Updated the test system

test/overArgs.test.js

@@ -0,0 +1,12 @@
+const expect = require('expect');
+const {overArgs} = require('./_30s.js');
+
+test('overArgs is a Function', () => {
+  expect(overArgs).toBeInstanceOf(Function);
+});
+const square = n => n * n;
+const double = n => n * 2;
+const fn = overArgs((x, y) => [x, y], [square, double]);
+test('Invokes the provided function with its arguments transformed', () => {
+  expect(fn(9, 3)).toEqual([81, 6]);
+});