Function processImageInWorker

services/workerService.ts:48–119

(
  file: File,
  config: OptimizerConfiguration,
)

 * Wraps the Worker's event-based API in a clean Promise.
 */
export const processImageInWorker = (
  file: File,
  config: OptimizerConfiguration,
): Promise<{buffer: ArrayBuffer; time: number}> => {
  // Executor function must be synchronous. We wrap async logic in an IIFE.
  return new Promise((resolve, reject) => {
    const worker = getWorkerFromPool();

    // Register the task as active
    activeTasks.set(worker, {resolve, reject});

    // Use 'void' to satisfy @typescript-eslint/no-floating-promises
    void (async () => {
      try {
        const buffer = await file.arrayBuffer();

        // Check if cancelled during the async arrayBuffer read
        if (!activeTasks.has(worker)) {
          // Task was cancelled externally.
          return;
        }

        // Listen for the worker's reply
        worker.onmessage = (event: MessageEvent<WorkerResponseMessage>) => {
          const {type, buffer: resBuffer, time, message, details} = event.data;

          if (activeTasks.has(worker)) {
            if (type === 'SUCCESS' && resBuffer) {
              activeTasks.delete(worker);
              resolve({buffer: resBuffer, time: time || 0});
              returnWorkerToPool(worker);
            } else if (type === 'ERROR') {
              activeTasks.delete(worker);
              console.error('[Worker Error Details]:', details);
              reject(new Error(message || 'Unknown worker error'));
              returnWorkerToPool(worker);
            } else if (type === 'LOG') {
              console.debug(message, details);
            }
          }
        };

        // Handle crashes
        worker.onerror = error => {
          if (activeTasks.has(worker)) {
            activeTasks.delete(worker);
            console.error('Worker Global Error', error);
            reject(error);
            worker.terminate(); // Kill dead workers
          }
        };

        // Send data to worker
        worker.postMessage(
          {
            buffer,
            fileType: file.type,
            config,