fix(49546): 'Add missing properties' quick fix incorrectly handles symbol property

[a-tarasyuk]

Fixes #49546

[RyanCavanaugh]

@typescript-bot pack this

[typescript-bot]

Heya @RyanCavanaugh, I've started to run the tarball bundle task on this PR at 1d34960. You can monitor the build here.

[typescript-bot]

Hey @RyanCavanaugh, I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/128212/artifacts?artifactName=tgz&fileId=D7F4F2303C5D667F727C1A1CA535BDF5BC882B8B64A693C5C252B62AEC164D1702&fileName=/typescript-4.8.0-insiders.20220615.tgz"
    }
}

and then running npm install.

---

There is also a playground for this build and an npm module you can use via "typescript": "npm:@typescript-deploys/pr-build@4.8.0-pr-49554-2".;

[RyanCavanaugh]

This is better than the current behavior but still defeatable

const m: unique symbol = Symbol();
interface T {
    [m]: string;
}
function fn(m: any) {
    let p: T = {
    //  ^ fix here tries to reference shadowed 'm'
    };
}

Is it more practical to disable the add missing members fix when the keys aren't literal-named?

[a-tarasyuk]

const m: unique symbol = Symbol();
interface T {
   [m]: string;
   a: number;
   b: string;
}
[|let p: T = {};|]

@RyanCavanaugh If the type contains at least one computed property, QF should not be suggested. Am I right?

[RyanCavanaugh]

I'm sort of on the fence, let me think about it more

[a-tarasyuk]

@RyanCavanaugh I'm not sure what is the right way to resolve this edge case with naming collisions. We can skip computed properties and implement only known keys. Or we can try to find all the names in the current scope and try to rename something (not sure which name to rename) / or mark it as "unknown" key. Or completely skip QF. I think it depends on how often this case occurs.

[RyanCavanaugh]

Eh, this seems unlikely to break in practice. Let's see how it goes.