[typescript] Generic parameter is not removed when using the optional chaining operator

[RafaelSalguero]

Bug Report

• [ X ] I would like to work on a fix!

Current behavior
Generic parameters are not removed from function calls after using the optional chaining operator

• Codesandbox, Repo
  Input Code

//ok:
let x: number[] = [1,2,3];
x.map<boolean>(x => x > 1);

//error (generic parameter not removed):
let y: number[] = [1,2,3];
y?.map<boolean>(x => x > 1);

Expected behavior
Generic parameters should be removed from function calls after the optional chaining operator

Babel Configuration (babel.config.js, .babelrc, package.json#babel, cli command, .eslintrc)

• Filename: babel.config.json

{
  "presets": [
    [
      "@babel/preset-typescript",
      {
        "isTSX": true,
        "allExtensions": true
      }
    ]
  ]
}

Environment

  System:
    OS: Windows 10 10.0.19041
  Binaries:
    Node: 12.18.0 - C:\Program Files\nodejs\node.EXE
    npm: 6.14.4 - C:\Program Files\nodejs\npm.CMD   
  npmPackages:
    @babel/cli: ^7.10.4 => 7.10.4
    @babel/core: ^7.10.4 => 7.10.4
    @babel/preset-typescript: ^7.10.4 => 7.10.4    

• Monorepo: no
• How you are using Babel: cli

[babel-bot]

Hey @RafaelSalguero! 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."

[JLHwung]

x?.map<boolean>() is an OptionalCallExpression, we shall remove its typeParameters like we did for CallExpression

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

Lines 418 to 420 in 55ce749

	CallExpression(path) {
	path.node.typeParameters = null;
	},

@RafaelSalguero If you are willing to send a PR, please leave a message so I will assign this issue to you, thanks.

If you don't know how to clone 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 make bootstrap
5. Wait ⏳
6. Run make watch (or make build whenever you change a file)
7. Add a test (only input.js; output.js will be automatically generated) to packages/babel-plugin-transform-typescript/test/fixtures/type-arguments
8. Update the code!
9. 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
10. If it is working, run make test to run all the tests
11. Run git push and open a PR!

[RafaelSalguero]

@JLHwung please assign the issue to me, thanks!