Are spaces in enum keys allowed?

The following code

enum Foo {
  Bar = 1,
  ["Bar Test"] = 3,
}

compiles fine in TS Playground but inserting it into a clean create-react-app project produces a syntax error:

SyntaxError: <...>\ts-test\src\App.tsx: Unexpected token (7:2)

Is this valid TS? Is there some tsconfig variable or version that allows it?

Spaces are indeed allowed in enum keys; they are not required to be valid identifiers.

This doesn't seem to be explicitly documented anywhere obvious (the outdated spec section on enum declarations does indicate that the key could be any non-computed property name, which may be an identifier, but could also be a string literal).

However, there was a bug reported at microsoft/TypeScript#40152 and fixed at microsoft/TypeScript#40679 whereby enums with keys that were invalid as identifiers were causing the compiler to produce invalid JavaScript (presumably they had just assumed that keys would be valid identifiers). The fix was to change the emitted JavaScript to handle invalid identifier enum keys. That implies that enums with such keys are intentionally supported. Otherwise, the fix would be to make the TypeScript compiler reject such enum keys.

So it's safe to say that these are supported.