react-jsx | Compile transform your JSX templates

*Edited

My mistake was thinking that the webpack ts-loader would take context from from ts-config file and transpile the typescript according to that and webpack the content into the final bundle. Upon looking at my question again ive realised i put the index.tsx file as my entry point which is why i was still getting a bundled webpack file but my imports were undefined the only file being webpack was my index file i believe. That combined with the single file output tsc seems to have been the cause.

tsc was creating a bundle of my typescript.

webpack was creating a bundle of just my index.tsx file

Problem entry: './src/index.tsx' & "outFile": "./dist/main.js"

When using create-react-app, it is fine for my emotion theme types to go in:

Don't listen to past me, past me was 2 weeks into this problem and couldn't think straight. Felix Kling had it right, I needed the babel preset (@babel/preset-typescript) in my .babelrc.

The reason it seemed to freeze on Files successfully emitted, waiting for typecheck results... message is because the app was running and if I had checked my browser I would have seen the app. Something I did must have suppressed the warnings I usually see after this message.

I renamed my babel.config.js to .babelrc and added following code. It worked!

Check out this answer React Native Jest SyntaxError: Duplicate __self prop found

Also refer: https://reactjs.org/blog/2020/09/22/introducing-the-new-jsx-transform.html

Update @babel/core and @babel/plugin-transform-react-jsx

From docs:

tsc index.ts

emits JS for just the index.ts with the compiler defaults (not the project's tsconfig)

And, you can't specify file/s to compile and the tsconfig file on the CLI:

The biggest hint in that error is webpackEmptyContext. This isn't Node telling you that it failed to find @babel/preset-react" on the filesystem, it is Webpack telling you that it was unable to load @babel/preset-react" from it's bundle.

In the case of Babel, and anything with object-based config inputs, that is expected, because Webpack has no way to know that

Process.env.Something will always return String | undefined. There is no way for you to know for sure that that key will be in your environment.

You can try:

1. Yes, you are trying to install webpacker for this project once again when you're running rails webpacker:install on the CI machine.
2. Yes, what you need to run on another machine is rails assets:precompile. What it does it compiles all your assets for production, not development use and that's exactly what you'd want on the non-development machine (CI, staging, production).