Anonymous/inline interface implementation in TypeScript

OK, I finally discovered the problem to question 2 – I was using the fat arrow => to declare the object’s method here:

doThatThing(<Doable>{ 
    private message: 'ahoy-hoy!', 
    do: () => { // using fat arrow: global scope replaces new object's scope
        alert(this.message);
    }
});

…which “sucked” the global scope into the method. The problem is fixed using the longer syntax, like so:

doThatThing(<Doable>{
    private message: 'ahoy-hoy!',
    do: function() { // using "regular" anonymous function syntax, "this" meaning is preserved
        alert(this.message);
    }
});

So in summary:

1. unanswered;
2. There was a typo in my code, and I should have been using “function()” instead of “=>”; and,
3. Type-asserting the object with the interface removes the compiler error.