TypeScript Version:

1.8

Code

// compiles
function foo(): number {
    throw new Error('Everything is gonna be alright!');
}

// does not compile
const bar: () => number = () => {
    throw new Error('WHYUNO?!?');
}

Expected behavior:
Functions foo and bar type-check, because an exception is thrown in their body which effectively means "bottom", so any return type should be permitted.

Actual behavior:
While function foo type-checks, bar does not.