Updated the test system

test/converge.test.js

@@ -0,0 +1,17 @@
+const expect = require('expect');
+const {converge} = require('./_30s.js');
+
+test('converge is a Function', () => {
+  expect(converge).toBeInstanceOf(Function);
+});
+const average = converge((a, b) => a / b, [
+  arr => arr.reduce((a, v) => a + v, 0),
+  arr => arr.length
+]);
+test('Produces the average of the array', () => {
+  expect(average([1, 2, 3, 4, 5, 6, 7])).toBe(4);
+});
+const strangeConcat = converge((a, b) => a + b, [x => x.toUpperCase(), x => x.toLowerCase()]);
+test('Produces the strange concatenation', () => {
+  expect(strangeConcat('Yodel')).toBe('YODELyodel');
+});