[TS2.5 regression] Object.values(someEnum) returns string[] (not any[]/number[])

[mprobst]

TypeScript Version: 2.7.0-dev.201xxxxx

Code

enum X {A, B}

const xs = Object.values(X);
xs.includes(1);

Expected behavior:

In TS2.5, this used to compile, because xs was any[].

Actual behavior:

In TS2.6+, xs is string[]. That's wrong:

> Object.values({A: 1, B: 2})
[ 1, 2 ]

Related:

Curiously, this only happens for enums. {[k: ...}: V} style objects work fine.

const z: {[k: string]: number} = {
  A: 1
}
const zs = Object.values(z);
zs.includes(1);

[mhegazy]

The definition of values changed, and that seems to trigger this behaviour...

one option is to give enums a string indexer to string | number in addition to the number indexer, but I am not sure i understand what that would affect...

The other is to change definition of values, and use ArrayLike<T> instead of { [x: number] : T }. this seems like a smaller change.. I will give this a try.