Declares a top-level getter that returns the outputs directory to which
Flutter Driver tests can write any output files. Timeline data defaults
to this directory.
This commit contains:
- FlutterDriver API for e2e tests usable in conjunction with package:test
- FlutterDriverExtension to be enabled by the application in order to
allow an external agent to connect to it and drive user interactions and
probe into the element tree
- initial implementations of tap, findByValueKey and getText commands (to
be expanded in future PRs)
