@@customeAzureResource decorator for resources that doesn't use the base resource types

.chronus/changes/new-decorator-custom-azure-resource-2024-10-27-15-43-13.md

@@ -0,0 +1,7 @@
+---
+changeKind: feature
+packages:
+  - "@azure-tools/typespec-azure-resource-manager"
+---
+
+Add the `@Azure.ResourceManager.Legacy.customAzureResource` decorator to identify ARM resources that do not use the base resource types.

.chronus/changes/new-decorator-custom-azure-resource-2024-11-5-11-0-40.md

@@ -0,0 +1,7 @@
+---
+changeKind: feature
+packages:
+  - "@azure-tools/typespec-azure-rulesets"
+---
+
+Discourage usage of new decorator `@Azure.ResourceManager.Legacy.customAzureResource`

packages/typespec-azure-resource-manager/README.md

@@ -42,6 +42,7 @@ Available ruleSets:
 | `@azure-tools/typespec-azure-resource-manager/arm-resource-operation-response`                                                                                                                           | [RPC 008]: PUT, GET, PATCH & LIST must return the same resource schema.                                                                                                                                                                              |
 | `@azure-tools/typespec-azure-resource-manager/arm-resource-path-segment-invalid-chars`                                                                                                                   | Arm resource name must contain only alphanumeric characters.                                                                                                                                                                                         |
 | `@azure-tools/typespec-azure-resource-manager/arm-resource-provisioning-state`                                                                                                                           | Check for properly configured provisioningState property.                                                                                                                                                                                            |
+| `@azure-tools/typespec-azure-resource-manager/arm-custom-resource-usage-discourage`                                                                                                                      | Verify the usage of @customAzureResource decorator.                                                                                                                                                                                                  |
 | `@azure-tools/typespec-azure-resource-manager/beyond-nesting-levels`                                                                                                                                     | Tracked Resources must use 3 or fewer levels of nesting.                                                                                                                                                                                             |
 | `@azure-tools/typespec-azure-resource-manager/arm-resource-operation`                                                                                                                                    | Validate ARM Resource operations.                                                                                                                                                                                                                    |
 | `@azure-tools/typespec-azure-resource-manager/no-resource-delete-operation`                                                                                                                              | Check for resources that must have a delete operation.                                                                                                                                                                                               |
@@ -496,3 +497,24 @@ This allows sharing Azure Resource Manager resource types across specifications
 | Name       | Type          | Description                                                              |
 | ---------- | ------------- | ------------------------------------------------------------------------ |
 | namespaces | `Namespace[]` | The namespaces of Azure Resource Manager libraries used in this provider |
+
+### Azure.ResourceManager.Legacy
+
+- [`@customAzureResource`](#@customazureresource)
+
+#### `@customAzureResource`
+
+This decorator is used on resources that do not satisfy the definition of a resource
+but need to be identified as such.
+
+```typespec
+@Azure.ResourceManager.Legacy.customAzureResource
+```
+
+##### Target
+
+`Model`
+
+##### Parameters
+
+None

packages/typespec-azure-resource-manager/generated-defs/Azure.ResourceManager.ts

@@ -249,6 +249,12 @@ export type ArmCommonTypesVersionDecorator = (
  */
 export type ArmVirtualResourceDecorator = (context: DecoratorContext, target: Model) => void;
 
+/**
+ *  This decorator is used on resources that do not satisfy the definition of a resource
+ *  but need to be identified as such.
+ */
+export type CustomAzureResourceDecorator = (context: DecoratorContext, target: Model) => void;
+
 /**
  * This decorator sets the base type of the given resource.
  *
@@ -283,3 +289,7 @@ export type AzureResourceManagerDecorators = {
   armVirtualResource: ArmVirtualResourceDecorator;
   resourceBaseType: ResourceBaseTypeDecorator;
 };
+
+export type AzureResourceManagerLegacyDecorators = {
+  customAzureResource: CustomAzureResourceDecorator;
+};

packages/typespec-azure-resource-manager/lib/Legacy/arm.legacy.tsp

@@ -1 +1,2 @@
 import "./managed-identity.tsp";
+import "./decorator.tsp";

packages/typespec-azure-resource-manager/lib/Legacy/decorator.tsp

@@ -0,0 +1,9 @@
+using TypeSpec.Reflection;
+
+namespace Azure.ResourceManager.Legacy;
+
+/**
+ * This decorator is used on resources that do not satisfy the definition of a resource
+ * but need to be identified as such.
+ */
+extern dec customAzureResource(target: Model);

packages/typespec-azure-resource-manager/src/linter.ts

@@ -1,5 +1,6 @@
 import { defineLinter } from "@typespec/compiler";
 import { armCommonTypesVersionRule } from "./rules/arm-common-types-version.js";
+import { armCustomResourceUsageDiscourage } from "./rules/arm-custom-resource-usage-discourage.js";
 import { armDeleteResponseCodesRule } from "./rules/arm-delete-response-codes.js";
 import { armNoRecordRule } from "./rules/arm-no-record.js";
 import { armPostResponseCodesRule } from "./rules/arm-post-response-codes.js";
@@ -46,6 +47,7 @@ const rules = [
   armResourceOperationsRule,
   armResourcePathInvalidCharsRule,
   armResourceProvisioningStateRule,
+  armCustomResourceUsageDiscourage,
   beyondNestingRule,
   coreOperationsRule,
   deleteOperationMissingRule,

packages/typespec-azure-resource-manager/src/operations.ts

@@ -33,6 +33,7 @@ import {
   getArmResourceInfo,
   getResourceBaseType,
   isArmVirtualResource,
+  isCustomAzureResource,
   ResourceBaseType,
 } from "./resource.js";
 import { ArmStateKeys } from "./state.js";
@@ -234,8 +235,11 @@ export function armRenameListByOperationInternal(
     [parentTypeName, parentFriendlyTypeName] = getArmParentName(context.program, resourceType);
   }
   const parentType = getParentResource(program, resourceType);
-
-  if (parentType && !isArmVirtualResource(program, parentType)) {
+  if (
+    parentType &&
+    !isArmVirtualResource(program, parentType) &&
+    !isCustomAzureResource(program, parentType)
+  ) {
     const parentResourceInfo = getArmResourceInfo(program, parentType);
     if (
       !parentResourceInfo &&
@@ -278,7 +282,7 @@ export function armRenameListByOperationInternal(
 
 function getArmParentName(program: Program, resource: Model): string[] {
   const parent = getParentResource(program, resource);
-  if (parent && isArmVirtualResource(program, parent)) {
+  if (parent && (isArmVirtualResource(program, parent) || isCustomAzureResource(program, parent))) {
     const parentName = getFriendlyName(program, parent) ?? parent.name;
     if (parentName === undefined || parentName.length < 2) {
       return ["", ""];

packages/typespec-azure-resource-manager/src/private.decorators.ts

@@ -40,6 +40,7 @@ import {
   getArmResourceKind,
   getResourceBaseType,
   isArmVirtualResource,
+  isCustomAzureResource,
   resolveResourceBaseType,
 } from "./resource.js";
 import { ArmStateKeys } from "./state.js";
@@ -325,6 +326,7 @@ const $armResourceInternal: ArmResourceInternalDecorator = (
 
   let kind = getArmResourceKind(resourceType);
   if (isArmVirtualResource(program, resourceType)) kind = "Virtual";
+  if (isCustomAzureResource(program, resourceType)) kind = "Custom";
   if (!kind) {
     reportDiagnostic(program, {
       code: "arm-resource-invalid-base-type",

packages/typespec-azure-resource-manager/src/resource.ts

@@ -20,6 +20,7 @@ import {
   ArmProviderNameValueDecorator,
   ArmResourceOperationsDecorator,
   ArmVirtualResourceDecorator,
+  CustomAzureResourceDecorator,
   ExtensionResourceDecorator,
   LocationResourceDecorator,
   ResourceBaseTypeDecorator,
@@ -34,7 +35,7 @@ import { ArmResourceOperations, resolveResourceOperations } from "./operations.j
 import { getArmResource, listArmResources } from "./private.decorators.js";
 import { ArmStateKeys } from "./state.js";
 
-export type ArmResourceKind = "Tracked" | "Proxy" | "Extension" | "Virtual";
+export type ArmResourceKind = "Tracked" | "Proxy" | "Extension" | "Virtual" | "Custom";
 
 /**
  * Interface for ARM resource detail base.
@@ -92,6 +93,16 @@ export const $armVirtualResource: ArmVirtualResourceDecorator = (
   }
 };
 
+export const $customAzureResource: CustomAzureResourceDecorator = (
+  context: DecoratorContext,
+  entity: Model,
+) => {
+  const { program } = context;
+  if (isTemplateDeclaration(entity)) return;
+
+  program.stateMap(ArmStateKeys.customAzureResource).set(entity, "Custom");
+};
+
 function getProperty(
   target: Model,
   predicate: (property: ModelProperty) => boolean,
@@ -114,6 +125,18 @@ export function isArmVirtualResource(program: Program, target: Model): boolean {
   return false;
 }
 
+/**
+ * Determine if the given model is a custom resource.
+ * @param program The program to process.
+ * @param target The model to check.
+ * @returns true if the model or any model it extends is marked as a resource, otherwise false.
+ */
+export function isCustomAzureResource(program: Program, target: Model): boolean {
+  if (program.stateMap(ArmStateKeys.customAzureResource).has(target)) return true;
+  if (target.baseModel) return isCustomAzureResource(program, target.baseModel);
+  return false;
+}
+
 function resolveArmResourceDetails(
   program: Program,
   resource: ArmResourceDetailsBase,

packages/typespec-azure-resource-manager/src/rules/arm-custom-resource-usage-discourage.ts

@@ -0,0 +1,23 @@
+import { createRule, Model } from "@typespec/compiler";
+import { isCustomAzureResource } from "../resource.js";
+
+export const armCustomResourceUsageDiscourage = createRule({
+  name: "arm-custom-resource-usage-discourage",
+  severity: "warning",
+  description: "Verify the usage of @customAzureResource decorator.",
+  messages: {
+    default: `Avoid using this decorator except when converting old APIs to TypeSpec, as it does not provide validation for ARM resources.`,
+  },
+  create(context) {
+    return {
+      model: (model: Model) => {
+        if (isCustomAzureResource(context.program, model)) {
+          context.reportDiagnostic({
+            code: "arm-custom-resource-usage-discourage",
+            target: model,
+          });
+        }
+      },
+    };
+  },
+});

packages/typespec-azure-resource-manager/src/state.ts

@@ -20,6 +20,7 @@ export const ArmStateKeys = {
   armSingletonResources: azureResourceManagerCreateStateSymbol("armSingletonResources"),
   resourceBaseType: azureResourceManagerCreateStateSymbol("resourceBaseTypeKey"),
   armBuiltInResource: azureResourceManagerCreateStateSymbol("armExternalResource"),
+  customAzureResource: azureResourceManagerCreateStateSymbol("azureCustomResource"),
 
   // private.decorator.ts
   azureResourceBase: azureResourceManagerCreateStateSymbol("azureResourceBase"),

packages/typespec-azure-resource-manager/src/tsp-index.ts

@@ -1,5 +1,8 @@
 import { definePackageFlags } from "@typespec/compiler";
-import { AzureResourceManagerDecorators } from "../generated-defs/Azure.ResourceManager.js";
+import {
+  AzureResourceManagerDecorators,
+  AzureResourceManagerLegacyDecorators,
+} from "../generated-defs/Azure.ResourceManager.js";
 import { $armCommonTypesVersion } from "./common-types.js";
 import { $armLibraryNamespace, $armProviderNamespace, $useLibraryNamespace } from "./namespace.js";
 import {
@@ -15,6 +18,7 @@ import {
   $armProviderNameValue,
   $armResourceOperations,
   $armVirtualResource,
+  $customAzureResource,
   $extensionResource,
   $locationResource,
   $resourceBaseType,
@@ -51,6 +55,9 @@ export const $decorators = {
     armVirtualResource: $armVirtualResource,
     resourceBaseType: $resourceBaseType,
   } satisfies AzureResourceManagerDecorators,
+  "Azure.ResourceManager.Legacy": {
+    customAzureResource: $customAzureResource,
+  } satisfies AzureResourceManagerLegacyDecorators,
 };
 
 export const $flags = definePackageFlags({

packages/typespec-azure-resource-manager/test/resource.test.ts

@@ -716,6 +716,77 @@ describe("typespec-azure-resource-manager: ARM resource model", () => {
     strictEqual(nameProperty?.type.kind, "Scalar");
     strictEqual(nameProperty?.type.name, "WidgetNameType");
   });
+
+  it("emits diagnostics for non ARM resources", async () => {
+    const { diagnostics } = await checkFor(`
+      @armProviderNamespace
+      @useDependency(Azure.ResourceManager.Versions.v1_0_Preview_1)
+      namespace Microsoft.Contoso {
+       @parentResource(Microsoft.Person.Contoso.Person)
+        model Employee is TrackedResource<EmployeeProperties> {
+          ...ResourceNameParameter<Employee>;
+        }
+
+        /** Employee properties */
+        model EmployeeProperties {
+          /** The status of the last operation. */
+          @visibility("read")
+          provisioningState?: ProvisioningState;
+        }
+
+        /** The provisioning state of a resource. */
+        union ProvisioningState {
+          string,
+
+          /** Resource has been created. */
+          Succeeded: "Succeeded",
+
+          /** Resource creation failed. */
+          Failed: "Failed",
+
+          /** Resource creation was canceled. */
+          Canceled: "Canceled",
+        }
+
+        interface Operations extends Azure.ResourceManager.Operations {}
+
+        @armResourceOperations
+        interface Employees {
+          listByResourceGroup is ArmResourceListByParent<Employee>;
+        }
+      }
+
+      namespace Microsoft.Person.Contoso {
+        /** Person parent */
+        model Person {
+          /** The parent name */
+          @path
+          @visibility("read")
+          @segment("parents")
+          @key
+          name: string;
+        }
+      }
+`);
+    expectDiagnostics(diagnostics, [
+      {
+        code: "@azure-tools/typespec-azure-resource-manager/arm-resource-missing",
+        message: "No @armResource registration found for type Person",
+      },
+      {
+        code: "@azure-tools/typespec-azure-resource-manager/parent-type",
+        message: "Parent type Person of Employee is not registered as an ARM resource type.",
+      },
+      {
+        code: "@azure-tools/typespec-azure-resource-manager/arm-resource-missing",
+        message: "No @armResource registration found for type Person",
+      },
+      {
+        code: "@azure-tools/typespec-azure-resource-manager/parent-type",
+        message: "Parent type Person of Employee is not registered as an ARM resource type.",
+      },
+    ]);
+  });
 });
 
 it("emits default optional properties for resource", async () => {
@@ -761,3 +832,54 @@ it("emits required properties for resource with @armResourcePropertiesOptionalit
   strictEqual(resources.length, 1);
   strictEqual(resources[0].typespecType.properties.get("properties")?.optional, false);
 });
+
+it("recognizes resource with customResource identifier", async () => {
+  const { diagnostics } = await checkFor(`
+    @armProviderNamespace
+    @useDependency(Azure.ResourceManager.Versions.v1_0_Preview_1)
+    namespace Microsoft.Contoso {
+     @parentResource(Microsoft.Person.Contoso.Person)
+      model Employee is TrackedResource<EmployeeProperties> {
+        ...ResourceNameParameter<Employee>;
+      }
+
+      /** Employee properties */
+      model EmployeeProperties {
+        /** The status of the last operation. */
+        @visibility("read")
+        provisioningState?: ProvisioningState;
+      }
+
+      /** The provisioning state of a resource. */
+      union ProvisioningState {
+        string,
+
+        /** Resource has been created. */
+        Succeeded: "Succeeded",
+
+        /** Resource creation failed. */
+        Failed: "Failed",
+
+        /** Resource creation was canceled. */
+        Canceled: "Canceled",
+      }
+
+      interface Operations extends Azure.ResourceManager.Operations {}
+
+      @armResourceOperations
+      interface Employees {
+        listByResourceGroup is ArmResourceListByParent<Employee>;
+      }
+    }
+
+    namespace Microsoft.Person.Contoso {
+      /** Person parent */
+      @Azure.ResourceManager.Legacy.customAzureResource
+      model Person {
+        /** The parent name */
+        name: string;
+      }
+    }
+`);
+  expectDiagnosticEmpty(diagnostics);
+});