Is it possible to force the typescript compiler check all possible branches when having a return type?

Question

I see that the typescript checker does not give a warning or an error when having a function like this:

function test(a: boolean): boolean {
    if (a) {
        return true;
    } else {
        // else branch not covered
    }
}

Is there a property that could be set in the tsconfig.json file to force the compiler to do the check? (I could not find any)

Answer 1

The noImplicitReturns flag should do exactly that:

https://www.typescriptlang.org/tsconfig#noImplicitReturns