No contextual typing for interfaces that extends interface with index signature

[tinganho]

I was hoping this could work:

class A {
    public a: string;
}

interface B {
    [index: string]: A;
}

interface C extends B {
    a;
    b;
    c;
}

let c: C;
c.a.a // c.a of type A

but members of interface C has type any instead I was hoping I could get type A?

Notice I don't want to define directly:

let c: B;

because I need to pass C as a type with defined props.

[RyanCavanaugh]

Contextual typing applies to expressions, not declarations, so that part isn't exactly relevant.

It's legal to declare members of type any (which is what you've done) even when you have an index signature. I don't think we would take a breaking change here.

[tinganho]

This is my problem right now:

interface StyleRules extends Radium.StyleRules {
    feed: Radium.CSSStyleDeclaration;
    feedTitle: Radium.CSSStyleDeclaration;
    feedLoadMoreButton: Radium.CSSStyleDeclaration;
.   ...
}

Having to repeat a type that I think could be inferred from a base interface. If not inferred maybe be able to reference the base signature value type?

[RyanCavanaugh]

#1373 ?

[tinganho]

Yes sort of related. Though this suggestion is an interface derived from an
interface/class. His suggestion where a class derived from a
interface/class.

tis 14 juli 2015 kl 00:45 skrev Ryan Cavanaugh notifications@github.com:

#1373 #1373 ?

—
Reply to this email directly or view it on GitHub
#3804 (comment)
.