Fail to import `classPrivateFieldGet` from tslib when `"importHelpers": true`

[millsp]

I am testing out the lastest ECMA private fields. I get an error when importHelpers enabled:

This syntax requires an imported helper named '__classPrivateFieldGet' which does not exist in 'tslib'. Consider upgrading your version of 'tslib'.ts(2343)

I'm not sure if there's pending work on the tslib, so I'm repoting this anyway.

TypeScript Version: 3.8.1-rc
TS Lib Version: 1.1.0

Search Terms:
tslib classPrivateFieldGet

Code

class A {
    #a: number

    constructor() {
        this.#a = 1
    }
}

Expected behavior:

This should compile

Actual behavior:

Shows an error on tslib

Playground Link:

Related Issues:

[Haringat]

I have a few additional observations:

1. When I only compile one file typescript seems to completely ignore the importHelpers: true option and emit all required helpers (including __classPrivateFieldGet and __classPrivateFieldSet) into the js file. When the compiled file references other files via imports the behaviour @pirix-gh described occurres.
2. When module: "CommonJS" is set, it imports all helpers just as you would expect. However, when module: "ESNext" or "module: "ES2015" it does not import __classPrivateFieldGet and __classPrivateFieldSet (other helpers like __awaiter are imported though)

[motss]

I believe that this is a bug as the helpers for setting and getting private fields will be imported only when module set to CommonJS.

[dev-johnny-gh]

i have another question. ts transplie #property to weakmap(this) to store the property value.

while the class instance destroyed and recycled by the gc, the property value of this class instance still store in weakmap.

will it cause a memory leak?

[dev-johnny-gh]

well, reply to myself, it seems chrome will clean up all values in weakmap after their key have been gc'ed

[Haringat]

@duxiaofeng-github Not just chome, but v8 in general and all other javascript engines too. It is a part of the specification as you can read here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakMap

[dev-johnny-gh]

@Haringat thx, i read that doc before, i must miss something...

[cedx]

Same issue here with typescript 3.8.3 and tslib 1.11.1.