How to use generator function in typescript

Question

I am trying to use generator function in typescript. But the compiler throws error

error TS2339: Property 'next' does not exist on type

Below is an closest sample of my code.

export default class GeneratorClass {     constructor() {         this.generator(10);         this.generator.next();     }     *generator(count:number): Iterable<number | undefined> {         while(true)             yield count++;     }    } 

Here is the playground link for the same

Answer 1

The next method exists on the generator that the function returns, not on the generator function itself.

export default class GeneratorClass {     constructor() {         const iterator = this.generator(10);         iterator.next();     }     *generator(count:number): IterableIterator<number> {         while(true)             yield count++;     }    } 

Answer 2

I was seeing this error because my tsconfig.json was targeting es5.

I simply changed (excerpted) from:

"target": "es5", "lib": [     "es5",     "es2015.promise" ] 

to:

"target": "es6", "lib": [     "es6" ] 

and the error went away.

Note: For VS Code I needed to reload the window for IntelliSense to recognize the change.