Typescript @trace annotation

trace.ts

class Dog {
    @trace
    compute(a: number, b: number): any {
        // my dog is a bit slow and weird to compute..
        for (var i = 0; i < 1000000000; i++) {
            var result = a + b;
        }

        // .. not even accurate
        return 'wouf';
    }
}

function trace(instance, name, descriptor) {
    var original = descriptor.value;

    descriptor.value = function() {
        var traceName = instance.constructor.name + '.' + name;

        console.time(traceName);

        var result = original.apply(instance, arguments);

        console.timeEnd(traceName);

        return result;
    }

    return descriptor;
}

// create my dog
var d = new Dog();

console.log(d.compute(10, 12));