Set context of this keyword in definition file

Search Terms

set this context in typescript definition file

Suggestion

A way to change the context of this keyword in a type definition file. This is admittedly a weird feature since, to my knowledge, it doesn’t really align with how modules work. Perhaps there is another way to achieve this use case.

Use Cases

Here’s a video of how my application works - https://vimeo.com/315553984

I have an application that allows users to write code which will then be executed via the Function API - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function Here’s a simplified version of how the app works at its core -

const userCode = `
  console.log(this, foo, bar);
`;
const func = Function('foo', 'bar', userCode);
func.call({myThis: 'hello'}, 'fooString', 'barString');

My app allows users to write their code in Monaco editor and I’ve successfully added type definitions for the foo and bar variables via the addExtraLib method - https://microsoft.github.io/monaco-editor/api/interfaces/monaco.languages.typescript.languageservicedefaults.html

So when the user starts to type foo intellisense informs them that it is a string. I’d like to do the same for the this keyword.

Examples

See use cases ^

Checklist

My suggestion meets these guidelines:

• This wouldn’t be a breaking change in existing TypeScript/JavaScript code
• This wouldn’t change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn’t a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript’s Design Goals.

[clarkbynum]

Is there anyway TS knows what this is in the global scope? https://www.typescriptlang.org/play/#src=const thing %3D this%3B

If you hover over this in the above playground link it shows as any

[unional]

It feels like a Monaco editor issue. But I’m not 100% sure.