Require sharp from the main thread to prevent issues on worker exit

packages/transformers/image/package.json

@@ -17,6 +17,7 @@
  },
  "dependencies": {
  "@parcel/plugin": "2.0.0-rc.0",
+ "@parcel/workers": "2.0.0-rc.0",
  "nullthrows": "^1.1.1"
  },
  "devDependencies": {

packages/transformers/image/src/ImageTransformer.js

@@ -2,6 +2,8 @@
 import {validateConfig} from './validateConfig';
 import {Transformer} from '@parcel/plugin';
 import nullthrows from 'nullthrows';
+import WorkerFarm from '@parcel/workers';
+import loadSharp from './loadSharp';
 
 // from https://github.com/lovell/sharp/blob/df7b8ba73808fc494be413e88cfb621b6279218c/lib/output.js#L6-L17
 const FORMATS = new Map([
@@ -16,7 +18,7 @@ const FORMATS = new Map([
  ['heif', 'heif'],
 ]);
 
-const SHARP_RANGE = '^0.29.1';
+let isSharpLoadedOnMainThread = false;
 
 export default (new Transformer({
  async loadConfig({config}) {
@@ -61,14 +63,28 @@ export default (new Transformer({
  const outputOptions = config[format];
 
  if (width || height || quality || targetFormat || outputOptions) {
+ // Sharp must be required from the main thread as well to prevent errors when workers exit
+ // See https://sharp.pixelplumbing.com/install#worker-threads and https://github.com/lovell/sharp/issues/2263
+ if (WorkerFarm.isWorker() && !isSharpLoadedOnMainThread) {
+ let api = WorkerFarm.getWorkerApi();
+ await api.callMaster({
+ location: __dirname + '/loadSharp.js',
+ args: [
+ options.packageManager,
+ asset.filePath,
+ options.shouldAutoInstall,
+ ],
+ });
+
+ isSharpLoadedOnMainThread = true;
+ }
+
  let inputBuffer = await asset.getBuffer();
- let sharp = await options.packageManager.require(
- 'sharp',
+ let sharp = await loadSharp(
+ options.packageManager,
  asset.filePath,
- {
- range: SHARP_RANGE,
- shouldAutoInstall: options.shouldAutoInstall,
- },
+ options.shouldAutoInstall,
+ true,
  );
 
  let imagePipeline = sharp(inputBuffer);

packages/transformers/image/src/loadSharp.js

@@ -0,0 +1,23 @@
+// @flow
+import type {PackageManager} from '@parcel/package-manager';
+import type {FilePath} from '@parcel/types';
+
+const SHARP_RANGE = '^0.29.1';
+
+// This is used to load sharp on the main thread, which prevents errors when worker threads exit
+// See https://sharp.pixelplumbing.com/install#worker-threads and https://github.com/lovell/sharp/issues/2263
+module.exports = async (
+ packageManager: PackageManager,
+ filePath: FilePath,
+ shouldAutoInstall: boolean,
+ shouldReturn: boolean,
+): Promise<any> => {
+ let sharp = await packageManager.require('sharp', filePath, {
+ range: SHARP_RANGE,
+ shouldAutoInstall: shouldAutoInstall,
+ });
+
+ if (shouldReturn) {
+ return sharp;
+ }
+};