Added EmailService

src/Services/EmailService.php

@@ -0,0 +1,14 @@
+<?php
+namespace Szurubooru\Services;
+
+class EmailService
+{
+	public function validateEmail($email)
+	{
+		if (!$email)
+			return;
+
+		if (!preg_match('/^[^@]+@[^@]+\.\w+$/', $email))
+			throw new \DomainException('Specified e-mail appears to be invalid.');
+	}
+}

tests/Services/EmailServiceTest.php

@@ -0,0 +1,28 @@
+<?php
+namespace Szurubooru\Tests\Services;
+
+class EmailServiceTest extends \PHPUnit_Framework_TestCase
+{
+	public function testEmailWithoutAt()
+	{
+		$emailService = new \Szurubooru\Services\EmailService();
+
+		$this->setExpectedException(\DomainException::class);
+		$emailService->validateEmail('ghost');
+	}
+
+	public function testEmailWithoutDotInDomain()
+	{
+		$emailService = new \Szurubooru\Services\EmailService();
+
+		$this->setExpectedException(\DomainException::class);
+		$emailService->validateEmail('ghost@cemetery');
+	}
+
+	public function testValidEmail()
+	{
+		$emailService = new \Szurubooru\Services\EmailService();
+
+		$this->assertNull($emailService->validateEmail('ghost@cemetery.consulting'));
+	}
+}