test(reverse): add tests for reverse() method

test/reverse/error.test.js

@@ -0,0 +1,16 @@
+'use strict';
+
+const test = require('ava');
+
+const reverse = require('../../lib/reverse');
+const createIterator = require('../../lib/create-iterator');
+
+test('should throw error if specified two arguments', t => {
+    const iter1 = createIterator([1, 2, 3]);
+    const iter2 = createIterator([4, 5, 6]);
+
+    t.throws(
+        () => reverse(iter1, iter2),
+        'The `resolve()` method not support more than one argument. Use `series() or `evenly()` to combine iterators.'
+    );
+});

test/reverse/iterator.test.js

@@ -0,0 +1,36 @@
+'use strict';
+
+const test = require('ava');
+
+const reverse = require('../../lib/reverse');
+const createIterator = require('../../lib/create-iterator');
+
+test('should return empty iterator', t => {
+    const iter = reverse();
+
+    t.deepEqual(iter.next(), { done: true });
+});
+
+test('should support empty iterator', t => {
+    const emptyIter = createIterator();
+
+    const iter = reverse(emptyIter);
+
+    t.deepEqual(iter.next(), { done: true });
+});
+
+test('should reverse iterator', t => {
+    const iter = createIterator([1, 2]);
+
+    const reverseIter = reverse(iter);
+
+    t.deepEqual(Array.from(reverseIter), [2, 1]);
+});
+
+test('should support iterable', t => {
+    const iterable = [1, 2];
+
+    const reverseIter = reverse(iterable);
+
+    t.deepEqual(Array.from(reverseIter), [2, 1]);
+});

test/reverse/values.test.js

@@ -0,0 +1,27 @@
+'use strict';
+
+const test = require('ava');
+
+const reverse = require('../../lib/reverse');
+
+test('should throw error if value is `null`', t => {
+    t.throws(() => reverse(null));
+});
+
+test('should throw error if value is `undefined`', t => {
+    t.throws(() => reverse(undefined));
+});
+
+test('should throw error if value is number', t => {
+    t.throws(() => reverse(123));
+});
+
+test('should throw error if value is boolean', t => {
+    t.throws(() => reverse(true));
+});
+
+test('should reverse string characters', t => {
+    const iter = reverse('str');
+
+    t.deepEqual(Array.from(iter), ['r', 't', 's']);
+});