Unbound type parameter error for interface extending type

[davidfurey]

When you extend a generic interface, typescript-is correctly identifies that you have bound the type parameter. If instead you extend a generic type alias, typescript-ts throws the error Unbound type parameter, missing type node.

Example with error

type Y<T> = {
    field: T;
}

interface X extends Y<string> { }

is<X>({ field: 'some-string' })

Example without error

interface Y<T> {
    field: T;
}

interface X extends Y<string> { }

is<X>({ field: 'some-string' })

[woutervh-]

Thanks again for the PR, @davidfurey

Release: https://github.com/woutervh-/typescript-is/releases/tag/v0.17.1