Implementation of interface requires members redeclaration - inside definition file

[CzBuCHi]

TypeScript Version: 2.3.2
Code:

// external_library.d.ts
interface A {
    foo: Function;
}
declare class B implements A { 
}

Expected behavior: no error
Actual behavior: error: Class 'B' incorrectly implements interface 'A'

This is sort of duplicate of #5749 or #340 except class is declared in d.ts file and implemented by javascript

Why: Currently is needed to copy all declarations from A into B... -> duplicate code

[RyanCavanaugh]

Not sure what makes this a not-exact-duplicate of #340. See #340 (comment)

[CzBuCHi]

@RyanCavanaugh sorry about that - i missed that comment ...