Add unit tests for Bot class

tests/TgBotLib/BotTest.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace TgBotLib;
+
+use PHPUnit\Framework\TestCase;
+
+class BotTest extends TestCase
+{
+    private $bot;
+    protected function setUp(): void
+    {
+        $this->bot = new Bot(BOT_TOKEN);
+    }
+
+    /**
+     * Test sendRequest method of Bot class
+     * for valid method and parameters.
+     */
+    public function testSendRequestValid(): void
+    {
+        $method = 'getMe';
+        $parameters = ['text' => 'test message'];
+
+        // assuming that sendMessage method is properly working
+        $result = $this->bot->sendRequest($method, $parameters);
+
+        $this->assertIsArray($result);
+    }
+
+    /**
+     * Test sendRequest method of Bot class
+     * for invalid method.
+     */
+    public function testSendRequestInvalidMethod(): void
+    {
+        $method = 'invalidMethod';
+        $parameters = [];
+
+        $this->expectException(InvalidArgumentException::class);
+
+        $this->bot->sendRequest($method, $parameters);
+    }
+}