🐒 Chainable forEach monkey patch !

jojoChainableForEach.js

(function(oldForEach) {
  Array.prototype.forEach = function() {
    oldForEach.apply(this, arguments);
    return this;
  };
}(Array.prototype.forEach));

[1, 2, 3]
  .forEach(item => console.log(1, item))
  .forEach(item => console.log(2, item))

// 1 1
// 1 2
// 1 3
// 2 1
// 2 2
// 2 3

describe('forEach', () => {

    const testData = [10, 9, 8, 7, 6, 5, 4, 3, 2, 1];

    describe('oldForEach', () => {
        it('should not return anything', () => {
            const result = testData.forEach((item) => { testData.should.containEql(item); });
            should.not.exist(result);
        });
    });

    describe('newForEach', () => {
        it('should return the origina list', () => {

            require('./jojoChainable');

            const result = testData.forEach((item) => { testData.should.containEql(item); });
            should.exist(result);
            result.should.be.exactly(testData);
        });
    });

});

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