TypeScript 5.2 features

[nicolo-ribaudo]

💻

• Would you like to work on this feature?

What problem are you trying to solve?

We need to make sure we support all the TS 5.2 features: https://devblogs.microsoft.com/typescript/announcing-typescript-5-2/

The missing ones are:

• Decorators metadata ([Bug]: Decorator metadata is not implemented #15889) - I'm working on this
• Named and Anonymous Tuple Elements: [first: T, T] is now a valid type - good first issue :) (Allow TS tuples to have both labeled and unlabeled elements #15896)

Everything else seems to be supported

Describe the solution you'd like

/

Describe alternatives you've considered

/

Documentation, Adoption, Migration Strategy

No response

[nicolo-ribaudo]

Named and Anonymous Tuple Elements: [first: T, T] is now a valid type

For this change, we just need to delete the error about mixing tuple elements with and without labels from our parser. Tuples parsing is implemented at

babel/packages/babel-parser/src/plugins/typescript/index.ts

Line 1041 in e43d8e7

tsParseTupleType(): N.TsTupleType {

.

Then, there will probably be some tests that can be deleted because they were testing that error.

---

If it is the first time that you contribute to Babel, follow these steps: (you need to have make and yarn available on your machine)

1. Write a comment there to let other possible contributors know that you are working on this bug.
2. Fork the repo
3. Run git clone https://github.com/<YOUR_USERNAME>/babel.git && cd babel
4. Run yarn && make bootstrap
5. Wait ⏳
6. Run make watch (or make build whenever you change a file)
7. Add a test (only input.ts; output.json will be automatically generated)
8. Update the code!
9. yarn jest babel-parser to run the tests
   • If some test outputs don't match but the new results are correct, you can delete the bad output.js files and run the tests again
   • If you prefer, you can run OVERWRITE=true yarn jest babel-parser and they will be automatically updated.
10. If it is working, run make test to run all the tests
11. Run git push and open a PR!

[yukukotani]

I'm going to work on Named and Anonymous Tuple Elements

[ShiviTripathi13]

Is this issue still open, if yes, please assign it to me.

[liuxingbaoyu]

@ShiviTripathi13 Thank you! Now they have been completed. :)