doctest-script

#!/usr/bin/env python3
import doctest
import sys

try:
    script = sys.argv[1]
except IndexError:
    sys.stderr.write(f"error: no script given\n")
    sys.stderr.write(f"usage: {sys.argv[0]} <script>\n")
    sys.exit(1)

__name__ = f"<{script}>"
exec(open(script).read(), globals())

failed, total = doctest.testmod()

if failed:
    sys.stderr.write(f"error: {failed:,} test{'s' if failed != 1 else ''} failed\n")

if not total:
    sys.stderr.write(f"error: no tests found\n")

sys.exit(1 if failed or not total else 0)