Specify a custom tsconfig for indexTransform & customWebpackConfig

[GerkinDev]

Is your feature request related to a problem? Please describe.

I have a project with SSR & heavy custom tooling. My tooling takes the form of a custom CLI wrapper. This wrapper is written in typescript.

In order to reduce the number of warnings related to files part of typescript compilation but unused, I'd like to have an entirely different tsconfig for my tooling, webpack configs & the custom index transform.

Describe the solution you'd like

A new option allowing to specify a build-tsconfig (as opposed to an application-tsconfig) would just fit. I thought at first that a property in customWebpackConfig would do the job, but since this tsconfig would also apply to indexTransform, maybe it should be placed at the root of the options object of my target.

Describe alternatives you've considered

I've ended up including my webpack configs in my browser & server tsconfigs, which still cause the warnings, and isn't really relevant, but works.

Additional context

I can try to PR

[just-jeb]

Both customWebpackConfing.ts and indexTransform.ts are loaded with ts-node using tsconfig.app.json as a configuration file.
There is an option to configure specifically ts-node in tsconfig.json. I believe this should allow you to continue using tsconfig.app.json for your app compilation and ts-node specific section inside it for custom webpack and index transforms.

LMK if that helps.