[Bug]: Missing registerDeclaration in plugin-transform-typescript

[amoeller]

💻

• Would you like to work on a fix?

How are you using Babel?

Programmatic API (babel.transform, babel.parse)

Input code

import foo = bar

Configuration file name

No response

Configuration

No response

Current and expected behavior

plugin-transform-typescript fails to register the declaration at

        path.replaceWith(
          t.variableDeclaration("var", [
            t.variableDeclarator(
              path.node.id,
              entityNameToExpr(path.node.moduleReference),
            ),
          ]),
        );

in packages/babel-plugin-transform-typescript/src/index.ts.

Environment

@babel/plugin-transform-typescript: 7.20.13

Possible solution

Insert

path.scope.registerDeclaration(path);

after this line:

babel/packages/babel-plugin-transform-typescript/src/index.ts

Line 594 in 6e8ce9d

);

Additional context

No response

[babel-bot]

Hey @amoeller! We really appreciate you taking the time to report an issue. The collaborators on this project attempt to help as many people as possible, but we're a limited number of volunteers, so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack community that typically always has someone willing to help. You can sign-up here for an invite.

[nicolo-ribaudo]

Thank you! I'm assigning this issue to you since you selected "Would you like to work on a fix?"

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. Fork the repo
2. Run git clone https://github.com/<YOUR_USERNAME>/babel.git && cd babel
3. Run yarn && make bootstrap
4. Wait ⏳
5. Run make watch (or make build whenever you change a file)
6. Add a test in https://github.com/babel/babel/tree/main/packages/babel-plugin-transform-typescript/test. Testing this is a bit hard, maybe we could create a test with a custom plugin.js (like https://github.com/babel/babel/tree/main/packages/babel-plugin-transform-typescript/test/fixtures/regression/10162) which logs all the registered declaration on Program:exit, and with the "validateLogs": true option enabled.
7. Update the code!
8. yarn jest transform-typescript 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 [name-of-the-package-to-test] and they will be automatically updated.
9. If it is working, run make test to run all the tests
10. Run git push and open a PR!

Feel free to ask here if you need any other help :)