Generic object literal completions include any random member you’re currently typing

[mjbvz]

From microsoft/vscode#85185

TypeScript Version: 3.8.0-dev.20191121

Search Terms:

• suggest / suggestions / completions / intellisense
• optional
• extends

Code
For the code:

interface Test {
    keyPath?: string;
    autoIncrement?: boolean;
}

function test<T extends Record<string, Test>>(opt: T) { }

test({
    a: {
        keyPath: '',
        a
    }
})

Trigger suggestions after a in the call to test.

Expected behavior:
Suggestion for autoIncrement returned.

Actual behavior:
No suggestion for autoIncrement. Only a single suggestion for a is returned

[Trace  - 18:58:01.966] <semantic> Sending request: completionEntryDetails (90). Response expected: yes. Current queue length: 0
Arguments: {
    "file": "/Users/matb/projects/san/a.ts",
    "line": 11,
    "offset": 10,
    "entryNames": [
        "a"
    ]
}

[RyanCavanaugh]

@andrewbranch I think you have a duplicate of this you've been looking at?

[andrewbranch]

This is mostly solved by #34855, except the bogus a completion is still there. I think @DanielRosenwasser told me we attempt to filter out object literal completions that are exactly what you’ve already typed, but I’ve noticed them come up basically all the time, so either that filtering is very broken or does not indeed exist.

I’ll keep this open until #34855 is merged and then will fix the superfluous completion afterwards or separately.