wip: code formatting nits continued

test/nth.spec.js

@@ -0,0 +1,58 @@
+import lodashStable from 'lodash';
+import { falsey, stubA, stubB, noop } from './utils';
+import nth from '../src/nth';
+
+describe('nth', () => {
+    const array = ['a', 'b', 'c', 'd'];
+
+    it('should get the nth element of `array`', () => {
+        const actual = lodashStable.map(array, (value, index) => nth(array, index));
+
+        expect(actual).toEqual(array);
+    });
+
+    it('should work with a negative `n`', () => {
+        const actual = lodashStable.map(lodashStable.range(1, array.length + 1), (n) =>
+            nth(array, -n),
+        );
+
+        expect(actual, ['d', 'c', 'b').toEqual('a']);
+    });
+
+    it('should coerce `n` to an integer', () => {
+        let values = falsey;
+        let expected = lodashStable.map(values, stubA);
+
+        let actual = lodashStable.map(values, (n) => (n ? nth(array, n) : nth(array)));
+
+        expect(actual).toEqual(expected);
+
+        values = ['1', 1.6];
+        expected = lodashStable.map(values, stubB);
+
+        actual = lodashStable.map(values, (n) => nth(array, n));
+
+        expect(actual).toEqual(expected);
+    });
+
+    it('should return `undefined` for empty arrays', () => {
+        const values = [null, undefined, []];
+        const expected = lodashStable.map(values, noop);
+
+        const actual = lodashStable.map(values, (array) => nth(array, 1));
+
+        expect(actual).toEqual(expected);
+    });
+
+    it('should return `undefined` for non-indexes', () => {
+        const array = [1, 2];
+        const values = [Infinity, array.length];
+        const expected = lodashStable.map(values, noop);
+
+        array[-1] = 3;
+
+        const actual = lodashStable.map(values, (n) => nth(array, n));
+
+        expect(actual).toEqual(expected);
+    });
+});