let run-tests run optional code coverage tests.
to enable, set env var TEST_COVERAGE to non-empty string. run-tests will
print report after running.
after coverage run, file tests/.coverage will contain coverage data. use
tests/coverage.py to get more info, like annotated source code.
%% no merges expected
%% merge should fail
abort: 'b' already exists in the working dir and differs from remote
%% merge of b expected
merging for b
merging b
%%
Contents of b should be "this is file b1"
This is file b1
%% merge fails
abort: outstanding uncommitted changes
%% merge expected!
merging for b
merging b
%% merge of b should fail
abort: outstanding uncommitted changes
%% merge of b expected
merging for b
merging b