From: microsoft/vscode#25363

TypeScript Version: 2.3.1

Code

type Z = { abc: number, xyz: string }

function foo<T>(z: keyof T) { }

foo<Z>('')

Trigger suggestions inside of the quotes in the function call.

Expected behavior:
Returns suggestions for abc and xyz

Actual behavior:
No suggestions returned in this case.

If a non-generic type is used:

type Z = { abc: number, xyz: string }

function foo(z: keyof Z) { }

foo('')

Then suggestions are returned