Partial support decorators when targeting ES3 #4681
Description
Method/accessor decorators use defineProperty and getOwnPropertyDescriptor, which are not allowed in ES3. But class and property decorators don't use them. So class/property decorators can be allowed when targeting ES3.
It would be helpful. E.g. I must support old browsers and I use the property like methods instead of pure properties:
value(v?) {
if (arguments.length) {
// setter
} else {
// getter
}
}I have the factory function that creates such method:
interface Accessor<T> {
(): T;
(v: T): void;
}
function accessor<T>(propName: string): Accessor<T>;
function accessor<T>(propName: string) {
return function (v?: T) {
// if (arguments.length) and bla-bla-bla
}
}Currently I have to set such properties in the class prototype explicitly:
class Foo {
value: Accessor<string>;
}
Foo.prototype.value = accessor<string>("value");With decorators I could write more cleaner code:
function Accessor(proto, propName: string) {
proto[propName] = accessor(propName);
}
class Foo {
@Accessor
value: Accessor<string>;
}Also there is no need to duplicate the property name ("value" in the example above).