public function testGuessExtension() { $file = new File($this->root . '/test.gif'); $this->assertEquals('gif', $file->guessExtension()); $file = new File($this->root . '/test'); $this->assertEquals('gif', $file->guessExtension()); $file = new File($this->root . '/other-file.example'); $this->assertNull($file->guessExtension()); $file = new File($this->root . '/.unknownextension'); $this->assertEquals('bin', $file->guessExtension()); }