[chat] Add chat/test entrypoint for consumer test utilities

packages/chat/package.json

@@ -18,6 +18,10 @@
     "./jsx-dev-runtime": {
       "types": "./dist/jsx-runtime.d.ts",
       "import": "./dist/jsx-runtime.js"
+    },
+    "./test": {
+      "types": "./dist/test.d.ts",
+      "import": "./dist/test.js"
     }
   },
   "files": [
@@ -41,6 +45,14 @@
     "remend": "^1.2.1",
     "unified": "^11.0.5"
   },
+  "peerDependencies": {
+    "vitest": ">=2.0.0"
+  },
+  "peerDependenciesMeta": {
+    "vitest": {
+      "optional": true
+    }
+  },
   "devDependencies": {
     "@types/mdast": "^4.0.4",
     "@types/node": "^25.3.2",

packages/chat/src/mock-adapter.ts

@@ -4,13 +4,16 @@
 import { vi } from "vitest";
 import { parseMarkdown } from "./markdown";
 import { Message, type MessageData } from "./message";
+import { ThreadImpl } from "./thread";
 import type {
   Adapter,
+  ChannelVisibility,
   FormattedContent,
   Lock,
   Logger,
   QueueEntry,
   StateAdapter,
+  Thread,
 } from "./types";
 
 /**
@@ -220,7 +223,7 @@ export function createMockState(): MockStateAdapter {
 }
 
 /**
- * Create a test message for testing.
+ * Create a test message.
  * @param id - Message ID
  * @param text - Message text content
  * @param overrides - Optional overrides for message fields
@@ -252,3 +255,62 @@ export function createTestMessage(
     ...overrides,
   });
 }
+
+let threadCounter = 0;
+
+/** Options for creating a test thread. All fields optional — sensible defaults provided. */
+export interface CreateTestThreadOptions {
+  /** Adapter name (default: "slack") */
+  adapter?: string;
+  /** Partial overrides merged onto the mock adapter's spy methods */
+  adapterOverrides?: Partial<Adapter>;
+  id?: string;
+  channelId?: string;
+  channelVisibility?: ChannelVisibility;
+  currentMessage?: Message;
+  fallbackStreamingPlaceholderText?: string | null;
+  initialMessage?: Message;
+  isDM?: boolean;
+  isSubscribedContext?: boolean;
+  logger?: Logger;
+  streamingUpdateIntervalMs?: number;
+}
+
+/** Return value of createTestThread. */
+export interface TestThread {
+  thread: Thread;
+  mockAdapter: Adapter;
+  mockState: MockStateAdapter;
+}
+
+/**
+ * Create a test thread backed by a mock adapter with spyable methods.
+ * All adapter methods (post, edit, fetchMessages, etc.) are vi.fn() spies.
+ */
+export function createTestThread(opts?: CreateTestThreadOptions): TestThread {
+  const {
+    adapter: adapterName = "slack",
+    adapterOverrides,
+    id: idOpt,
+    channelId: channelIdOpt,
+    ...rest
+  } = opts ?? {};
+  const mockAdapter = {
+    ...createMockAdapter(adapterName),
+    ...adapterOverrides,
+  };
+  const mockState = createMockState();
+  const counter = ++threadCounter;
+  const id = idOpt ?? `${adapterName}:C${counter}:thread`;
+  const channelId = channelIdOpt ?? `C${counter}`;
+
+  const thread = new ThreadImpl({
+    id,
+    channelId,
+    adapter: mockAdapter,
+    stateAdapter: mockState,
+    ...rest,
+  });
+
+  return { thread, mockAdapter, mockState };
+}

packages/chat/src/test.ts

@@ -0,0 +1,42 @@
+import type { MessageData } from "./message";
+import { createTestMessage as _createTestMessage } from "./mock-adapter";
+import type { Author } from "./types";
+
+export {
+  createTestThread,
+  type CreateTestThreadOptions,
+  type MockStateAdapter,
+  type TestThread,
+} from "./mock-adapter";
+
+let messageCounter = 0;
+
+/** Create a test message with sensible defaults. Only `text` is required. Extra properties are spread as MessageData overrides. */
+export function createTestMessage(
+  opts: {
+    text: string;
+    id?: string;
+    author?: Partial<Author>;
+    raw?: unknown;
+    edited?: boolean;
+  } & Omit<
+    Partial<MessageData>,
+    "text" | "id" | "author" | "raw" | "formatted"
+  >
+) {
+  const { text, id, author, raw, edited, ...rest } = opts;
+  const overrides: Partial<MessageData> = { raw: raw ?? {}, ...rest };
+  if (edited != null) {
+    overrides.metadata = { dateSent: new Date(), edited };
+  }
+  if (author) {
+    overrides.author = {
+      userId: author.userId ?? "U000",
+      userName: author.userName ?? "testuser",
+      fullName: author.fullName ?? "Test User",
+      isBot: author.isBot ?? false,
+      isMe: author.isMe ?? false,
+    };
+  }
+  return _createTestMessage(id ?? `msg-${++messageCounter}`, text, overrides);
+}

packages/chat/tsup.config.ts

@@ -1,9 +1,10 @@
 import { defineConfig } from "tsup";
 
 export default defineConfig({
-  entry: ["src/index.ts", "src/jsx-runtime.ts"],
+  entry: ["src/index.ts", "src/jsx-runtime.ts", "src/test.ts"],
   format: ["esm"],
   dts: true,
   clean: true,
   sourcemap: false,
+  external: ["vitest"],
 });