Erroneously implementing Interface doesn't throw an error

[Tarnadas]

interface SomeInterface {
  someMethodWhichShouldBeImplemented: () => void;
}

class SomeClass implements SomeInterface {
  // no implementation of 'someMethodWhichShouldBeImplemented' here
}

This code would still compile instead of throwing an error.

[dcodeIO]

Note that interfaces aren't implemented yet. In order to be able to annotate them already (i.e. when sharing code with TS) the compiler simply doesn't emit errors.

[andy-hanson]

This is also a problem with extends in templates:

interface HasX { x: i32 }
function f<T extends HasX>(x: T): i32 {
	return x.x;
}

class C { x: i32; }
class D { D: boolean; }

export function test(c: C, d: D): i32 {
	return f(c) + f(d);
}

There is a compile error, but it happens inside the body of the function rather than at the call site f(d) which could be confusing if you don't know which caller is the problem.

[dcodeIO]

Closing this issue as part of 2020 vacuum because seems to be outdated. Consider opening a new issue if necessary!