Add rule for RPC-Policy-V1-03: no properties of type object without a schema

.chronus/changes/almend-Rule-2024-8-17-16-58-23.md

@@ -0,0 +1,7 @@
+---
+changeKind: feature
+packages:
+  - "@azure-tools/typespec-azure-resource-manager"
+---
+
+Add `no-empty-model` rule

.chronus/changes/almend-Rule-2024-8-18-10-2-28.md

@@ -0,0 +1,7 @@
+---
+changeKind: feature
+packages:
+  - "@azure-tools/typespec-azure-rulesets"
+---
+
+Add `no-empty-model` rule to ruleset

docs/libraries/azure-resource-manager/reference/linter.md

@@ -56,3 +56,4 @@ Available ruleSets:
 | `@azure-tools/typespec-azure-resource-manager/resource-name`                                                                                                     | Check the resource name.                                                                                                                                                                                                                             |
 | `@azure-tools/typespec-azure-resource-manager/retry-after`                                                                                                       | Check if retry-after header appears in response body.                                                                                                                                                                                                |
 | [`@azure-tools/typespec-azure-resource-manager/unsupported-type`](/libraries/azure-resource-manager/rules/unsupported-type.md)                                   | Check for unsupported ARM types.                                                                                                                                                                                                                     |
+| [`@azure-tools/typespec-azure-resource-manager/no-empty-model`](/libraries/azure-resource-manager/rules/no-empty-model.md)                                       | ARM Properties with type:object that don't reference a model definition are not allowed. ARM doesn't allow generic type definitions as this leads to bad customer experience.                                                                        |

docs/libraries/azure-resource-manager/rules/no-empty-model.md

@@ -0,0 +1,51 @@
+---
+title: no-empty-model
+---
+
+```text title=- Full name-
+@azure-tools/typespec-azure-resource-manager/no-empty-model
+```
+
+ARM Properties with type:object that don't reference a model definition are not allowed. ARM doesn't allow generic type definitions as this leads to bad customer experience.
+
+#### ❌ Incorrect
+
+```tsp
+model Information {
+  address: {};
+}
+```
+
+#### ❌ Incorrect
+
+```tsp
+model Empty {}
+```
+
+#### ✅ Correct
+
+```tsp
+model Information {
+  address: Address;
+}
+
+model Address {
+  street: string;
+  city: string;
+  state: string;
+  country: string;
+  postalCode: string;
+}
+```
+
+#### ✅ Correct
+
+```tsp
+model Information {
+  street: string;
+  city: string;
+  state: string;
+  country: string;
+  postalCode: string;
+}
+```

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

@@ -60,6 +60,7 @@ Available ruleSets:
 | `@azure-tools/typespec-azure-resource-manager/resource-name`                                                                                                                                             | Check the resource name.                                                                                                                                                                                                                             |
 | `@azure-tools/typespec-azure-resource-manager/retry-after`                                                                                                                                               | Check if retry-after header appears in response body.                                                                                                                                                                                                |
 | [`@azure-tools/typespec-azure-resource-manager/unsupported-type`](https://azure.github.io/typespec-azure/docs/libraries/azure-resource-manager/rules/unsupported-type)                                   | Check for unsupported ARM types.                                                                                                                                                                                                                     |
+| [`@azure-tools/typespec-azure-resource-manager/no-empty-model`](https://azure.github.io/typespec-azure/docs/libraries/azure-resource-manager/rules/no-empty-model)                                       | ARM Properties with type:object that don't reference a model definition are not allowed. ARM doesn't allow generic type definitions as this leads to bad customer experience.                                                                        |
 
 ## Decorators
 

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

@@ -23,6 +23,7 @@ import { envelopePropertiesRules } from "./rules/envelope-properties.js";
 import { listBySubscriptionRule } from "./rules/list-operation.js";
 import { lroLocationHeaderRule } from "./rules/lro-location-header.js";
 import { missingXmsIdentifiersRule } from "./rules/missing-x-ms-identifiers.js";
+import { noEmptyModel } from "./rules/no-empty-model.js";
 import { noResponseBodyRule } from "./rules/no-response-body.js";
 import { operationsInterfaceMissingRule } from "./rules/operations-interface-missing.js";
 import { patchEnvelopePropertiesRules } from "./rules/patch-envelope-properties.js";
@@ -61,6 +62,7 @@ const rules = [
   resourceNameRule,
   retryAfterRule,
   unsupportedTypeRule,
+  noEmptyModel,
 ];
 
 export const $linter = defineLinter({

packages/typespec-azure-resource-manager/src/rules/no-empty-model.ts

@@ -0,0 +1,26 @@
+import { createRule, Model } from "@typespec/compiler";
+
+export const noEmptyModel = createRule({
+  name: "no-empty-model",
+  severity: "warning",
+  description:
+    "ARM Properties with type:object that don't reference a model definition are not allowed. ARM doesn't allow generic type definitions as this leads to bad customer experience.",
+  url: "https://azure.github.io/typespec-azure/docs/libraries/azure-resource-manager/rules/no-empty-model",
+  messages: {
+    default: "Properties with type:object must have definition of a reference model.",
+    extends:
+      "The `type:object` model is not defined in the payload. Define the reference model of the object or change the `type` to a primitive data type like string, int, etc",
+  },
+  create(context) {
+    return {
+      model: (model: Model) => {
+        if (model.properties.size === 0) {
+          context.reportDiagnostic({
+            code: "no-empty-model",
+            target: model,
+          });
+        }
+      },
+    };
+  },
+});

packages/typespec-azure-resource-manager/test/rules/no-empty-model.test.ts

@@ -0,0 +1,101 @@
+import {
+  BasicTestRunner,
+  LinterRuleTester,
+  createLinterRuleTester,
+} from "@typespec/compiler/testing";
+import { beforeEach, describe, it } from "vitest";
+import { noEmptyModel } from "../../src/rules/no-empty-model.js";
+import { createAzureResourceManagerTestRunner } from "../test-host.js";
+
+const armDef = `
+@armProviderNamespace
+@useDependency(Azure.ResourceManager.Versions.v1_0_Preview_1)
+namespace Microsoft.Contoso;
+`;
+
+describe("typespec-azure-resource-manager: arm properties type-object no definition rule", () => {
+  let runner: BasicTestRunner;
+  let tester: LinterRuleTester;
+
+  beforeEach(async () => {
+    runner = await createAzureResourceManagerTestRunner();
+    tester = createLinterRuleTester(
+      runner,
+      noEmptyModel,
+      "@azure-tools/typespec-azure-resource-manager",
+    );
+  });
+
+  it("emits diagnostic when a property use type:object that is not defined", async () => {
+    await tester
+      .expect(
+        ` 
+      ${armDef}
+      model Foo { 
+        props: {};
+      } 
+        `,
+      )
+      .toEmitDiagnostics({
+        code: "@azure-tools/typespec-azure-resource-manager/no-empty-model",
+        message: "Properties with type:object must have definition of a reference model.",
+      });
+  });
+
+  it("emits diagnostic when model type:object is not defined", async () => {
+    await tester
+      .expect(
+        ` 
+      ${armDef}
+      model Foo { } 
+        `,
+      )
+      .toEmitDiagnostics({
+        code: "@azure-tools/typespec-azure-resource-manager/no-empty-model",
+        message: "Properties with type:object must have definition of a reference model.",
+      });
+  });
+
+  it("valid when a property use type:object that is defined", async () => {
+    await tester
+      .expect(
+        `
+      ${armDef}
+      model WidgetProperties {
+        props: Foo;
+      }
+
+      model Foo{
+        Name: string;
+      }
+    `,
+      )
+      .toBeValid();
+  });
+
+  it("valid when a property use type:object known scalar", async () => {
+    await tester
+      .expect(
+        ` 
+      ${armDef}
+      model WidgetProperties {
+        Date: utcDateTime;
+      }
+        `,
+      )
+      .toBeValid();
+  });
+
+  it("valid when a property use a simple data type ", async () => {
+    await tester
+      .expect(
+        ` 
+      ${armDef}
+      model WidgetProperties {
+        Name: string;
+      }
+        `,
+      )
+      .toBeValid();
+  });
+});

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

@@ -50,6 +50,7 @@ export default {
 
     // Azure resource manager
     "@azure-tools/typespec-azure-resource-manager/arm-no-record": true,
+    "@azure-tools/typespec-azure-resource-manager/no-empty-model": true,
     "@azure-tools/typespec-azure-resource-manager/arm-common-types-version": true,
     "@azure-tools/typespec-azure-resource-manager/arm-delete-operation-response-codes": true,
     "@azure-tools/typespec-azure-resource-manager/arm-put-operation-response-codes": true,