Narrowing a return type from a generic, discriminated union in TypeScript

Question

I have a class method which accepts a single argument as a string and returns an object which has the matching type property. This method is used to narrow a di

Answer 1

Unfortunately, you cannot achieve this behavior using union type (ie type MyActions = ExampleAction | AnotherAction;).

If we have a value that has a union type, we can only access members that are common to all types in the union.

However, your solution is great. You just have to use this way to define the type you need.

const result2 = items.doSomething('Example');

Although you don't like it, it seems pretty legit way to do what you want.