livid wharf
CC: @vocal hornet
I have an object which is a plain record type (it must be a plain record type, since it is the result of parsing a user-supplied plain-text file). However, there are some keys that, when checked and accessed, should be one type instead of another. For example:
type MyRecord = {
[string]?: string,
['Foo' | 'Bar' | 'Baz']?: string[],
};
const x: MyRecord = someFunc();
if (x['Test']) // any key is a string, if defined:
console.log(x['Test'].toUpperCase());
if (x['Foo']) // any of the specific keys make it an array:
console.log(x['Foo'].map(s => s.toUpperCase());
Might be worth noting that the union is coming from an ['...', '...'] as const.
