base class and unit tests

libs/langchain-standard-tests/package.json

@@ -32,7 +32,8 @@
   "author": "LangChain",
   "license": "MIT",
   "dependencies": {
-    "@langchain/core": "workspace:*"
+    "@langchain/core": "workspace:*",
+    "zod": "^3.22.4"
   },
   "devDependencies": {
     "@jest/globals": "^29.5.0",

libs/langchain-standard-tests/src/base.ts

@@ -0,0 +1,31 @@
+import {
+  BaseChatModel,
+  BaseChatModelCallOptions,
+} from "@langchain/core/language_models/chat_models";
+import { BaseMessageChunk } from "@langchain/core/messages";
+
+export type BaseChatModelConstructor<
+  CallOptions extends BaseChatModelCallOptions = BaseChatModelCallOptions,
+  OutputMessageType extends BaseMessageChunk = BaseMessageChunk
+> = new (...args: any[]) => BaseChatModel<CallOptions, OutputMessageType>;
+
+export type BaseChatModelsTestsFields<
+  CallOptions extends BaseChatModelCallOptions = BaseChatModelCallOptions,
+  OutputMessageType extends BaseMessageChunk = BaseMessageChunk
+> = {
+  cls: BaseChatModelConstructor<CallOptions, OutputMessageType>;
+};
+
+export class BaseChatModelsTests<
+  CallOptions extends BaseChatModelCallOptions = BaseChatModelCallOptions,
+  OutputMessageType extends BaseMessageChunk = BaseMessageChunk
+> implements BaseChatModelsTestsFields<CallOptions, OutputMessageType>
+{
+  cls: BaseChatModelConstructor<CallOptions, OutputMessageType>;
+
+  constructor(
+    fields: BaseChatModelsTestsFields<CallOptions, OutputMessageType>
+  ) {
+    this.cls = fields.cls;
+  }
+}

libs/langchain-standard-tests/src/integration_tests/chat_models.ts

@@ -1 +1,21 @@
-export {};
+import {
+  BaseChatModel,
+  BaseChatModelCallOptions,
+} from "@langchain/core/language_models/chat_models";
+import { BaseMessageChunk } from "@langchain/core/messages";
+
+type BaseChatModelConstructor<
+  CallOptions extends BaseChatModelCallOptions = BaseChatModelCallOptions,
+  OutputMessageType extends BaseMessageChunk = BaseMessageChunk
+> = new (...args: any[]) => BaseChatModel<CallOptions, OutputMessageType>;
+
+export class ChatModelsIntegrationTests<
+  CallOptions extends BaseChatModelCallOptions = BaseChatModelCallOptions,
+  OutputMessageType extends BaseMessageChunk = BaseMessageChunk
+> {
+  cls: BaseChatModel<CallOptions, OutputMessageType>;
+
+  constructor(cls: BaseChatModelConstructor<CallOptions, OutputMessageType>) {
+    this.cls = new cls();
+  }
+}

libs/langchain-standard-tests/src/unit_tests/chat_models.ts

@@ -1 +1,190 @@
-export {};
+import { expect } from "@jest/globals";
+import { BaseChatModelsTests, BaseChatModelsTestsFields } from "../base.js";
+import {
+  BaseChatModelCallOptions,
+  LangSmithParams,
+} from "@langchain/core/language_models/chat_models";
+import { BaseMessage, BaseMessageChunk } from "@langchain/core/messages";
+import { z } from "zod";
+import { StructuredTool } from "@langchain/core/tools";
+import { ChatResult } from "@langchain/core/outputs";
+import { CallbackManagerForLLMRun } from "@langchain/core/callbacks/manager";
+
+const person = z
+  .object({
+    name: z.string().describe("Name of the person"),
+    age: z.number().int().positive().describe("Age of the person"),
+  })
+  .describe("A person");
+
+class PersonTool extends StructuredTool {
+  name = "PersonTool";
+
+  description = person.description ?? "description";
+
+  schema = person;
+
+  async _call(input: z.infer<typeof person>) {
+    return JSON.stringify(input);
+  }
+}
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+type RecordStringAny = Record<string, any>;
+
+export class ChatModelUnitTests<
+  CallOptions extends BaseChatModelCallOptions = BaseChatModelCallOptions,
+  OutputMessageType extends BaseMessageChunk = BaseMessageChunk
+> extends BaseChatModelsTests<CallOptions, OutputMessageType> {
+  constructor(
+    fields: BaseChatModelsTestsFields<CallOptions, OutputMessageType>
+  ) {
+    super(fields);
+  }
+
+  testChatModelInit(constructorArgs: RecordStringAny) {
+    const chatModel = new this.cls(constructorArgs);
+    expect(chatModel).toBeDefined();
+  }
+
+  testChatModelInitApiKey(constructorArgs: RecordStringAny) {
+    const params = { ...constructorArgs, apiKey: "test" };
+    const chatModel = new this.cls(params);
+    expect(chatModel).toBeDefined();
+  }
+
+  testChatModelInitStreaming(constructorArgs: RecordStringAny) {
+    const params = { ...constructorArgs, streaming: true };
+    const chatModel = new this.cls(params);
+    expect(chatModel).toBeDefined();
+  }
+
+  testChatModelWithBindTools(
+    constructorArgs: RecordStringAny,
+    chatModelHasToolCalling: boolean
+  ) {
+    if (!chatModelHasToolCalling) {
+      return;
+    }
+    const chatModel = new this.cls(constructorArgs);
+    expect(chatModel.bindTools?.([new PersonTool()])).toBeDefined();
+  }
+
+  testChatModelWithStructuredOutput(
+    constructorArgs: RecordStringAny,
+    chatModelHasStructuredOutput: boolean
+  ) {
+    if (!chatModelHasStructuredOutput) {
+      return;
+    }
+    const chatModel = new this.cls(constructorArgs);
+    expect((chatModel as any).withStructuredOutput?.(person)).toBeDefined();
+  }
+
+  testStandardParams(constructorArgs: RecordStringAny) {
+    const expectedParams: LangSmithParams = {
+      ls_provider: "string",
+      ls_model_name: "string",
+      ls_model_type: "chat",
+      ls_temperature: 0,
+      ls_max_tokens: 0,
+      ls_stop: ["Array<string>"],
+    };
+    class ModelExtendsChatModel extends this.cls {
+      constructor(fields: RecordStringAny) {
+        super(fields);
+      }
+
+      _llmType(): string {
+        throw new Error("Method not implemented.");
+      }
+
+      _generate(
+        _messages: BaseMessage[],
+        _options: this["ParsedCallOptions"],
+        _runManager?: CallbackManagerForLLMRun | undefined
+      ): Promise<ChatResult> {
+        throw new Error("Method not implemented.");
+      }
+
+      checkLsParams(options: this["ParsedCallOptions"]) {
+        const lsParams = this.getLsParams(options);
+        return lsParams;
+      }
+    }
+    const extendedModel = new ModelExtendsChatModel(constructorArgs);
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const lsParams = extendedModel.checkLsParams({} as any);
+    expect(lsParams).toBeDefined();
+    expect(Object.keys(lsParams).sort()).toEqual(
+      Object.keys(expectedParams).sort()
+    );
+  }
+
+  /**
+   * Run all unit tests for the chat model.
+   * Each test is wrapped in a try/catch block to prevent the entire test suite from failing.
+   * If a test fails, the error is logged to the console, and the test suite continues.
+   * @param {RecordStringAny} constructorArgs The arguments to pass to the chat model constructor.
+   * @param {boolean} chatModelHasToolCalling Whether the chat model has a tool calling method.
+   * @param {boolean} chatModelHasStructuredOutput Whether the chat model has a structured output method.
+   * @returns {void}
+   */
+  runTests(
+    constructorArgs: RecordStringAny,
+    chatModelHasToolCalling: boolean,
+    chatModelHasStructuredOutput: boolean
+  ) {
+    try {
+      this.testChatModelInit(constructorArgs);
+    } catch (e) {
+      console.error("'testChatModelInit' FAILED\n");
+      console.error(e);
+      console.error("\n");
+    }
+
+    try {
+      this.testChatModelInitApiKey(constructorArgs);
+    } catch (e) {
+      console.error("'testChatModelInitApiKey' FAILED\n");
+      console.error(e);
+      console.error("\n");
+    }
+
+    try {
+      this.testChatModelInitStreaming(constructorArgs);
+    } catch (e) {
+      console.error("'testChatModelInitStreaming' FAILED\n");
+      console.error(e);
+      console.error("\n");
+    }
+
+    try {
+      this.testChatModelWithBindTools(constructorArgs, chatModelHasToolCalling);
+    } catch (e) {
+      console.error("'testChatModelWithBindTools' FAILED\n");
+      console.error(e);
+      console.error("\n");
+    }
+
+    try {
+      this.testChatModelWithStructuredOutput(
+        constructorArgs,
+        chatModelHasStructuredOutput
+      );
+    } catch (e) {
+      console.error("'testChatModelWithStructuredOutput' FAILED\n");
+      console.error(e);
+      console.error("\n");
+    }
+
+    try {
+      this.testStandardParams(constructorArgs);
+    } catch (e) {
+      console.error("'testStandardParams' FAILED\n");
+      console.error(e);
+      console.error("\n");
+    }
+  }
+}

yarn.lock

@@ -10215,6 +10215,7 @@ __metadata:
     rollup: ^4.5.2
     ts-jest: ^29.1.0
     typescript: ^5.4.5
+    zod: ^3.22.4
   languageName: unknown
   linkType: soft