Summary:
Our gentest works by console.logging the contents of the test it is generating to the browser powered by the driver. The driver then reads the logs and writes it to a file. An unfortunate side effect here is that we cannot console.log to debug how the gentest logic actually works since the driver is expecting formatted code. To get around this I had the driver filter out logs with a certain prefix and add that a helper that logs a message with this prefix to the scripts.
Reviewed By: NickGerleman
Differential Revision: D64011035
