Fold And in ECMAScript2015 with babel, mocha, expect.js, and lodash

foldAnd.js

let _ = require("lodash");

exports.foldAnd = (...facts) =>
	_.foldl(facts, (m, x) => m && x, true);

foldAndSpec.js

let sut = require("../src/foldAnd"),
	expect = require("expect.js"),
	_ = require("lodash");

describe("foldAnd", () => {
	it("Given all true it must return true", () => {
		expect(sut.foldAnd(true)).to.be.ok();
		expect(sut.foldAnd(true, true)).to.be.ok();
		expect(sut.foldAnd(true, true, true)).to.be.ok();
	}),
	it("Given all false it must return false", () => {
		expect(sut.foldAnd(false)).not.to.be.ok();
		expect(sut.foldAnd(false, false)).not.to.be.ok();
		expect(sut.foldAnd(false, false, false)).not.to.be.ok();
	}),
	it("Given some true and false it must return the same result as every", () => {
		expect(sut.foldAnd(true, false)).to.equal(_.every([true, false]));
		expect(sut.foldAnd(false, true)).to.equal(_.every([false, true]));
		expect(sut.foldAnd(false, true, false)).to.equal(_.every([false, true, false]));
		expect(sut.foldAnd(false, false, true)).to.equal(_.every([false, false, true]));
	})
});

Based on http://www.cs.nott.ac.uk/~gmh/fold.pdf

See also my blog post which goes with this gist http://comp-phil.blogspot.com/2015/08/approaching-fold.html