feat: export parser sessions from the browser

src/worker/onenote.client.ts

@@ -1,10 +1,12 @@
 import type {
+  ExportWorkerResponse,
   PageWorkerResponse,
   ParseWorkerRequest,
   ParseWorkerResponse,
   ResourceWorkerResponse,
   WorkerRequest,
   WorkerCabinetPart,
+  WorkerExportFormat,
   WorkerFailure,
   WorkerResponse,
 } from './worker-protocol.js';
@@ -20,7 +22,11 @@ export interface WorkerPort {
 
 type PendingRequest = {
   resolve: (
-    response: ParseWorkerResponse | PageWorkerResponse | ResourceWorkerResponse
+    response:
+      | ParseWorkerResponse
+      | PageWorkerResponse
+      | ResourceWorkerResponse
+      | ExportWorkerResponse
   ) => void;
   reject: (error: WorkerClientError) => void;
 };
@@ -172,6 +178,34 @@ export class OneNoteWorkerClient {
     });
   }
 
+  exportSession(
+    sessionId: string,
+    format: WorkerExportFormat
+  ): Promise<ExportWorkerResponse> {
+    if (this.terminated) {
+      return Promise.reject(
+        new WorkerClientError(
+          'worker-failure',
+          'The local parser worker has already been terminated.'
+        )
+      );
+    }
+
+    const requestId = `export-${++this.requestSequence}`;
+    return new Promise((resolve, reject) => {
+      this.pending.set(requestId, {
+        resolve: (response) => resolve(response as ExportWorkerResponse),
+        reject,
+      });
+      this.worker.postMessage({
+        type: 'export-session',
+        requestId,
+        sessionId,
+        format,
+      });
+    });
+  }
+
   terminate(): void {
     if (this.terminated) return;
     this.terminated = true;