Compile node package to CommonJS module

Author: simolus3

packages/node/package.json

@@ -6,23 +6,25 @@
     "access": "public"
   },
   "description": "PowerSync - sync Postgres with SQLite in your Node.js app for offline-first and real-time data",
-  "main": "./lib/index.js",
-  "module": "./lib/index.js",
-  "types": "./lib/index.d.ts",
   "files": [
     "lib",
     "dist",
     "download_core.js"
   ],
   "scripts": {
     "install": "node download_core.js",
-    "build": "tsc -b",
+    "build": "tsc -b && rollup --config",
     "build:prod": "tsc -b --sourceMap false",
     "clean": "rm -rf lib dist tsconfig.tsbuildinfo dist",
     "watch": "tsc -b -w",
     "test": "vitest"
   },
   "type": "module",
+  "exports": {
+    "import": "./lib/index.js",
+    "require": "./dist/bundle.cjs",
+    "types": "./lib/index.d.ts"
+  },
   "repository": {
     "type": "git",
     "url": "git+https://github.com/powersync-ja/powersync-js.git"
@@ -34,17 +36,18 @@
   },
   "homepage": "https://docs.powersync.com/",
   "peerDependencies": {
-    "@powersync/common": "workspace:^1.22.0",
-    "@powersync/better-sqlite3": "^0.1.0"
+    "@powersync/common": "workspace:^1.22.0"
   },
   "dependencies": {
+    "@powersync/better-sqlite3": "^0.1.0",
     "@powersync/common": "workspace:*",
     "async-lock": "^1.4.0",
     "bson": "^6.6.0",
     "comlink": "^4.4.2"
   },
   "devDependencies": {
     "@types/async-lock": "^1.4.0",
+    "rollup": "4.14.3",
     "typescript": "^5.5.3",
     "vitest": "^3.0.5"
   },

packages/node/rollup.config.mjs

@@ -0,0 +1,27 @@
+const plugin = () => {
+    return {
+        name: 'mark-as-commonjs',
+        transform: (code) => {
+            return code.replace('const isCommonJsModule = false;', 'const isCommonJsModule = true;');
+        },
+    };
+};
+
+export default [
+    {
+        input: 'lib/index.js',
+        plugins: [plugin()],
+        output: {
+            file: 'dist/bundle.cjs',
+            format: 'cjs',
+        }
+    },
+    {
+        input: 'lib/db/SqliteWorker.js',
+        plugins: [plugin()],
+        output: {
+            file: 'dist/worker.cjs',
+            format: 'cjs',
+        }
+    }
+];

packages/node/src/db/BetterSQLite3DBAdapter.ts

@@ -53,7 +53,16 @@ export class BetterSQLite3DBAdapter extends BaseObserver<DBAdapterListener> impl
     }
 
     const openWorker = async (isWriter: boolean) => {
-      const worker = new Worker(new URL('./SqliteWorker.js', import.meta.url), {name: isWriter ? `write ${dbFilePath}` : `read ${dbFilePath}`});
+      const isCommonJsModule = false; // Replaced with true by rollup plugin
+      let worker: Worker;
+      const workerName = isWriter ? `write ${dbFilePath}` : `read ${dbFilePath}`;
+
+      if (isCommonJsModule) {
+        worker = new Worker(path.resolve(__dirname, 'worker.cjs'), {name: workerName});
+      } else {
+        worker = new Worker(new URL('./SqliteWorker.js', import.meta.url), {name: workerName});
+      }
+ 
       const listeners = new WeakMap<EventListenerOrEventListenerObject, (e: any) => void>();
 
       const comlink = Comlink.wrap<AsyncDatabaseOpener>({

packages/node/src/db/SqliteWorker.ts

@@ -1,3 +1,4 @@
+import * as path from 'node:path';
 import BetterSQLite3Database, { Database } from '@powersync/better-sqlite3';
 import * as Comlink from 'comlink';
 import { parentPort, threadId } from 'node:worker_threads';
@@ -97,6 +98,8 @@ class BetterSqliteWorker implements AsyncDatabaseOpener {
 }
 
 const loadExtension = (db: Database) => {
+  const isCommonJsModule = false; // Replaced with true by rollup plugin
+
   const platform = OS.platform();
   let extensionPath: string;
   if (platform === 'win32') {
@@ -109,7 +112,13 @@ const loadExtension = (db: Database) => {
     throw 'Unknown platform, PowerSync for Node.js currently supports Windows, Linux and macOS.';
   }
 
-  const resolved = url.fileURLToPath(new URL(`../${extensionPath}`, import.meta.url));
+  let resolved: string;
+  if (isCommonJsModule) {
+    resolved = path.resolve(__dirname, '../lib/', extensionPath);    
+  } else {
+    resolved = url.fileURLToPath(new URL(`../${extensionPath}`, import.meta.url));
+  }
+
   db.loadExtension(resolved, 'sqlite3_powersync_init');
 };