feat(scripts): automatic tsup migration

langchain-core/package.json

@@ -28,7 +28,8 @@
     "test:watch": "NODE_OPTIONS=--experimental-vm-modules jest --watch --testPathIgnorePatterns=\\.int\\.test.ts",
     "test:single": "NODE_OPTIONS=--experimental-vm-modules yarn run jest --config jest.config.cjs --testTimeout 100000",
     "format": "prettier --config .prettierrc --write \"src\"",
-    "format:check": "prettier --config .prettierrc --check \"src\""
+    "format:check": "prettier --config .prettierrc --check \"src\"",
+    "type-check": "tsc --noEmit"
   },
   "author": "LangChain",
   "license": "MIT",
@@ -68,7 +69,8 @@
     "release-it": "^18.1.2",
     "rimraf": "^5.0.1",
     "ts-jest": "^29.1.0",
-    "typescript": "~5.1.6",
+    "tsup": "^8.4.0",
+    "typescript": "^5.4.5",
     "web-streams-polyfill": "^4.0.0"
   },
   "publishConfig": {

langchain-core/src/messages/content_blocks.ts

@@ -228,7 +228,7 @@ export function parseBase64DataUrl({
  */
 export function parseBase64DataUrl({
   dataUrl,
-  asTypedArray = false,
+  asTypedArray,
 }: {
   dataUrl: string;
   asTypedArray?: false;
@@ -243,7 +243,7 @@ export function parseBase64DataUrl({
  */
 export function parseBase64DataUrl({
   dataUrl: data_url,
-  asTypedArray = false,
+  asTypedArray,
 }: {
   dataUrl: string;
   asTypedArray?: boolean;

langchain-core/tsconfig.json

@@ -1,5 +1,5 @@
 {
-  "extends": "@tsconfig/recommended",
+  "extends": "@tsconfig/recommended/tsconfig.json",
   "compilerOptions": {
     "outDir": "../dist",
     "rootDir": "./src",
@@ -9,7 +9,7 @@
       "ES2022.Object",
       "DOM"
     ],
-    "module": "ES2020",
+    "module": "NodeNext",
     "moduleResolution": "nodenext",
     "esModuleInterop": true,
     "declaration": true,
@@ -30,4 +30,4 @@
     "dist",
     "docs"
   ]
-}
+}

langchain-core/tsup.config.ts

@@ -0,0 +1,87 @@
+import { defineConfig } from "tsup";
+export default defineConfig({
+  // Entry points - adjust for your package structure
+  entry: [
+    "src/agents.ts",
+    "src/caches/base.ts",
+    "src/callbacks/base.ts",
+    "src/callbacks/dispatch/index.ts",
+    "src/callbacks/dispatch/web.ts",
+    "src/callbacks/manager.ts",
+    "src/callbacks/promises.ts",
+    "src/chat_history.ts",
+    "src/context.ts",
+    "src/documents/index.ts",
+    "src/document_loaders/base.ts",
+    "src/document_loaders/langsmith.ts",
+    "src/embeddings.ts",
+    "src/example_selectors/index.ts",
+    "src/indexing/index.ts",
+    "src/language_models/base.ts",
+    "src/language_models/chat_models.ts",
+    "src/language_models/llms.ts",
+    "src/load/index.ts",
+    "src/load/serializable.ts",
+    "src/memory.ts",
+    "src/messages/index.ts",
+    "src/messages/tool.ts",
+    "src/output_parsers/index.ts",
+    "src/output_parsers/openai_tools/index.ts",
+    "src/output_parsers/openai_functions/index.ts",
+    "src/outputs.ts",
+    "src/prompts/index.ts",
+    "src/prompt_values.ts",
+    "src/runnables/index.ts",
+    "src/runnables/graph.ts",
+    "src/runnables/remote.ts",
+    "src/retrievers/index.ts",
+    "src/retrievers/document_compressors/base.ts",
+    "src/singletons/index.ts",
+    "src/stores.ts",
+    "src/structured_query/index.ts",
+    "src/tools/index.ts",
+    "src/tracers/base.ts",
+    "src/tracers/console.ts",
+    "src/tracers/initialize.ts",
+    "src/tracers/log_stream.ts",
+    "src/tracers/run_collector.ts",
+    "src/tracers/tracer_langchain.ts",
+    "src/tracers/tracer_langchain_v1.ts",
+    "src/types/stream.ts",
+    "src/utils/async_caller.ts",
+    "src/utils/chunk_array.ts",
+    "src/utils/env.ts",
+    "src/utils/event_source_parse.ts",
+    "src/utils/function_calling.ts",
+    "src/utils/hash.ts",
+    "src/utils/json_patch.ts",
+    "src/utils/json_schema.ts",
+    "src/utils/math.ts",
+    "src/utils/stream.ts",
+    "src/utils/testing/index.ts",
+    "src/utils/tiktoken.ts",
+    "src/utils/types/index.ts",
+    "src/vectorstores.ts",
+  ],
+  // Output both ESM and CJS formats
+  format: ["esm", "cjs"],
+  // Generate declaration files
+  dts: true,
+  // enable treeshaking
+  treeshake: "safest",
+  // Generate sourcemaps
+  sourcemap: true,
+  // Clean output directory before build
+  clean: true,
+  // Specify output directory
+  outDir: "dist",
+  // Set output extension based on format
+  outExtension({ format }) {
+    return {
+      js: format === "esm" ? ".js" : ".cjs",
+    };
+  },
+  // Ensure all external dependencies are properly excluded from the bundle
+  // These will be taken from package.json dependencies/peerDependencies
+  external: [],
+});

libs/langchain-scripts/README.md

@@ -7,3 +7,54 @@ This package contains the LangChain.js shared scripts for our packages.
 ```bash npm2yarn
 npm install @langchain/scripts
 ```
+
+## Usage
+
+### Build Script
+
+The build script supports both traditional TypeScript compilation and modern tsup-based builds.
+
+```bash
+npx lc_build
+```
+
+#### Traditional TypeScript Build
+
+By default, the build script uses TypeScript's compiler (tsc) to build both ESM and CJS versions of your package.
+
+#### tsup-based Build
+
+The build script can also use [tsup](https://github.com/egoist/tsup) (a zero-config TypeScript bundler powered by esbuild) which offers significant performance improvements (10-100x faster builds).
+
+To migrate your package to use tsup:
+
+```bash
+npx lc_build --migrate-build
+```
+
+This command performs several migration steps:
+1. Creates a `tsup.config.ts` file with sensible defaults for LangChain packages
+2. Updates TypeScript to the latest version in your package.json
+3. Ensures your package.json has a `type-check` script
+4. Backs up the tsconfig.cjs.json file (which is no longer needed with tsup)
+5. Provides guidance on updating build scripts if needed
+
+After migration, simply run the build script normally:
+
+```bash
+npx lc_build
+```
+
+The script will automatically detect the presence of a tsup configuration file and use it for building.
+
+### Notebooks Type-Checking
+
+```bash
+npx notebook_validate
+```
+
+### Serialized Field Extraction 
+
+```bash
+npx extract_serializable_fields
+```

libs/langchain-scripts/package.json

@@ -21,8 +21,9 @@
   },
   "scripts": {
     "build": "yarn clean && yarn turbo:command build:internal --filter=@langchain/scripts",
-    "build:internal": "tsc --project ./tsconfig.build.json && yarn move:artifacts && yarn build:generated",
-    "move:artifacts": "rimraf dist && mkdir -p dist && mv dist_build/* dist/",
+    "build:internal": "tsc --project ./tsconfig.build.json && yarn move:artifacts && yarn build:generated && yarn copy:template",
+    "move:artifacts": "rimraf dist && mkdir -p dist/build && cp -r dist_build/* dist/ && rimraf dist_build",
+    "copy:template": "cp src/build/tsup.config.template.ts dist/build/",
     "build:generated": "node bin/build.js --create-entrypoints --pre --tree-shaking",
     "build:turbo": "yarn turbo:command build --filter=@langchain/scripts",
     "lint:eslint": "NODE_OPTIONS=--max-old-space-size=4096 eslint --cache --ext .ts,.js src/",
@@ -37,7 +38,8 @@
     "test:int": "NODE_OPTIONS=--experimental-vm-modules jest --testPathPattern=\\.int\\.test.ts --testTimeout 100000 --maxWorkers=50%",
     "format": "prettier --write \"src\"",
     "format:check": "prettier --check \"src\"",
-    "create:integration:doc": "node dist/cli/docs/index.js"
+    "create:integration:doc": "node dist/cli/docs/index.js",
+    "check:types": "tsc --noEmit"
   },
   "author": "LangChain",
   "license": "MIT",
@@ -52,13 +54,14 @@
     "rimraf": "^5.0.1",
     "rollup": "^4.5.2",
     "ts-morph": "^21.0.1",
+    "tsup": "^8.4.0",
     "typescript": "^5.4.5"
   },
   "devDependencies": {
     "@jest/globals": "^29.5.0",
     "@swc/core": "^1.3.90",
     "@swc/jest": "^0.2.29",
-    "@tsconfig/recommended": "^1.0.3",
+    "@tsconfig/recommended": "^1.0.8",
     "@types/lodash": "^4",
     "@typescript-eslint/eslint-plugin": "^6.12.0",
     "@typescript-eslint/parser": "^6.12.0",