This commit is not meant to completely test update-checkout, but rather create
some scaffolding for testing update-checkout so we can create starter bugs to
fill out the rest of the functionality. Once we have enough testing in place, we
can start refactoring/simplifying update-checkout.
Design
------
This is just a standard python unittest test suite except that the tests expect
an environment variable (UPDATECHECKOUT_TEST_WORKSPACE_DIR) to be set that
specifies the directory that the unittests have for creating mock git repos
during setup/teardown. lit invokes the test by calling the unittests with the
environment variable set to the appropriate temporary directory.
In this temporary directory, each test creates a pristine set of "fake" remote
repos and a test-config.json file that can be passed to update-checkout to work
with these "fake" remote repos. This allows each test that we write to test
various update-checkout functionalities against a pristime set of git repos. I
choose the git clone test, just b/c it was really simple.
NOTE: One can also run the tests locally using the script
test_update_checkout.sh that uses /tmp/workspace as the workspace directory.
