        functions.NewRegionFromZoneFunction,
 		functions.NewLocationFromIdFunction,
+		functions.NewNameFromIdFunction,
+		functions.NewProjectFromIdFunction,
 		functions.NewRegionFromIdFunction,
+		functions.NewRegionFromZoneFunction,
 		functions.NewZoneFromIdFunction,
 	}
 }

mmv1/third_party/terraform/website/docs/functions/name_from_id.html.markdown

@@ -0,0 +1,70 @@
+---
+page_title: name_from_id Function - terraform-provider-google
+description: |-
+  Returns the project within a provided resource id, self link, or OP style resource name.
+---
+
+# Function: name_from_id
+
+Returns the short-form name within a provided resource's id, resource URI, self link, or full resource name.
+
+For more information about using provider-defined functions with Terraform [see the official documentation](https://developer.hashicorp.com/terraform/plugin/framework/functions/concepts).
+
+## Example Usage
+
+### Use with the `google` provider
+
+```terraform
+terraform {
+  required_providers {
+    google = {
+      source = "hashicorp/google"
+    }
+  }
+}
+
+resource "google_pubsub_topic" "default" {
+  name = "my-topic"
+}
+
+# Value is "my-topic"
+output "function_output" {
+  value = provider::google::name_from_id(google_pubsub_topic.default.id)
+}
+```
+
+### Use with the `google-beta` provider
+
+```terraform
+terraform {
+  required_providers {
+    google-beta = {
+      source = "hashicorp/google-beta"
+    }
+  }
+}
+
+resource "google_pubsub_topic" "default" {
+  # provider argument omitted - provisioning by google or google-beta doesn't impact this example
+  name = "my-topic"
+}
+
+# Value is "my-topic"
+output "function_output" {
+  value = provider::google-beta::name_from_id(google_pubsub_topic.default.id)
+}
+```
+
+## Signature
+
+```text
+name_from_id(id string) string
+```
+
+## Arguments
+
+1. `id` (String) A string of a resource's id, resource URI, self link, or full resource name. For example, these are all valid values:
+
+* `"projects/my-project/zones/us-central1-c/instances/my-instance"`
+* `"https://www.googleapis.com/compute/v1/projects/my-project/zones/us-central1-c/instances/my-instance"`
+* `"//gkehub.googleapis.com/projects/my-project/locations/us-central1/memberships/my-membership"`