Make TypeScript basePath configurable, fixes #619

[loilo]

Enables the behaviour suggested in #619 to modify the basePath provided to the TS compiler.

Added:

• Implementation
• Comparison test
• Hint in README

[johnnyreilly]

Great! I'll look to include this in the next release. Thanks!

[johnnyreilly]

Released with https://github.com/TypeStrong/ts-loader/releases/tag/v2.3.5

[pettyalex]

This seems to break the default tsconfig.json as distributed with create-react-app-typescript.

I'm seeing failures with

TS6059: File '/app/src/App.test.tsx' is not under 'rootDir' '/app/src/src'. 'rootDir' is expected to contain all source files.�

[pettyalex]

The quick and dirty workaround is to change rootDir to '.' rather than 'src', but I'm not sure whether create react app's tsconfig is wrong, or some other part of the build pipeline is causing the issue.

I should really give more info, the default project structure with create-react-app-typescript has tsconfig in the project base path, and src contains all source files, but with this latest change the typescript compiler is looking in src/src for some reason.

[loilo]

That's weird. As far as I can tell, the provided basePath should be correct (it does not contain src/src, just a single src).

I'm probably going to have to look into how exactly TypeScript handles the basePath, this smells like some errornous assumptions from my side.

[johnnyreilly]

If you could look into this I'd appreciate that @loilo. @pettyalex let's see what @loilo comes up with. If all else fails we can revert this change and push out a new version. For now I would pin your version to 2.3.4 though.

[loilo]

I think that's currently the best solution. I created a quick repro repo where I couldn't nail it down yet, gonna get to work now but going to look at the problem from there. I suggest to move every further communication over to wmonk/create-react-app-typescript#156.