🐛 Not displaying or honoring Typescript errors

Using a minimal typescript project, parcel will not display errors that typescript catches.

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

Babel is not used in the example I gave but could be easily put in.

🤔 Expected Behavior

parcel should display errors caught by typescript in two places.

1. In the CLI
2. On the web page, either as an overlay or in the console

Also, parcel should honor noEmitOnError in tsconfig.json and not output compiled code if an error is found when running parcel build

😯 Current Behavior

No errors are displayed and the project builds even when noEmitOnError is set to true

🔦 Context

I have been trying to integrate parcel with a medium size typescript project I have, however it swallows typescript errors.

💻 Code Sample

https://github.com/kaw2k/parcel-typescript-errors

🌍 Your Environment

Software	Version(s)
Parcel	v1.4.1
Node	v8.2.1
npm/Yarn	Yarn
Operating System	OSX High Sierra

[Offirmo]

Why closing this request?

Ignoring errors defeats the puprose of using TypeScript. Thus the advertised TypeScript “support” is misleading.

[nexussays]

If it helps anyone else, this is the workaround I came up with after reading through this issue and all the other ones related to Typescript support trying to find a solution.

Use the concurrently package (npm i -D concurrently) and then in package.json:

"scripts": {
   "dev": "concurrently --kill-others \"npm:compile:watch\" \"npm:dev:server\"",
   "dev:server": "parcel ./src/index.html --https --out-dir artifacts/obj",
   "compile:watch": "tsc -p . --noEmit --watch",
}

Then npm run dev will output something like:

01:20:35 - File change detected. Starting incremental compilation...
[compile:watch] 01:20:35 - Found 0 errors. Watching for file changes.
[dev:server] √  Built in 605ms.

01:20:55 - File change detected. Starting incremental compilation...
[dev:server] √  Built in 637ms.
[compile:watch] src/components/AppRoot.tsx(69,14): error TS2304: Cannot find name 'Counter'.
[compile:watch] 01:20:55 - Found 1 error. Watching for file changes.

It doesn’t fail the Parcel build, but I personally don’t care as it only takes a few hundred milliseconds.