Support either type asserting `self` in classes, or properly ignoring workaround

I currently have a scenario very similar to https://github.com/microsoft/TypeScript/issues/2000#issuecomment-546929745. While it would be fixed it TS natively supported overriding class methods (see that issue), I followed the outline of the linked comment, but am running into a small issue. This is not a huge blocker but rather a nice-to have to get proper type completion for my scenario.

export class WritableObjStream<T> extends (stream.Writable as any) {
    writableObjectMode: true

    write(object: T, cb?: (error: Error | null | undefined) => void): boolean {
        return super.write(...more details)
    }
}

Because we type assert the base class to any, TS has no knowledge of the superclass. I tried a few solutions, with errors included below:

(super as any).write() // 'super' must be followed by an argument list or member access.

let s: stream.Writable = undefined;
// @ts-ignore
s = super // Identifier expected.

return s.write() // 'super' must be followed by an argument list or member access, Expected 1-3 arguments, but got 0.

Luckily, it autocomplete is picking up on the proper type of s.write() now and giving me an argument error.
Also, from what I can gather super is treated as a keyword not an identifier, which results in the error above.

This may not be the most common of errors, but there may be a few scenarios/other use cases. I tried writing a few examples up but none made real-world sense besides this use-case of a workaround for overriding methods.

Issue のクラス例と、回避策を説明しているリンク先の TypeScript issue/comment から始めます。このシナリオで TypeScript が super をどのようにパースし、型チェックするのかを調査し、そのうえで self の型アサーションをサポートすべきか、それとも回避策を明示的に拒否すべきかを判断します。示された例をカバーするテストによって、選択した動作が文書化されていれば完了です。