To run:

php test.php [flags] [test-name-glob]

Runs through all files in inputs, compiles them, then compares to respective file in outputs. If there are any differences then the test will fail.

Add the -d flag to show the differences of failed tests. Defaults to showing differences with diff but you can set the tool by doing -d=toolname.

Pass the -C flag to save the output of the inputs to the appropriate file. This will overwrite any existing outputs. Use this when you want to save verified test results. Combine with a test-name-glob to selectively compile.

You can also run specific tests by passing in an argument that contains any part of the test name.

It's a syntetic test comparing lessc and lessphp output compiling twitter bootstrap; see bootstrap.sh for details.