Updated the test system

test/composeRight.test.js

@@ -0,0 +1,12 @@
+const expect = require('expect');
+const {composeRight} = require('./_30s.js');
+
+test('composeRight is a Function', () => {
+  expect(composeRight).toBeInstanceOf(Function);
+});
+const add = (x, y) => x + y;
+const square = x => x * x;
+const addAndSquare = composeRight(add, square);
+test('Performs left-to-right function composition', () => {
+  expect(addAndSquare(1, 2)).toBe(9);
+});