decorators example

gistfile1.txt

// code

const foo = function(target) {
    target.prototype.foo = function() {
        console.log("foo");
    }
}

const bar = function(myText) {
    return function(target) {
        target.prototype.bar = function() {
            console.log(myText);
        }
    }
}

const readonly = (target, key, descriptor) => {
    descriptor.writable = false;
}

const deprecated = (target, key, descriptor) => {
    const old = descriptor.value;
    descriptor.value = () => {
        console.log('deprecated');
        old();
    }
}
// Object.defineProperty(target, key, descriptor)

@foo
@bar('BAR')
class MyClass {
    constructor() {
        this.foo();
        this.bar();
        this.myMethod();
        this.myProp = '456';
    }

    @readonly
    myProp = '123';

    @deprecated
    myMethod() {
        console.log('this should not happen');
    }
}


new MyClass()


// .babelrc
{
    "presets": ["env"],
    "plugins": ["transform-decorators-legacy", "transform-class-properties"]
}