error TS2304: Cannot find name 'Generator'

Question

I updated typescript $ tsc -v Version 3.6.2

and tried the Generator example in the page below: https://devblogs.microsoft.com/typescript/announcing-typescript-3-6/

function* counter(): Generator<number, string, boolean> {
    let i = 0;
    while (true) {
        if (yield i++) {
            break;
        }
    }
    return "done!";
}

var iter = counter();
var curr = iter.next()
while (!curr.done) {
    console.log(curr.value);
    curr = iter.next(curr.value === 5)
}
console.log(curr.value.toUpperCase());

error TS2318: Cannot find global type 'IterableIterator'.

gen2.ts:6:22 - error TS2304: Cannot find name 'Generator'.

6 function* counter(): Generator { ~~~~~~~~~

Found 2 errors.

Vishal Vishal · Accepted Answer · 2019-09-05T22:05:08

In the tsconfig.json, update the "compilerOptions:target" value to ES2015 instead of ES5. Also, make sure to include your tsconfig.json in the CLI command like :

tsc -p .\tsconfig.json

error TS2304: Cannot find name 'Generator'

2 Answers