Add tests for InlineKeyboardButton.

tests/Unit/Entities/InlineKeyboardButtonTest.php

+<?php
+/**
+ * This file is part of the TelegramBot package.
+ *
+ * (c) Avtandil Kikabidze aka LONGMAN <akalongman@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Tests\Unit;
+
+use Longman\TelegramBot\Entities\InlineKeyboardButton;
+use Longman\TelegramBot\Exception\TelegramException;
+
+/**
+ * @package         TelegramTest
+ * @author          Avtandil Kikabidze <akalongman@gmail.com>
+ * @copyright       Avtandil Kikabidze <akalongman@gmail.com>
+ * @license         http://opensource.org/licenses/mit-license.php  The MIT License (MIT)
+ * @link            http://www.github.com/akalongman/php-telegram-bot
+ */
+class InlineKeyboardButtonTest extends TestCase
+{
+    /**
+     * @expectedException \Longman\TelegramBot\Exception\TelegramException
+     * @expectedExceptionMessage text is empty!
+     */
+    public function testInlineKeyboardButtonNoTextFail()
+    {
+        new InlineKeyboardButton([]);
+    }
+
+    /**
+     * @expectedException \Longman\TelegramBot\Exception\TelegramException
+     * @expectedExceptionMessage You must use only one of these fields: url, callback_data, switch_inline_query!
+     */
+    public function testInlineKeyboardButtonNoParameterFail()
+    {
+        new InlineKeyboardButton(['text' => 'message']);
+    }
+
+    /**
+     * @expectedException \Longman\TelegramBot\Exception\TelegramException
+     * @expectedExceptionMessage You must use only one of these fields: url, callback_data, switch_inline_query!
+     */
+    public function testInlineKeyboardButtonTooManyParametersFail()
+    {
+        new InlineKeyboardButton(['text' => 'message', 'url' => 'url_value', 'callback_data' => 'callback_data_value']);
+    }
+
+    public function testInlineKeyboardButtonSuccess()
+    {
+        new InlineKeyboardButton(['text' => 'message', 'url' => 'url_value']);
+        new InlineKeyboardButton(['text' => 'message', 'callback_data' => 'callback_data_value']);
+        new InlineKeyboardButton(['text' => 'message', 'switch_inline_query' => 'switch_inline_query_value']);
+    }
+}