fix(langchain): make core a workspace peer dep (#9487)

Author: hntrl

.changeset/khaki-toes-flow.md

@@ -0,0 +1,5 @@
+---
+"langchain": patch
+---
+
+constrain lower bound core peer dep

dependency_range_tests/docker-compose.yml

@@ -9,6 +9,7 @@ services:
     working_dir: /app
     volumes:
       - ../libs/langchain:/langchain
+      - ../libs/langchain-core:/libs/langchain-core
       - ../libs/langchain-textsplitters:/libs/langchain-textsplitters
       - ../libs/providers/langchain-openai:/libs/langchain-openai
       - ../libs/providers/langchain-anthropic:/libs/langchain-anthropic

dependency_range_tests/scripts/langchain/node/update_resolutions_latest.js

@@ -8,33 +8,16 @@ currentPackageJson.pnpm = { overrides: {} };
 
 const INTERNAL_PACKAGES = ["@langchain/eslint"];
 
-if (
-  currentPackageJson.peerDependencies?.["@langchain/core"] &&
-  !currentPackageJson.peerDependencies["@langchain/core"].includes("rc")
-) {
-  currentPackageJson.peerDependencies = {
-    ...currentPackageJson.peerDependencies,
-  };
-}
-
 /**
  * Link workspace dependencies via file path
  */
 const workspaceDependencies = [
   ...Object.entries(currentPackageJson.devDependencies),
+  ...Object.entries(currentPackageJson.peerDependencies),
   ...Object.entries(currentPackageJson.dependencies),
 ].filter(([, depVersion]) => depVersion.includes("workspace:"));
 
 for (const [depName, depVersion] of workspaceDependencies) {
-  /**
-   * for the peer dependency @langchain/core, we want to make sure to install max version
-   * defined above
-   */
-  if (depName === "@langchain/core") {
-    delete currentPackageJson.devDependencies[depName];
-    continue;
-  }
-
   const libName = depName.split("/")[1];
 
   if (INTERNAL_PACKAGES.includes(depName)) {

dependency_range_tests/scripts/langchain/node/update_resolutions_lowest.js

@@ -1,5 +1,4 @@
 const fs = require("fs");
-const semver = require("semver");
 
 const communityPackageJsonPath = "package.json";
 
@@ -10,37 +9,16 @@ const currentPackageJson = JSON.parse(
 );
 currentPackageJson.pnpm = { overrides: {} };
 
-if (
-  currentPackageJson.peerDependencies?.["@langchain/core"] &&
-  !currentPackageJson.peerDependencies["@langchain/core"].includes("rc")
-) {
-  const minVersion = semver.minVersion(
-    currentPackageJson.peerDependencies["@langchain/core"]
-  ).version;
-  currentPackageJson.peerDependencies = {
-    ...currentPackageJson.peerDependencies,
-    "@langchain/core": minVersion,
-  };
-}
-
 /**
  * Convert workspace dev dependencies to install latest as they are only used for testing
  */
 const workspaceDependencies = [
   ...Object.entries(currentPackageJson.devDependencies),
+  ...Object.entries(currentPackageJson.peerDependencies),
   ...Object.entries(currentPackageJson.dependencies),
 ].filter(([, depVersion]) => depVersion.includes("workspace:"));
 
 for (const [depName, depVersion] of workspaceDependencies) {
-  /**
-   * for the peer dependency @langchain/core, we want to make sure to install min version
-   * defined above
-   */
-  if (depName === "@langchain/core") {
-    delete currentPackageJson.devDependencies[depName];
-    continue;
-  }
-
   const libName = depName.split("/")[1];
 
   if (INTERNAL_PACKAGES.includes(depName)) {

libs/langchain/package.json

@@ -74,7 +74,7 @@
     "yaml": "^2.8.1"
   },
   "peerDependencies": {
-    "@langchain/core": "^1.0.5"
+    "@langchain/core": "workspace:*"
   },
   "dependencies": {
     "@langchain/langgraph": "^1.0.0",

libs/langchain/src/agents/tests/systemMessage.test.ts

@@ -1,4 +1,11 @@
-import { describe, it, expect, vi, type MockInstance } from "vitest";
+import {
+  describe,
+  it,
+  expect,
+  beforeEach,
+  vi,
+  type MockInstance,
+} from "vitest";
 import {
   HumanMessage,
   BaseMessage,