gistfile1.php

	/**
	 * Listen to the given stream and register incoming log hits
	 * @param resource $stream A stream with log lines
	 */
	public function listenTo($stream)
	{
		$lastFlushTime = time();
		$stopConditionCallback = $this->stopConditionCallback;
		while ($stopConditionCallback($stream)) {
			$this->receiveLine($stream);
			$lastFlushTime = $this->flushIfNeeded($lastFlushTime);
		}
	}

Yeah, this is somewhat complicated to test. Here are my thoughts:

• mock of the stream
• mock of stopConditionCallback
• mock of flushIfNeeded

Then your test would be making sure that whatever is happening inside receiveLine() is meeting your expectations.