Enhance BaseServices testing

Author: jim-parry

system/Config/BaseService.php

@@ -184,7 +184,7 @@ public static function __callStatic(string $name, array $arguments)
 	{
 		$name = strtolower($name);
 
-		if (method_exists(__CLASS__, $name))
+		if (method_exists(Services::class, $name))
 		{
 			return Services::$name(...$arguments);
 		}

tests/system/Config/ServicesTest.php

@@ -1,4 +1,7 @@
-<?php namespace Config;
+<?php
+namespace Config;
+
+use Tests\Support\HTTP\MockResponse;
 
 class ServicesTest extends \CIUnitTestCase
 {
@@ -227,4 +230,51 @@ public function testCallStatic()
 		$this->assertInstanceOf(\CodeIgniter\Session\Session::class, $actual);
 	}
 
+	/**
+	 * @runInSeparateProcess
+	 * @preserveGlobalState  disabled
+	 */
+	public function testCallStaticDirectly()
+	{
+		//      $actual = \CodeIgniter\Config\Services::SeSsIoN(null, false); // original
+		$actual = \CodeIgniter\Config\Services::__callStatic('SeSsIoN', [null, false]);
+		$this->assertInstanceOf(\CodeIgniter\Session\Session::class, $actual);
+	}
+
+	/**
+	 * @runInSeparateProcess
+	 * @preserveGlobalState  disabled
+	 */
+	public function testMockInjection()
+	{
+		Services::injectMock('response', new MockResponse(new App()));
+		$response = service('response');
+		$this->assertInstanceOf(MockResponse::class, $response);
+
+		Services::injectMock('response', new MockResponse(new App()));
+		$response2 = service('response');
+		$this->assertInstanceOf(MockResponse::class, $response2);
+
+		$this->assertEquals($response, $response2);
+	}
+
+	/**
+	 * @runInSeparateProcess
+	 * @preserveGlobalState  disabled
+	 */
+	public function testReset()
+	{
+		Services::injectMock('response', new MockResponse(new App()));
+		$response = service('response');
+		$this->assertInstanceOf(MockResponse::class, $response);
+
+		Services::reset(true); // reset mocks & shared instances
+
+		Services::injectMock('response', new MockResponse(new App()));
+		$response2 = service('response');
+		$this->assertInstanceOf(MockResponse::class, $response2);
+
+		$this->assertTrue($response !== $response2);
+	}
+
 }