Most test runners have two stages: finding all tests, followed by executing them (or a subset thereof).
To find all tests in the repository, it is strongly recommended to
use the included
wpt manifest tool: the required behaviors are more
complex than what are documented (especially when it comes to
precedence of the various possibilities and some undocumented legacy
ways to define test types), and hence its behavior should be
considered the canonical definition of how to enumerate tests and find
their type in the repository.
For test execution, please read the documentation for the various test types
very carefully and then check your understanding on
the mailing list or IRC (webclient, join
#testing). It’s possible edge-case behavior isn’t properly