map through enum

TypeScript Version: 3.1.6

Search Terms: enum

Code

enum ABC {
  A = 'A',
  B = 'B',
  C = 'C',
}
// No Error
for (const key in ABC) {
  console.log(ABC[key]);
}
// Error: Element implicitly has an 'any' type because index expression is not of type 'number'
Object.keys(ABC).map(key => console.log(ABC[key]));

Expected behavior:
Object.keys, values, entries on enum ABC infer type of ABC's key and value.
Actual behavior:
Cannot get inferred type.

Shouldn't type of key from enum be 'A' | 'B' | 'C'?

Start by reproducing the enum and Object.keys example from the issue with TypeScript 3.1.6, then compare the inferred types for the for-in and Object.keys cases. The work is done when Object.keys, values, and entries provide the expected enum key and value types without an implicit-any error.