Updated the test system

test/bifurcateBy.test.js

@@ -0,0 +1,12 @@
+const expect = require('expect');
+const {bifurcateBy} = require('./_30s.js');
+
+test('bifurcateBy is a Function', () => {
+  expect(bifurcateBy).toBeInstanceOf(Function);
+});
+test('Splits the collection into two groups', () => {
+  expect(bifurcateBy(['beep', 'boop', 'foo', 'bar'], x => x[0] === 'b')).toEqual([
+    ['beep', 'boop', 'bar'],
+    ['foo']
+  ]);
+});