NodeJS Plugin Runtime (#53)

plugin-runtime/src/PluginHandle.ts

@@ -0,0 +1,90 @@
+import { randomUUID } from 'node:crypto';
+import { Worker } from 'node:worker_threads';
+import { PluginInfo } from './plugins';
+
+export interface ParentToWorkerEvent<T = any> {
+  callbackId: string;
+  name: string;
+  payload: T;
+}
+
+export type WorkerToParentSuccessEvent<T> = {
+  callbackId: string;
+  payload: T;
+};
+
+export type WorkerToParentErrorEvent = {
+  callbackId: string;
+  error: string;
+};
+
+export type WorkerToParentEvent<T = any> = WorkerToParentErrorEvent | WorkerToParentSuccessEvent<T>;
+
+export class PluginHandle {
+  readonly pluginDir: string;
+  readonly #worker: Worker;
+
+  constructor({ pluginDir, workerJsPath }: { pluginDir: string; workerJsPath: string }) {
+    this.pluginDir = pluginDir;
+
+    this.#worker = new Worker(workerJsPath, {
+      workerData: {
+        pluginDir: this.pluginDir,
+      },
+    });
+
+    this.#worker.on('error', this.#handleError.bind(this));
+    this.#worker.on('exit', this.#handleExit.bind(this));
+  }
+
+  async getInfo(): Promise<PluginInfo> {
+    return this.#callPlugin('info', null);
+  }
+
+  async runResponseFilter({ filter, body }: { filter: string; body: string }): Promise<string> {
+    return this.#callPlugin('run-filter', { filter, body });
+  }
+
+  async runExport(request: any): Promise<string> {
+    return this.#callPlugin('run-export', request);
+  }
+
+  async runImport(data: string): Promise<string> {
+    const result = await this.#callPlugin('run-import', data);
+
+    // Plugin returns object, but we convert to string
+    return JSON.stringify(result, null, 2);
+  }
+
+  #callPlugin<P, R>(name: string, payload: P): Promise<R> {
+    const callbackId = `cb_${randomUUID().replaceAll('-', '')}`;
+    return new Promise((resolve, reject) => {
+      const cb = (e: WorkerToParentEvent<R>) => {
+        if (e.callbackId !== callbackId) return;
+
+        if ('error' in e) {
+          reject(e.error);
+        } else {
+          resolve(e.payload as R);
+        }
+
+        this.#worker.removeListener('message', cb);
+      };
+
+      this.#worker.addListener('message', cb);
+      this.#worker.postMessage({ callbackId, name, payload });
+    });
+  }
+
+  async #handleError(err: Error) {
+    console.error('PLUGIN ERROR', this.pluginDir, err);
+  }
+
+  async #handleExit(code: number) {
+    if (code === 0) {
+      console.log('PLUGIN EXITED SUCCESSFULLY');
+    } else {
+      console.log('PLUGIN EXITED CODE', code);
+    }
+  }
+}