$ python runtests.py --help
Usage: Usage instructions for runtests.py.
All arguments are optional.
If --chrome is specified, chrome tests will be run instead of web content tests.

If --browser-chrome is specified, browser-chrome tests will be run instead of we
b content tests.
See for details on the logg
ing levels.

Options:
-h, --help show this help message and exit
--xre-path=XREPATH absolute path to directory containing XRE (probably
xulrunner)
--symbols-path=SYMBOLSPATH
absolute path to directory containing breakpad
symbols, or the URL of a zip file containing symbols
--debugger=DEBUGGER use the given debugger to launch the application
--debugger-args=DEBUGGERARGS
pass the given args to the debugger _before_ the
application on the command line
--debugger-interactive
prevents the test harness from redirecting stdout and
stderr for interactive debuggers
--setpref=PREF=VALUE defines an extra user preference
--close-when-done close the application when tests are done running
--appname=APP absolute path to application, overriding default
--utility-path=UTILITYPATH
absolute path to directory containing utility programs
(xpcshell, ssltunnel, certutil)
--certificate-path=CERTPATH
absolute path to directory containing certificate
store to use testing profile
--log-file=FILE file to which logging occurs
--autorun start running tests when the application starts
--timeout=TIMEOUT per-test timeout in seconds
--total-chunks=TOTALCHUNKS
how many chunks to split the tests up into
--this-chunk=THISCHUNK
which chunk to run
--chunk-by-dir=CHUNKBYDIR
group tests together in the same chunk that are in the
same top chunkByDir directories
--shuffle randomize test order
--console-level=LEVEL
one of DEBUG, INFO, WARNING, ERROR, FATAL to determine
the level of console logging
--file-level=LEVEL one of DEBUG, INFO, WARNING, ERROR, FATAL to determine
the level of file logging if a file has been
specified, defaulting to INFO
--chrome run chrome Mochitests
--test-path=TESTPATH start in the given directory's tests
--browser-chrome run browser chrome Mochitests
--a11y run accessibility Mochitests
--setenv=NAME=VALUE sets the given variable in the application's
environment
--browser-arg=ARG provides an argument to the test application
--leak-threshold=THRESHOLD
fail if the number of bytes leaked through refcounted
objects (or bytes in classes with MOZ_COUNT_CTOR and
MOZ_COUNT_DTOR) is greater than the given number
--fatal-assertions abort testing whenever an assertion is hit (requires a
debug build to be effective)
--extra-profile-file=EXTRAPROFILEFILES
copy specified files/dirs to testing profile
--profile-path=PROFILEPATH
Directory where the profile will be stored.This
directory will be deleted after the tests are finished
--use-vmware-recording
enables recording while the application is running
inside a VMware Workstation 7.0 or later VM