Watch mode issue with webextension : Cannot read properties of undefined (reading 'flatMap')

[Booteille]

🐛 bug report

Hi!

After upgrading Parcel to the latest version (2.10.0), when building my Web Extension using parcel build command, everything works fine but using the watch mode returns an error.

This one works:

$ yarn parcel build manifest.json --config @parcel/config-webextension --target webext-dev

This one returns the following error:

$ yarn parcel manifest.json --config @parcel/config-webextension --target webext-dev
yarn run v1.22.19
$ /home/booteille/Dev/peertube-companion/node_modules/.bin/parcel manifest.json --config @parcel/config-webextension --target webext-dev
Server running at http://localhost:1234
🚨 Build failed.

@parcel/transformer-webextension: Cannot read properties of undefined (reading 'flatMap')

  TypeError: Cannot read properties of undefined (reading 'flatMap')
      at collectDependencies
  (/home/booteille/Dev/peertube-companion/node_modules/@parcel/transformer-webextension/lib/WebExtensionTransformer.js:290:59)
      at async Object.transform
  (/home/booteille/Dev/peertube-companion/node_modules/@parcel/transformer-webextension/lib/WebExtensionTransformer.js:365:5)
      at async Transformation.runTransformer
  (/home/booteille/Dev/peertube-companion/node_modules/@parcel/core/lib/Transformation.js:568:5)
      at async Transformation.runPipeline
  (/home/booteille/Dev/peertube-companion/node_modules/@parcel/core/lib/Transformation.js:346:36)
      at async Transformation.runPipelines
  (/home/booteille/Dev/peertube-companion/node_modules/@parcel/core/lib/Transformation.js:229:40)
      at async Transformation.run
  (/home/booteille/Dev/peertube-companion/node_modules/@parcel/core/lib/Transformation.js:149:21)
      at async Object.run
  (/home/booteille/Dev/peertube-companion/node_modules/@parcel/core/lib/requests/AssetRequest.js:102:7)
      at async RequestTracker.runRequest
  (/home/booteille/Dev/peertube-companion/node_modules/@parcel/core/lib/RequestTracker.js:637:20)
      at async AssetGraphBuilder.runAssetRequest
  (/home/booteille/Dev/peertube-companion/node_modules/@parcel/core/lib/requests/AssetGraphRequest.js:346:18)
      at async $31bd78e367586e0a$export$2e2bcd8739ae039._runFn
  (/home/booteille/Dev/peertube-companion/node_modules/@parcel/utils/lib/index.js:34236:13)

🎛 Configuration (.babelrc, package.json, cli command)

{
  "name": "peertube-companion",
  "version": "0.3.1",
  "description": "The PeerTube Companion",
  "author": "Booteille <booteille@protonmail.com>",
  "license": "CC BY-SA 4.0",
  "private": true,
  "scripts": {
    "build:dev": "yarn clean && parcel build manifest.json --config @parcel/config-webextension --target webext-dev",
    "build:prod": "yarn clean && parcel build manifest.json --config @parcel/config-webextension --target webext-prod && yarn zip",
    "clean": "rimraf .parcel-cache dist",
    "lint": "eslint --ext .ts,.tsx,.vue src",
    "test": "jest",
    "watch": "yarn clean && parcel manifest.json --config @parcel/config-webextension --target webext-dev",
    "zip": "cd dist/webext-prod && bestzip peertube-companion.zip *",
    "zip:sources": "zip -r dist/peertube-companion-sources.zip ./ -x \"./node_modules/*\" \"./.git/*\" \"./.parcel-cache/*\" \"./dist/*\""
  },
  "targets": {
    "webext-dev": {
      "sourceMap": {
        "inline": true,
        "inlineSources": true
      }
    },
    "webext-prod": {}
  },
  "dependencies": {
    "yarn": "^1.22.19"
  },
  "devDependencies": {
    "@fortawesome/fontawesome-svg-core": "6.4.2",
    "@fortawesome/free-regular-svg-icons": "6.4.2",
    "@fortawesome/free-solid-svg-icons": "6.4.2",
    "@fortawesome/vue-fontawesome": "3.0.3",
    "@parcel/config-webextension": "2.10.0",
    "@parcel/core": "2.10.0",
    "@parcel/optimizer-data-url": "2.10.0",
    "@parcel/transformer-inline-string": "2.10.0",
    "@parcel/transformer-typescript-tsc": "2.10.0",
    "@parcel/transformer-vue": "2.10.0",
    "@peertube/peertube-types": "5.2.0",
    "@types/download": "8.0.4",
    "@types/lodash.clonedeep": "^4.5.7",
    "@types/lodash.defaultsdeep": "^4.6.7",
    "@types/lodash.get": "4.4.8",
    "@types/lodash.set": "^4.3.7",
    "@types/webextension-polyfill": "0.10.5",
    "@typescript-eslint/eslint-plugin": "6.8.0",
    "@typescript-eslint/parser": "6.8.0",
    "@vue/eslint-config-prettier": "^8.0.0",
    "@vue/eslint-config-typescript": "12.0.0",
    "bestzip": "2.2.1",
    "eslint": "8.52.0",
    "eslint-config-standard-with-typescript": "39.1.1",
    "eslint-plugin-import": "2.29.0",
    "eslint-plugin-n": "^16.0.2",
    "eslint-plugin-node": "11.1.0",
    "eslint-plugin-promise": "6.1.1",
    "eslint-plugin-vue": "9.17.0",
    "lodash.clonedeep": "^4.5.0",
    "lodash.defaultsdeep": "^4.6.1",
    "lodash.get": "4.4.2",
    "lodash.set": "4.3.2",
    "parcel": "2.10.0",
    "prettier": "3.0.3",
    "prettier-eslint": "16.1.1",
    "rimraf": "5.0.5",
    "ts-results": "^3.3.0",
    "typescript": "5.2.2",
    "vue": "3.3.6",
    "vue-eslint-parser": "9.3.2",
    "vue-tsc": "1.8.19",
    "vue3-popper": "1.5.0",
    "webextension-polyfill": "0.10.0"
  }
}

🤔 Expected Behavior

I expected parcel to work in watch mode too in this context.

😯 Current Behavior

Actually, parcel does not compile the webextension in watchmode.

💁 Possible Solution

🔦 Context

💻 Code Sample

🌍 Your Environment

Software	Version(s)
Parcel	2.10.0
Node	20.8.1
npm/Yarn	4.0.0
Operating System	Pop_OS