FileExists is not defined error when trying to install qCalendar using webpack

[lukagrahor]

Describe the bug
The bug that was marked as solved here is still occurring to me: New release 4.00 broken when running in dev just after install as extension. When installing the plugin, the installation fails with the error: ReferenceError: fileExists is not defined.

To Reproduce
Steps to reproduce the behavior:

1. Go to quasar project directory
2. Run quasar ext add @quasar/qcalendar
3. See error:
   App • Updating /quasar.extensions.json for "@quasar/qcalendar" extension ...
   D:\Projects\kiosk-quasar-v2\node_modules@quasar\app-webpack\lib\app-extension\create-app-ext.js:29
   stringifyJSON(json, { indent: fileExists ? undefined : 2 }),
   ^
   ReferenceError: fileExists is not defined
   at save (D:\Projects\kiosk-quasar-v2\node_modules@quasar\app-webpack\lib\app-extension\create-app-ext.js:29:37)
   at Object.set (D:\Projects\kiosk-quasar-v2\node_modules@quasar\app-webpack\lib\app-extension\create-app-ext.js:43:7)
   at AppExtensionInstance.install (D:\Projects\kiosk-quasar-v2\node_modules@quasar\app-webpack\lib\app-extension\AppExtensionInstance.js:235:22)
   at async runExtAction (D:\Projects\kiosk-quasar-v2\node_modules@quasar\app-webpack\lib\cmd\ext.js:69:3)
   Node.js v20.18.0

Expected behavior
The plugin should have installed into my project.

Screenshots

QCalendar:

• Version 4.1.0

Desktop (please complete the following information):

• OS: Windows
• Browser ---
• Version ---

Smartphone (please complete the following information):

• Device: ---
• OS: ---
• Browser ---
• Version ---

Additional context
package.json:
{
"name": "quasar-project",
"version": "0.0.1",
"description": "A Quasar Project",
"productName": "Quasar App",
"author": "abc[email protected]",
"private": true,
"type": "module",
"scripts": {
"lint": "eslint -c ./eslint.config.js "./src*//*.{js,cjs,mjs,vue}"",
"format": "prettier --write "/*.{js,vue,scss,html,md,json}" --ignore-path .gitignore",
"test": "echo "No test specified" && exit 0",
"dev": "quasar dev",
"build": "quasar build",
"postinstall": "quasar prepare"
},
"dependencies": {
"@quasar/extras": "^1.16.4",
"axios": "^1.2.1",
"core-js": "^3.31.1",
"pinia": "^2.0.11",
"quasar": "^2.16.0",
"vue": "^3.4.18",
"vue-i18n": "^9.0.0",
"vue-router": "^4.0.12"
},
"devDependencies": {
"@eslint/js": "^9.14.0",
"@quasar/app-webpack": "^4.0.8",
"@vue/eslint-config-prettier": "^10.1.0",
"autoprefixer": "^10.4.2",
"eslint": "^9.14.0",
"eslint-plugin-vue": "^9.30.0",
"eslint-webpack-plugin": "^4.2.0",
"globals": "^15.12.0",
"prettier": "^3.3.3"
},
"browserslist": [
"last 10 Chrome versions",
"last 10 Firefox versions",
"last 4 Edge versions",
"last 7 Safari versions",
"last 8 Android versions",
"last 8 ChromeAndroid versions",
"last 8 FirefoxAndroid versions",
"last 10 iOS versions",
"last 5 Opera versions"
],
"engines": {
"node": "^28 || ^26 || ^24 || ^22 || ^20 || ^18",
"npm": ">= 6.13.4",
"yarn": ">= 1.21.1"
}
}

[hawkeye64]

This is a known issue with app-webpack (cannot install app extensions). The fix is in, it just needs to be merged and released.
@rstoenescu

[github-actions]

Bumping this issue because it has been open for 7 days with no activity. Closing automatically in 7 days unless it becomes active again.

[hawkeye64]

Closing this one as it's a Quasar issue: quasarframework/quasar#17797