[TCGC] generate names for anonymous models in LRO

.chronus/changes/tcgc_fix_lro_anonymous_models-2025-11-3-17-24-7.md

@@ -0,0 +1,7 @@
+---
+changeKind: fix
+packages:
+  - "@azure-tools/typespec-client-generator-core"
+---
+
+Generate names for anonymous models in LroMetadata.

packages/typespec-client-generator-core/src/public-utils.ts

@@ -1,3 +1,4 @@
+import { getLroMetadata } from "@azure-tools/typespec-azure-core";
 import {
   Diagnostic,
   Enum,
@@ -503,6 +504,27 @@ function getContextPath(
       }
     }
 
+    const lroMetadata = getLroMetadata(context.program, root);
+    if (lroMetadata) {
+      const anonymousCandidates = [
+        { lroResultType: lroMetadata.finalResult, label: "FinalResult" },
+        { lroResultType: lroMetadata.logicalResult, label: "LogicalResult" },
+        { lroResultType: lroMetadata.envelopeResult, label: "EnvelopeResult" },
+        { lroResultType: lroMetadata.finalEnvelopeResult, label: "FinalEnvelopeResult" },
+      ];
+
+      for (const { lroResultType, label } of anonymousCandidates) {
+        if (!lroResultType || lroResultType === "void") {
+          continue;
+        }
+        visited.clear();
+        result = [{ name: root.name, type: root }];
+        if (dfsModelProperties(typeToFind, lroResultType, label)) {
+          return result;
+        }
+      }
+    }
+
     const overriddenClientMethod = getOverriddenClientMethod(context, root);
     visited.clear();
     result = [{ name: root.name, type: root }];

packages/typespec-client-generator-core/test/methods/lro.test.ts

@@ -816,6 +816,81 @@ describe("data plane LRO templates", () => {
     );
     strictEqual(lroMetadata.pollingStep.responseBody, analyzeOperationModel);
   });
+
+  // https://github.com/Azure/typespec-azure/issues/2325
+  it("LroMetadata synthetic anonymous ResourceOperationStatus", async () => {
+    await runner.compileWithVersionedService(`
+      alias ServiceTraits = NoRepeatableRequests &
+        NoConditionalRequests &
+        NoClientRequestId;
+
+      alias apiOperations = Azure.Core.ResourceOperations<ServiceTraits>;
+
+      @doc("Create an instruction.")
+      @pollingOperation(
+        OperationProgress.getOperationResult
+      )
+      op update is apiOperations.LongRunningResourceCreateOrUpdate<Instruction>;
+
+      @resource("instruction")
+      model Instruction {
+        @key
+        @visibility(Lifecycle.Read)
+        id: string;
+
+        @visibility(Lifecycle.Update)
+        instructionId: string;
+      }
+
+      @doc("Operation Response Model")
+      @resource("operation")
+      model OperationResultQuery {
+        @doc("The operation status.")
+        @visibility(Lifecycle.Read)
+        status: Foundations.OperationState;
+
+        @doc("The operation id.")
+        @key("operationId")
+        @visibility(Lifecycle.Read)
+        operationId: string;
+
+        @doc("The error message.")
+        @visibility(Lifecycle.Read)
+        errorMessage: string[];
+      }
+
+      model UpdateFinalResult {
+        id2: string;
+      }
+
+      @doc("Get operation progress")
+      interface OperationProgress {
+        @doc("Get operation progress")
+        getOperationResult is apiOperations.ResourceRead<OperationResultQuery>;
+      }
+    `);
+    const method = runner.context.sdkPackage.clients[0].methods.find((m) => m.name === "update");
+    assert.exists(method);
+    strictEqual(method.kind, "lro");
+    const response = method.response.type;
+    assert.strictEqual(response?.kind, "model");
+    if (!response || response.kind !== "model") {
+      assert.fail("Expected final response to be a model.");
+    }
+    assert.isTrue(response.isGeneratedName);
+    const generatedName = response.name;
+    // duplicate with existing model named "UpdateFinalResult" so the generated name will be "UpdateFinalResult1"
+    assert.strictEqual("UpdateFinalResult1", generatedName);
+    const crossLanguageId = response.crossLanguageDefinitionId;
+    assert.isFalse(crossLanguageId.includes(".."));
+    const lroMetadata = method.lroMetadata;
+    assert.exists(lroMetadata);
+    const finalResponse = lroMetadata.finalResponse;
+    assert.exists(finalResponse);
+    const finalResult = finalResponse.result;
+    assert.exists(finalResult);
+    assert.strictEqual(finalResult.name, "UpdateFinalResult1");
+  });
 });
 
 describe("Arm LRO templates", () => {

packages/typespec-client-generator-core/test/rules/no-unnamed-types.test.ts

@@ -1,8 +1,11 @@
+import { AzureCoreTestLibrary } from "@azure-tools/typespec-azure-core/testing";
+import { AzureResourceManagerTestLibrary } from "@azure-tools/typespec-azure-resource-manager/testing";
 import {
   BasicTestRunner,
   createLinterRuleTester,
   LinterRuleTester,
 } from "@typespec/compiler/testing";
+import { OpenAPITestLibrary } from "@typespec/openapi/testing";
 import { beforeEach, describe, it } from "vitest";
 import { noUnnamedTypesRule } from "../../src/rules/no-unnamed-types.rule.js";
 import { createSdkTestRunner } from "../test-host.js";
@@ -11,7 +14,10 @@ let runner: BasicTestRunner;
 let tester: LinterRuleTester;
 
 beforeEach(async () => {
-  runner = await createSdkTestRunner();
+  runner = await createSdkTestRunner({
+    librariesToAdd: [AzureCoreTestLibrary, OpenAPITestLibrary],
+    autoImports: ["@azure-tools/typespec-azure-core"],
+  });
   tester = createLinterRuleTester(
     runner,
     noUnnamedTypesRule,
@@ -233,6 +239,49 @@ describe("models", () => {
       )
       .toBeValid();
   });
+
+  it("anonymous model caused by lro metadata", async () => {
+    const armRunner = await createSdkTestRunner({
+      librariesToAdd: [AzureResourceManagerTestLibrary, AzureCoreTestLibrary, OpenAPITestLibrary],
+      autoImports: ["@azure-tools/typespec-azure-resource-manager"],
+      autoUsings: ["Azure.ResourceManager", "Azure.Core", "Azure.Core.Traits"],
+    });
+    const armTester = createLinterRuleTester(
+      armRunner,
+      noUnnamedTypesRule,
+      "@azure-tools/typespec-client-generator-core",
+    );
+    await armTester
+      .expect(
+        `
+        @armProviderNamespace
+        @service
+        @versioned(Versions)
+        namespace TestClient;
+        enum Versions {
+          @armCommonTypesVersion(Azure.ResourceManager.CommonTypes.Versions.v5)
+          v1: "v1",
+        }
+        model Employee is TrackedResource<EmployeeProperties> {
+          ...ResourceNameParameter<Employee>;
+        }
+        model MoveRequest {
+          targetResourceGroup?: string;
+        }
+        model EmployeeProperties {
+          age?: int32;
+        }
+        op move is ArmResourceActionAsync<Employee, MoveRequest, {@body body: {id?: string}}>;
+        `,
+      )
+      .toEmitDiagnostics([
+        {
+          code: "@azure-tools/typespec-client-generator-core/no-unnamed-types",
+          severity: "warning",
+          message: `Anonymous model with generated name "MoveFinalResult" detected. Define this model separately with a proper name to improve code readability and reusability.`,
+        },
+      ]);
+  });
 });
 
 describe("unions", () => {