public function testReadFromEmptyString() { $reader = new StringReader(''); $char = $reader->readCharacter(); $this->assertNull($char); $matcher = new WhitespaceMatcher(); $match = $reader->readTextMatch($matcher); $this->assertNull($match); $actualException = null; try { $reader->skip(1); } catch (\Exception $e) { $actualException = $e; } $this->assertNotNull($actualException); }