add support for Jest's moduleNameMapper configuration

[nareshbhatia]

Allow merging of external moduleNameMapper configuration with the internal configuration required by react-scripts.

Fixes #4262

[facebook-github-bot]

Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. In order for us to review and merge your code, please sign up at https://code.facebook.com/cla. If you are contributing on behalf of someone else (eg your employer), the individual CLA may not be sufficient and your employer may need the corporate CLA signed.

If you have received this in error or have any questions, please contact us at [email protected]. Thanks!

[facebook-github-bot]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Facebook open source project. Thanks!

[nareshbhatia]

@iansu, just curious, what are the next steps to approving and merging this PR?

[nareshbhatia]

Requesting an update on this PR. This is the only critical issue that is preventing my company to move from create-react-app-ts to CRA.

TIA

[cubabit]

Looking forward to this getting merged and released!

[mrmckeb]

@nareshbhatia I'm discussing this with @iansu - we have been hard at work at 3.0, and then I think we can take a look at this for you.

[nareshbhatia]

Thanks for the update, @mrmckeb. Waiting eagerly :-)

[ponciusz]

any progress with that??

[nareshbhatia]

As far as I can tell, this change has been implemented in code. If yes, this PR can be closed.

Note that the docs are still out-of-sync, moduleNameMapper is not included as a supported tag.

[ianschmitz]

Already fixed by #6055.