lint: enable no extraneous class

.oxlintrc.json

@@ -19,7 +19,7 @@
     "oxc/no-map-spread": "off",
     "typescript/consistent-return": "error",
     "typescript/no-explicit-any": "error",
-    "typescript/no-extraneous-class": "off",
+    "typescript/no-extraneous-class": "error",
     "typescript/no-unnecessary-type-conversion": "error",
     "typescript/no-unsafe-type-assertion": "off",
     "unicorn/consistent-function-scoping": "off",

extensions/acpx/src/service.test.ts

@@ -19,7 +19,7 @@ vi.mock("../runtime-api.js", () => ({
 
 vi.mock("./runtime.js", () => ({
   ACPX_BACKEND_ID: "acpx",
-  AcpxRuntime: class {},
+  AcpxRuntime: function AcpxRuntime() {},
   createAgentRegistry: vi.fn(() => ({})),
   createFileSessionStore: vi.fn(() => ({})),
 }));

extensions/diagnostics-otel/src/service.test.ts

@@ -52,23 +52,21 @@ vi.mock("@opentelemetry/sdk-node", () => ({
 }));
 
 vi.mock("@opentelemetry/exporter-metrics-otlp-proto", () => ({
-  OTLPMetricExporter: class {},
+  OTLPMetricExporter: function OTLPMetricExporter() {},
 }));
 
 vi.mock("@opentelemetry/exporter-trace-otlp-proto", () => ({
-  OTLPTraceExporter: class {
-    constructor(options?: unknown) {
-      traceExporterCtor(options);
-    }
+  OTLPTraceExporter: function OTLPTraceExporter(options?: unknown) {
+    traceExporterCtor(options);
   },
 }));
 
 vi.mock("@opentelemetry/exporter-logs-otlp-proto", () => ({
-  OTLPLogExporter: class {},
+  OTLPLogExporter: function OTLPLogExporter() {},
 }));
 
 vi.mock("@opentelemetry/sdk-logs", () => ({
-  BatchLogRecordProcessor: class {},
+  BatchLogRecordProcessor: function BatchLogRecordProcessor() {},
   LoggerProvider: class {
     getLogger = vi.fn(() => ({
       emit: logEmit,
@@ -78,19 +76,18 @@ vi.mock("@opentelemetry/sdk-logs", () => ({
 }));
 
 vi.mock("@opentelemetry/sdk-metrics", () => ({
-  PeriodicExportingMetricReader: class {},
+  PeriodicExportingMetricReader: function PeriodicExportingMetricReader() {},
 }));
 
 vi.mock("@opentelemetry/sdk-trace-base", () => ({
-  ParentBasedSampler: class {},
-  TraceIdRatioBasedSampler: class {},
+  ParentBasedSampler: function ParentBasedSampler() {},
+  TraceIdRatioBasedSampler: function TraceIdRatioBasedSampler() {},
 }));
 
 vi.mock("@opentelemetry/resources", () => ({
   resourceFromAttributes: vi.fn((attrs: Record<string, unknown>) => attrs),
-  Resource: class {
-    // eslint-disable-next-line @typescript-eslint/no-useless-constructor
-    constructor(_value?: unknown) {}
+  Resource: function Resource(_value?: unknown) {
+    // Constructor shape required by the mocked OpenTelemetry API.
   },
 }));
 

extensions/discord/src/components.ts

@@ -65,7 +65,7 @@ export type {
 } from "./components.types.js";
 // Some test-only module graphs partially mock `@buape/carbon` and can drop `Modal`.
 // Keep dynamic form definitions loadable instead of crashing unrelated suites.
-const ModalBase: typeof Modal = Modal ?? class {};
+const ModalBase: typeof Modal = Modal ?? (function ModalFallback() {} as unknown as typeof Modal);
 
 export const DISCORD_COMPONENT_ATTACHMENT_PREFIX = "attachment://";
 

extensions/discord/src/monitor.test.ts

@@ -72,7 +72,9 @@ beforeEach(() => {
 });
 
 describe("registerDiscordListener", () => {
-  class FakeListener {}
+  class FakeListener {
+    readonly testListener = true;
+  }
 
   it("dedupes listeners by constructor", () => {
     const listeners: object[] = [];

extensions/discord/src/monitor/provider.proxy.test.ts

@@ -92,22 +92,17 @@ vi.mock("https-proxy-agent", () => ({
 }));
 
 vi.mock("undici", () => ({
-  ProxyAgent: class {
-    proxyUrl: string;
-    constructor(proxyUrl: string) {
-      this.proxyUrl = proxyUrl;
-      undiciProxyAgentSpy(proxyUrl);
-      restProxyAgentSpy(proxyUrl);
-    }
+  ProxyAgent: function ProxyAgent(this: { proxyUrl: string }, proxyUrl: string) {
+    this.proxyUrl = proxyUrl;
+    undiciProxyAgentSpy(proxyUrl);
+    restProxyAgentSpy(proxyUrl);
   },
   fetch: undiciFetchMock,
 }));
 
 vi.mock("ws", () => ({
-  default: class MockWebSocket {
-    constructor(url: string, options?: { agent?: unknown }) {
-      webSocketSpy(url, options);
-    }
+  default: function MockWebSocket(url: string, options?: { agent?: unknown }) {
+    webSocketSpy(url, options);
   },
 }));
 
@@ -132,19 +127,14 @@ describe("createDiscordGatewayPlugin", () => {
     return {
       HttpsProxyAgentCtor:
         HttpsProxyAgent as unknown as typeof import("https-proxy-agent").HttpsProxyAgent,
-      ProxyAgentCtor: class {
-        proxyUrl: string;
-        constructor(proxyUrl: string) {
-          this.proxyUrl = proxyUrl;
-          undiciProxyAgentSpy(proxyUrl);
-          restProxyAgentSpy(proxyUrl);
-        }
+      ProxyAgentCtor: function ProxyAgentCtor(this: { proxyUrl: string }, proxyUrl: string) {
+        this.proxyUrl = proxyUrl;
+        undiciProxyAgentSpy(proxyUrl);
+        restProxyAgentSpy(proxyUrl);
       } as unknown as typeof import("undici").ProxyAgent,
       undiciFetch: undiciFetchMock,
-      webSocketCtor: class {
-        constructor(url: string, options?: { agent?: unknown }) {
-          webSocketSpy(url, options);
-        }
+      webSocketCtor: function WebSocketCtor(url: string, options?: { agent?: unknown }) {
+        webSocketSpy(url, options);
       } as unknown as new (url: string, options?: { agent?: unknown }) => import("ws").WebSocket,
       registerClient: async (_plugin: unknown, client: unknown) => {
         baseRegisterClientSpy(client);

extensions/discord/src/monitor/provider.startup.test.ts

@@ -58,11 +58,11 @@ vi.mock("./gateway-supervisor.js", () => ({
 }));
 
 vi.mock("./listeners.js", () => ({
-  DiscordMessageListener: class DiscordMessageListener {},
-  DiscordPresenceListener: class DiscordPresenceListener {},
-  DiscordReactionListener: class DiscordReactionListener {},
-  DiscordReactionRemoveListener: class DiscordReactionRemoveListener {},
-  DiscordThreadUpdateListener: class DiscordThreadUpdateListener {},
+  DiscordMessageListener: function DiscordMessageListener() {},
+  DiscordPresenceListener: function DiscordPresenceListener() {},
+  DiscordReactionListener: function DiscordReactionListener() {},
+  DiscordReactionRemoveListener: function DiscordReactionRemoveListener() {},
+  DiscordThreadUpdateListener: function DiscordThreadUpdateListener() {},
   registerDiscordListener: vi.fn(),
 }));
 

extensions/discord/src/monitor/provider.test.ts

@@ -77,8 +77,8 @@ function createConfigWithDiscordAccount(overrides: Record<string, unknown> = {})
 vi.mock("../voice/manager.runtime.js", () => {
   voiceRuntimeModuleLoadedMock();
   return {
-    DiscordVoiceManager: class DiscordVoiceManager {},
-    DiscordVoiceReadyListener: class DiscordVoiceReadyListener {},
+    DiscordVoiceManager: function DiscordVoiceManager() {},
+    DiscordVoiceReadyListener: function DiscordVoiceReadyListener() {},
   };
 });
 describe("monitorDiscordProvider", () => {
@@ -173,8 +173,8 @@ describe("monitorDiscordProvider", () => {
     providerTesting.setLoadDiscordVoiceRuntime(async () => {
       voiceRuntimeModuleLoadedMock();
       return {
-        DiscordVoiceManager: class DiscordVoiceManager {},
-        DiscordVoiceReadyListener: class DiscordVoiceReadyListener {},
+        DiscordVoiceManager: function DiscordVoiceManager() {},
+        DiscordVoiceReadyListener: function DiscordVoiceReadyListener() {},
       } as never;
     });
     providerTesting.setLoadDiscordProviderSessionRuntime(

extensions/discord/src/test-support/provider.test-support.ts

@@ -341,7 +341,7 @@ vi.mock("@buape/carbon/gateway", () => ({
 }));
 
 vi.mock("@buape/carbon/voice", () => ({
-  VoicePlugin: class VoicePlugin {},
+  VoicePlugin: function VoicePlugin() {},
 }));
 
 vi.mock("openclaw/plugin-sdk/acp-runtime", async () => {
@@ -472,11 +472,11 @@ vi.mock(buildDiscordSourceModuleId("monitor/gateway-plugin.js"), () => ({
 }));
 
 vi.mock(buildDiscordSourceModuleId("monitor/listeners.js"), () => ({
-  DiscordMessageListener: class DiscordMessageListener {},
-  DiscordPresenceListener: class DiscordPresenceListener {},
-  DiscordReactionListener: class DiscordReactionListener {},
-  DiscordReactionRemoveListener: class DiscordReactionRemoveListener {},
-  DiscordThreadUpdateListener: class DiscordThreadUpdateListener {},
+  DiscordMessageListener: function DiscordMessageListener() {},
+  DiscordPresenceListener: function DiscordPresenceListener() {},
+  DiscordReactionListener: function DiscordReactionListener() {},
+  DiscordReactionRemoveListener: function DiscordReactionRemoveListener() {},
+  DiscordThreadUpdateListener: function DiscordThreadUpdateListener() {},
   registerDiscordListener: vi.fn(),
 }));
 

extensions/googlechat/src/targets.test.ts

@@ -27,7 +27,7 @@ vi.mock("../runtime-api.js", async () => {
 });
 
 vi.mock("google-auth-library", () => ({
-  GoogleAuth: class {},
+  GoogleAuth: function GoogleAuth() {},
   OAuth2Client: class {
     verifyIdToken = mocks.verifyIdToken;
   },

extensions/matrix/src/matrix/sdk/transport.test.ts

@@ -136,9 +136,9 @@ describe("performMatrixRequest", () => {
       });
     });
     (globalThis as Record<string, unknown>)[TEST_UNDICI_RUNTIME_DEPS_KEY] = {
-      Agent: class MockAgent {},
-      EnvHttpProxyAgent: class MockEnvHttpProxyAgent {},
-      ProxyAgent: class MockProxyAgent {},
+      Agent: function MockAgent() {},
+      EnvHttpProxyAgent: function MockEnvHttpProxyAgent() {},
+      ProxyAgent: function MockProxyAgent() {},
       fetch: runtimeFetch,
     };
 

extensions/matrix/src/test-mocks.ts

@@ -36,7 +36,7 @@ export function createMatrixBotSdkMock(params: MatrixBotSdkMockParams = {}): Mat
       warn = vi.fn();
       error = vi.fn();
     },
-    MatrixClient: params.matrixClient ?? class {},
+    MatrixClient: params.matrixClient ?? function MatrixClient() {},
     LogService: {
       setLogger: vi.fn(),
       ...(params.includeVerboseLogService
@@ -47,7 +47,9 @@ export function createMatrixBotSdkMock(params: MatrixBotSdkMockParams = {}): Mat
           }
         : {}),
     },
-    SimpleFsStorageProvider: params.simpleFsStorageProvider ?? class {},
-    RustSdkCryptoStorageProvider: params.rustSdkCryptoStorageProvider ?? class {},
+    SimpleFsStorageProvider:
+      params.simpleFsStorageProvider ?? function SimpleFsStorageProvider() {},
+    RustSdkCryptoStorageProvider:
+      params.rustSdkCryptoStorageProvider ?? function RustSdkCryptoStorageProvider() {},
   };
 }

extensions/msteams/src/monitor.lifecycle.test.ts

@@ -104,8 +104,8 @@ const jwtValidate = vi.hoisted(() => vi.fn().mockResolvedValue(true));
 const loadMSTeamsSdkWithAuth = vi.hoisted(() =>
   vi.fn(async () => ({
     sdk: {
-      ActivityHandler: class {},
-      MsalTokenProvider: class {},
+      ActivityHandler: function ActivityHandler() {},
+      MsalTokenProvider: function MsalTokenProvider() {},
       authorizeJWT:
         () => (_req: unknown, _res: unknown, next: ((err?: unknown) => void) | undefined) =>
           next?.(),

extensions/msteams/src/probe.test.ts

@@ -23,7 +23,7 @@ vi.mock("@microsoft/teams.apps", () => ({
 }));
 
 vi.mock("@microsoft/teams.api", () => ({
-  Client: class {},
+  Client: function Client() {},
 }));
 
 import { probeMSTeams } from "./probe.js";

extensions/slack/src/monitor/provider.interop.test.ts

@@ -2,8 +2,8 @@ import { describe, expect, it } from "vitest";
 import { __testing } from "./provider.js";
 
 describe("resolveSlackBoltInterop", () => {
-  class FakeApp {}
-  class FakeHTTPReceiver {}
+  function FakeApp() {}
+  function FakeHTTPReceiver() {}
 
   it("uses the default import when it already exposes named exports", () => {
     const resolved = __testing.resolveSlackBoltInterop({

extensions/telegram/src/send.proxy.test.ts

@@ -59,7 +59,7 @@ vi.mock("grammy", () => ({
   GrammyError: class GrammyError extends Error {
     description = "";
   },
-  InputFile: class {},
+  InputFile: function InputFile() {},
 }));
 
 let deleteMessageTelegram: typeof import("./send.js").deleteMessageTelegram;

extensions/telegram/src/send.test-harness.ts

@@ -124,7 +124,7 @@ vi.mock("grammy", () => ({
   GrammyError: class GrammyError extends Error {
     description = "";
   },
-  InputFile: class {},
+  InputFile: function InputFile() {},
 }));
 
 vi.mock("undici", () => ({

extensions/twitch/src/probe.test.ts

@@ -47,7 +47,7 @@ vi.mock("@twurple/chat", () => ({
 }));
 
 vi.mock("@twurple/auth", () => ({
-  StaticAuthProvider: class {},
+  StaticAuthProvider: function StaticAuthProvider() {},
 }));
 
 describe("probeTwitch", () => {

extensions/twitch/src/twitch-client.test.ts

@@ -58,10 +58,8 @@ const mockAuthProvider = {
 };
 
 vi.mock("@twurple/auth", () => ({
-  StaticAuthProvider: class {
-    constructor(...args: unknown[]) {
-      mockAuthProvider.constructor(...args);
-    }
+  StaticAuthProvider: function StaticAuthProvider(...args: unknown[]) {
+    mockAuthProvider.constructor(...args);
   },
   RefreshingAuthProvider: class {
     addUserForToken = mockAddUserForToken;

src/acp/server.startup.test.ts

@@ -56,11 +56,12 @@ class MockGatewayClient {
 }
 
 vi.mock("@agentclientprotocol/sdk", () => ({
-  AgentSideConnection: class {
-    constructor(factory: (conn: unknown) => unknown, stream: unknown) {
-      mockState.agentSideConnectionCtor(factory, stream);
-      factory({});
-    }
+  AgentSideConnection: function AgentSideConnection(
+    factory: (conn: unknown) => unknown,
+    stream: unknown,
+  ) {
+    mockState.agentSideConnectionCtor(factory, stream);
+    factory({});
   },
   ndJsonStream: vi.fn(() => ({ type: "mock-stream" })),
 }));

src/agents/model-catalog.test-harness.ts

@@ -39,7 +39,7 @@ export function mockCatalogImportFailThenRecover() {
     }
     return {
       discoverAuthStorage: () => ({}),
-      AuthStorage: class {},
+      AuthStorage: function AuthStorage() {},
       ModelRegistry: class {
         getAll() {
           return [{ id: "gpt-4.1", name: "GPT-4.1", provider: "openai" }];

src/agents/model-catalog.test.ts

@@ -25,7 +25,7 @@ function mockCatalogImportFailThenRecover() {
     }
     return {
       discoverAuthStorage: () => ({}),
-      AuthStorage: class {},
+      AuthStorage: function AuthStorage() {},
       ModelRegistry: class {
         getAll() {
           return [{ id: "gpt-4.1", name: "GPT-4.1", provider: "openai" }];
@@ -41,7 +41,7 @@ function mockPiDiscoveryModels(models: unknown[]) {
     async () =>
       ({
         discoverAuthStorage: () => ({}),
-        AuthStorage: class {},
+        AuthStorage: function AuthStorage() {},
         ModelRegistry: class {
           getAll() {
             return models;
@@ -118,7 +118,7 @@ describe("loadModelCatalog", () => {
         async () =>
           ({
             discoverAuthStorage: () => ({}),
-            AuthStorage: class {},
+            AuthStorage: function AuthStorage() {},
             ModelRegistry: class {
               getAll() {
                 return [

src/agents/pi-embedded-runner/compact.hooks.harness.ts

@@ -230,8 +230,8 @@ export async function loadCompactHooksHarness(): Promise<{
   });
 
   vi.doMock("@mariozechner/pi-coding-agent", () => ({
-    AuthStorage: class AuthStorage {},
-    ModelRegistry: class ModelRegistry {},
+    AuthStorage: function AuthStorage() {},
+    ModelRegistry: function ModelRegistry() {},
     createAgentSession: vi.fn(async () => {
       const session = {
         sessionId: "session-1",
@@ -261,7 +261,7 @@ export async function loadCompactHooksHarness(): Promise<{
       };
       return { session };
     }),
-    DefaultResourceLoader: class DefaultResourceLoader {},
+    DefaultResourceLoader: function DefaultResourceLoader() {},
     SessionManager: {
       open: vi.fn(() => ({})),
     },

src/agents/pi-embedded-runner/run/attempt.spawn-workspace.test-support.ts

@@ -161,11 +161,11 @@ vi.mock("@mariozechner/pi-coding-agent", async () => {
   const actual = await vi.importActual<typeof import("@mariozechner/pi-coding-agent")>(
     "@mariozechner/pi-coding-agent",
   );
-  class AuthStorage {}
+  function AuthStorage() {}
   class DefaultResourceLoader {
     async reload() {}
   }
-  class ModelRegistry {}
+  function ModelRegistry() {}
 
   return {
     ...actual,

src/agents/pi-model-discovery.compat.e2e.test.ts

@@ -8,8 +8,8 @@ describe("pi-model-discovery module compatibility", () => {
   it("loads when InMemoryAuthStorageBackend is not exported", async () => {
     vi.resetModules();
     vi.doMock("@mariozechner/pi-coding-agent", () => {
-      class MockAuthStorage {}
-      class MockModelRegistry {}
+      function MockAuthStorage() {}
+      function MockModelRegistry() {}
 
       return {
         AuthStorage: MockAuthStorage,

src/agents/subagent-registry-run-manager.ts

@@ -277,8 +277,7 @@ export function createSubagentRunManager(params: {
     const runId = registerParams.runId.trim();
     const childSessionKey = registerParams.childSessionKey.trim();
     const requesterSessionKey = registerParams.requesterSessionKey.trim();
-    const controllerSessionKey =
-      registerParams.controllerSessionKey?.trim() || requesterSessionKey;
+    const controllerSessionKey = registerParams.controllerSessionKey?.trim() || requesterSessionKey;
     if (!runId || !childSessionKey || !requesterSessionKey) {
       return;
     }

src/infra/plain-object.test.ts

@@ -6,7 +6,9 @@ describe("isPlainObject", () => {
     {},
     { a: 1 },
     Object.create(null),
-    new (class X {})(),
+    new (class X {
+      readonly marker = true;
+    })(),
     { [Symbol.toStringTag]: "Object" },
   ])("accepts object-tag values: %j", (value) => {
     expect(isPlainObject(value)).toBe(true);

ui/src/ui/app-gateway.sessions.node.test.ts

@@ -44,7 +44,7 @@ vi.mock("./controllers/sessions.ts", () => ({
   subscribeSessions: vi.fn(),
 }));
 vi.mock("./gateway.ts", () => ({
-  GatewayBrowserClient: class {},
+  GatewayBrowserClient: function GatewayBrowserClient() {},
   resolveGatewayErrorDetailCode: () => null,
 }));