only require and process using sharp when really required (#4976)

packages/transformers/image/package.json

@@ -16,7 +16,9 @@
  "parcel": "^2.0.0-beta.1"
  },
  "dependencies": {
- "@parcel/plugin": "^2.0.0-beta.1",
+ "@parcel/plugin": "^2.0.0-beta.1"
+ },
+ "devDependencies": {
  "sharp": "^0.24.1"
  }
 }

packages/transformers/image/src/ImageTransformer.js

@@ -1,6 +1,5 @@
 // @flow
 import {Transformer} from '@parcel/plugin';
-import sharp from 'sharp';
 
 const FORMATS = new Map([
  ['heic', 'heif'],
@@ -14,35 +13,46 @@ const FORMATS = new Map([
 ]);
 
 export default (new Transformer({
- async transform({asset}) {
+ async transform({asset, options}) {
  asset.isIsolated = true;
 
- let inputBuffer = await asset.getBuffer();
  let width = asset.query.width ? parseInt(asset.query.width, 10) : null;
  let height = asset.query.height ? parseInt(asset.query.height, 10) : null;
  let quality = asset.query.quality
  ? parseInt(asset.query.quality, 10)
  : undefined;
  let format = asset.query.as ? asset.query.as.toLowerCase().trim() : null;
 
- let imagePipeline = sharp(inputBuffer);
- if (width || height) {
- imagePipeline.resize(width, height);
- }
-
- if (format) {
- if (!FORMATS.has(format)) {
- throw new Error(`Sharp does not support ${format} images.`);
+ if (width || height || quality || format) {
+ const sharp = await options.packageManager.require(
+ 'sharp',
+ asset.filePath,
+ {
+ // Sharp takes too long to install for autoinstall option to make sense
+ autoinstall: false,
+ },
+ );
+
+ let inputBuffer = await asset.getBuffer();
+ let imagePipeline = sharp(inputBuffer);
+ if (width || height) {
+ imagePipeline.resize(width, height);
  }
 
- asset.type = format;
+ if (format) {
+ if (!FORMATS.has(format)) {
+ throw new Error(`Sharp does not support ${format} images.`);
+ }
 
- imagePipeline[FORMATS.get(format)]({
- quality,
- });
- }
+ asset.type = format;
 
- asset.setStream(imagePipeline);
+ imagePipeline[FORMATS.get(format)]({
+ quality,
+ });
+ }
+
+ asset.setStream(imagePipeline);
+ }
 
  return [asset];
  },