public function testExtractNextMessage()
{
// Make sure the buffer is empty to start
$this->assertEquals('', $this->stomp->_getBuffer());
$this->assertFalse($this->stomp->_bufferContainsMessage());
// Fill the buffer up with 3 messages
$this->stomp->_appendToBuffer("MESSAGE1\n\nBODY1\n");
$this->stomp->_appendToBuffer("MESSAGE2\n\nBODY2\n");
$this->stomp->_appendToBuffer("MESSAGE3\n\nBODY3\n");
$this->assertEquals("MESSAGE1\n\nBODY1\nMESSAGE2\n\nBODY2\nMESSAGE3\n\nBODY3\n", $this->stomp->_getBuffer());
$this->assertTrue($this->stomp->_bufferContainsMessage());
// Extract all 3 sequentially
$this->assertEquals("MESSAGE1\n\nBODY1\n", $this->stomp->_extractNextMessage());
$this->assertEquals("MESSAGE2\n\nBODY2\nMESSAGE3\n\nBODY3\n", $this->stomp->_getBuffer());
$this->assertEquals("MESSAGE2\n\nBODY2\n", $this->stomp->_extractNextMessage());
$this->assertEquals("MESSAGE3\n\nBODY3\n", $this->stomp->_getBuffer());
$this->assertEquals("MESSAGE3\n\nBODY3\n", $this->stomp->_extractNextMessage());
$this->assertEquals("", $this->stomp->_getBuffer());
// Now that the buffer is empty, add another message
$this->stomp->_appendToBuffer("MESSAGE4\n\nBODY4\n");
$this->assertEquals("MESSAGE4\n\nBODY4\n", $this->stomp->_getBuffer());
// Extract that message
$this->assertEquals("MESSAGE4\n\nBODY4\n", $this->stomp->_extractNextMessage());
$this->assertEquals("", $this->stomp->_getBuffer());
// verify that trying to extract from an empty buffer returns empty string
$this->stomp->_appendToBuffer("");
$this->assertEquals("", $this->stomp->_getBuffer());
// Now that the buffer is empty, add another message
// This is to verify that extracting a message from an empty buffer doesn't break something
$this->stomp->_appendToBuffer("MESSAGE5\n\nBODY5\n");
$this->assertEquals("MESSAGE5\n\nBODY5\n", $this->stomp->_getBuffer());
// Extract that message
$this->assertEquals("MESSAGE5\n\nBODY5\n", $this->stomp->_extractNextMessage());
$this->assertEquals("", $this->stomp->_getBuffer());
// verify that trying to extract from an empty buffer returns empty string
$this->stomp->_appendToBuffer("");
$this->assertEquals("", $this->stomp->_getBuffer());
}