Add tests for the class hierarchies

Author: oliverklee

tests/Unit/Parsing/OutputExceptionTest.php

@@ -6,12 +6,21 @@
 
 use PHPUnit\Framework\TestCase;
 use Sabberworm\CSS\Parsing\OutputException;
+use Sabberworm\CSS\Parsing\SourceException;
 
 /**
  * @covers \Sabberworm\CSS\Parsing\OutputException
  */
 final class OutputExceptionTest extends TestCase
 {
+    /**
+     * @test
+     */
+    public function extendsSourceException(): void
+    {
+        self::assertInstanceOf(SourceException::class, new OutputException('foo'));
+    }
+
     /**
      * @test
      */

tests/Unit/Parsing/UnexpectedEOFExceptionTest.php

@@ -6,12 +6,21 @@
 
 use PHPUnit\Framework\TestCase;
 use Sabberworm\CSS\Parsing\UnexpectedEOFException;
+use Sabberworm\CSS\Parsing\UnexpectedTokenException;
 
 /**
  * @covers \Sabberworm\CSS\Parsing\UnexpectedEOFException
  */
 final class UnexpectedEOFExceptionTest extends TestCase
 {
+    /**
+     * @test
+     */
+    public function extendsUnexpectedTokenException(): void
+    {
+        self::assertInstanceOf(UnexpectedTokenException::class, new UnexpectedEOFException('expected', 'found'));
+    }
+
     /**
      * @test
      */

tests/Unit/Parsing/UnexpectedTokenExceptionTest.php

@@ -5,13 +5,22 @@
 namespace Sabberworm\CSS\Tests\Unit\Parsing;
 
 use PHPUnit\Framework\TestCase;
+use Sabberworm\CSS\Parsing\SourceException;
 use Sabberworm\CSS\Parsing\UnexpectedTokenException;
 
 /**
  * @covers \Sabberworm\CSS\Parsing\UnexpectedTokenException
  */
 final class UnexpectedTokenExceptionTest extends TestCase
 {
+    /**
+     * @test
+     */
+    public function extendsSourceException(): void
+    {
+        self::assertInstanceOf(SourceException::class, new UnexpectedTokenException('expected', 'found'));
+    }
+
     /**
      * @test
      */