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.

#!/bin/sh

hg init
echo 123 > a
hg add a
hg commit -m "first" -d "1000000 0" a
mkdir sub
echo 321 > sub/b
hg add sub/b
hg commit -m "second" -d "1000000 0" sub/b
cat sub/b
hg co 0
cat sub/b 2>/dev/null || echo "sub/b not present"
ls sub 2>/dev/null || echo "sub not present"

true