Compiled generators does not have correct constructor name

[paldepind]

TypeScript Version: 2.3.0-dev.20170407

function* myGeneratorFunction() {
    yield 1;
    return 2;
}

console.log(myGeneratorFunction.constructor.name);

Expected behavior:

Code logs "GeneratorFunction" when compiled to ES5.

Actual behavior:

Code logs "Function" when compiled to ES5.

Description:

Babel compiles this code so that the constructor name is set correctly. They do that by including a small run-time function that marks all generator functions as such. The source code for the marking function can be found here.

Compiling this per the specification is important since using the constructor name is the only way to check if a certain function is a generator function or not. See for instance this SO question and answer.

[KatSick]

Is there any updates ?

[paldepind]

@KatSick I am not aware of any updates. Previously it was tagged for the 2.4 release but now it's just tagged as future. I still really hope it'll be fixed as it's quite problematic for a project I'm working on.

@rbuckton is assigned to this issue. Do you have any idea about a timeline for this?

[nickbreaton]

This also applies to async functions:

TypeScript:

async function a() {}

a.constructor.name // "Function"

Latest version of Chrome:

async function a() {}

a.constructor.name // "AsyncFunction"

[rotu]

I think this is resolved.

[RyanCavanaugh]

This doesn't seem like an important scenario for modern JS development - folks can either target ES6 which is supported basically everywhere, or use an alternate transpiler with stricter adherence semantics if this is important for their scenario.