fix(langchain): Fix Groq import for hub (#7620)

langchain/src/hub/base.ts

@@ -96,10 +96,6 @@ export function generateModelImportMap(
 ) {
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   const modelImportMap: Record<string, any> = {};
-  // TODO: Fix in 0.4.0. We can't get lc_id without instantiating the class, so we
-  // must put them inline here. In the future, make this less hacky
-  // This should probably use dynamic imports and have a web-only entrypoint
-  // in a future breaking release
   if (modelClass !== undefined) {
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     const modelLcName = (modelClass as any)?.lc_name();
@@ -130,3 +126,29 @@ export function generateModelImportMap(
   }
   return modelImportMap;
 }
+
+export function generateOptionalImportMap(
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  modelClass?: new (...args: any[]) => BaseLanguageModel
+) {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  const optionalImportMap: Record<string, any> = {};
+  if (modelClass !== undefined) {
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const modelLcName = (modelClass as any)?.lc_name();
+    let optionalImportMapKey;
+    if (modelLcName === "ChatGoogleGenerativeAI") {
+      optionalImportMapKey = "langchain_google_genai/chat_models";
+    } else if (modelLcName === "ChatBedrockConverse") {
+      optionalImportMapKey = "langchain_aws/chat_models";
+    } else if (modelLcName === "ChatGroq") {
+      optionalImportMapKey = "langchain_groq/chat_models";
+    }
+    if (optionalImportMapKey !== undefined) {
+      optionalImportMap[optionalImportMapKey] = {
+        [modelLcName]: modelClass,
+      };
+    }
+  }
+  return optionalImportMap;
+}

langchain/src/hub/index.ts

@@ -1,7 +1,12 @@
 import { Runnable } from "@langchain/core/runnables";
 import type { BaseLanguageModel } from "@langchain/core/language_models/base";
 import { load } from "../load/index.js";
-import { basePush, basePull, generateModelImportMap } from "./base.js";
+import {
+  basePush,
+  basePull,
+  generateModelImportMap,
+  generateOptionalImportMap,
+} from "./base.js";
 
 export { basePush as push };
 
@@ -36,7 +41,7 @@ export async function pull<T extends Runnable>(
     const loadedPrompt = await load<T>(
       JSON.stringify(promptObject.manifest),
       undefined,
-      undefined,
+      generateOptionalImportMap(options?.modelClass),
       generateModelImportMap(options?.modelClass)
     );
     return loadedPrompt;

langchain/src/hub/node.ts

@@ -1,5 +1,10 @@
 import { Runnable } from "@langchain/core/runnables";
-import { basePush, basePull, generateModelImportMap } from "./base.js";
+import {
+  basePush,
+  basePull,
+  generateModelImportMap,
+  generateOptionalImportMap,
+} from "./base.js";
 import { load } from "../load/index.js";
 
 // TODO: Make this the default, add web entrypoint in next breaking release
@@ -55,7 +60,7 @@ export async function pull<T extends Runnable>(
   const loadedPrompt = await load<T>(
     JSON.stringify(promptObject.manifest),
     undefined,
-    undefined,
+    generateOptionalImportMap(modelClass),
     generateModelImportMap(modelClass)
   );
   return loadedPrompt;

langchain/src/hub/tests/hub.int.test.ts

@@ -79,12 +79,13 @@ test("Test LangChain Hub while loading model", async () => {
 });
 
 test("Test LangChain Hub while loading model with dynamic imports", async () => {
-  const pulledPrompt = await nodePull("jacob/lahzo-testing", {
+  const pulledPrompt = await nodePull("jacob/groq-test", {
     includeModel: true,
   });
   const res = await pulledPrompt.invoke({
-    agent: { name: "testing" },
-    messages: [new AIMessage("foo")],
+    question:
+      "Who is the current president of the USA as of today? You must use the provided tool for the latest info.",
   });
   expect(res).toBeInstanceOf(AIMessage);
+  expect(res.tool_calls?.length).toEqual(1);
 });