fix(config): remove ts-node register() call to allow custom configuration

[mlegenhausen]

Calling require('ts-node').register() to determine if typescript is available prevents the custom configuration of the register call described in the documentation. I removed the unnecessary register call and fixed the missing module.exports assignment in the documentation.

[johnjbarton]

I gather you are saying: we don't need to call register because all we have no options?

[trusktr]

The fact that Karma does this is highly bothersome: #3329

Use of ts-node is not a bad idea, but it should be optional, with some way to enable it.

[mlegenhausen]

@trusktr thanks for the example thats exactly the problem I encountered too. You can only call register() once in your whole project after that it is not possible to change the options given to the register call. The register call in your kamra.conf.ts is simply ignored cause karma already called it here. The only way to inject some other configuration is via the tsconfig.json which needs to be the top level tsconfig.json file. This is not suitable for all projects.

This will be a breaking change cause, if we remove the register call we need a karma.conf.js that calls register for us. Another solution could be to allow the injection of a tsconfig.json via a command line arg.

For me I was able to find a tsconfig.json configuration that fits karma and the rest of the project. But the way to this solution was very cumbersome.

[johnjbarton]

Please add the breaking change info

https://www.conventionalcommits.org/en/v1.0.0/

and the doc change.

[trusktr]

This would be great to merge, but then the docs also need an update on how to add TS support when that is wanted.

[trusktr]

The only easy workaround that I can think of is forking karma to disable the register() call (like in that PR).

[trusktr]

In my use case, because Karma and it's configuration are located inside node_modules because my CLI tool uses Karma to run a project's tests, it complicates things: for example, the karma.config.js can't make an accurate guess as to which tsconfig.json file a project may be using, in order to extend it and disable allowJs and checkJs.

[johnjbarton]

(sorry for the duplicate)
Please add the breaking change info

https://www.conventionalcommits.org/en/v1.0.0/

and the doc change.

[muuvmuuv]

Can we please have this merged. It is blocking a PR in Angular builders that allows custom webpack configuration in Angular.

just-jeb/angular-builders#824

[mlegenhausen]

It seems the problem was fixed via 474f4e1. Now it should be possible to define a JS configuration that can call ts-node's register function without interfering with the karma register call.

I am currently unable to confirm if this solved the described problem cause I am not working anymore on any karma dependent project.