A method of injecting javascript

A method of injection js

Many java framework to support apo injection, js can also be carried out to achieve a similar

Js mainly through the extension of the method of ancestors to implement a Function object.

Function.prototype.after = function(foo) {
    const thiz = this;
    return function(...args) {
         thiz.apply(thiz, args);
         foo.apply(thiz, args);

    }
}

//test
function test(param) {
    console.log("do");
}

function doAfter(param) {
    console.log("doAfter");
}

const doWithAfter = test.after(doAfter);