Test migration to jest by hand

Apparently using regular expressions is way easier.

test/sortedIndexBy/sortedIndexBy.js

@@ -0,0 +1,7 @@
+const sortedIndexBy = (arr, n, fn) => {
+const isDescending = fn(arr[0]) > fn(arr[arr.length - 1]);
+const val = fn(n);
+const index = arr.findIndex(el => (isDescending ? val >= fn(el) : val <= fn(el)));
+return index === -1 ? arr.length : index;
+};
+module.exports = sortedIndexBy;

test/sortedIndexBy/sortedIndexBy.test.js

@@ -0,0 +1,10 @@
+const expect = require('expect');
+const sortedIndexBy = require('./sortedIndexBy.js');
+
+
+  test('sortedIndexBy is a Function', () => {
+  expect(sortedIndexBy).toBeInstanceOf(Function);
+});
+  t.equal(sortedIndexBy([{ x: 4 }, { x: 5 }], { x: 4 }, o => o.x), 0, 'Returns the lowest index to insert the element without messing up the list order');
+  
+