Babel error when using override of TypeScript 4.3.2

[Lonest90]

What version of Next.js are you using?

11.0.1

What version of Node.js are you using?

14.16.0

What browser are you using?

Chrome

What operating system are you using?

Windows

How are you deploying your application?

next dev

Describe the Bug

I noticed that the basic-feature of docs has the wrong information as it says:

It is highly recommended to be on at least v4.3.2 of TypeScript to experience the best performance when leveraging this feature.

But Next.JS still doesn't support some features of the version because of the Babel version 7.12.5, and what's new in TypeScript 4.3 is only added in version 7.14.0 as per the update notes

Uncaught at getBabelError

Expected Behavior

update the Babel dependency of Next.JS to version 7.14.0, or remove the Incremental type checking from the docs telling to use a TypeScript version that Next.JS is not yet supported.

To Reproduce

an example error is using the new TypeScript override:

class Test {
  show () {
    console.log('show Test')
  }
}

class Test2 extends Test {
  override show(){
    console.log('overriding show Test')
  }
}

new Test2().show()

[cakoose]

I ran into this as well. Is there a way to set the Babel dependency version in package.json (I'm using yarn) to make this work?

[feRpicoral]

I'm having the same issue. Tried installing @babel/preset-typescript separately but it didn't work as well.

[ijjk]

Hi, this should be fixed in the latest canary of Next.js v11.1.1-canary.10, please update and give it a try!

[Lonest90]

Hi @ijjk, I tested it and it's working, thanks.

[balazsorban44]

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