String enum computed values not allowed

[michaelgeorgeattard]

TypeScript Version: 2.7.0-dev.201xxxxx

Code

As mentioned earlier by @MadaraUchiha and others, why can we do the following?

const Foo = 0;

enum MyEnum {
    FooValue = Foo,
}

But not:

const Foo = "0";

enum MyEnum {
    FooValue = Foo,
}

It should be either both are valid, or none, this looks like an inconsistency in Typescript.

[mhegazy]

Should be addressed by #18887

[martabrzeszczyk]

@andy-ms Is it still going to be fixed? #18887 suggests that only conflicts needs to be resolved?

[pgraham]

#18887 was automatically closed due to inactivity, is this going to fixed?

[RyanCavanaugh]

This is disallowed on purpose.

String enums are syntactically differentiated from numeric enums by having string literals in all initialization positions. It's also the case that we need to produce a union type (instead of a branded primitive type) for a string literal enum, which aren't really sourced from consts without explicit type annotations.