Test migration to jest by hand

Apparently using regular expressions is way easier.

test/reduceWhich/reduceWhich.js

@@ -0,0 +1,3 @@
+const reduceWhich = (arr, comparator = (a, b) => a - b) =>
+arr.reduce((a, b) => (comparator(a, b) >= 0 ? b : a));
+module.exports = reduceWhich;

test/reduceWhich/reduceWhich.test.js

@@ -0,0 +1,15 @@
+const expect = require('expect');
+const reduceWhich = require('./reduceWhich.js');
+
+
+  test('reduceWhich is a Function', () => {
+  expect(reduceWhich).toBeInstanceOf(Function);
+});
+  t.equal(reduceWhich([1, 3, 2]), 1, 'Returns the minimum of an array');
+  t.equal(reduceWhich([1, 3, 2], (a, b) => b - a), 3, 'Returns the maximum of an array');
+  t.deepEqual(reduceWhich(
+  [{ name: 'Tom', age: 12 }, { name: 'Jack', age: 18 }, { name: 'Lucy', age: 9 }],
+  (a, b) => a.age - b.age
+), {name: "Lucy", age: 9}, 'Returns the object with the minimum specified value in an array');
+  
+