import builtins import os import subprocess import sys import textwrap def test_simple(): assert 1 + 1 == 2 def test_override_builtins(): import pylab ok_to_override = { '__name__', '__doc__', '__package__', '__loader__', '__spec__', 'any', 'all', 'sum', 'divmod' } overridden = {key for key in {*dir(pylab)} & {*dir(builtins)} if getattr(pylab, key) != getattr(builtins, key)} assert overridden <= ok_to_override def test_lazy_imports(): source = textwrap.dedent(""" import sys import matplotlib.figure import matplotlib.backend_bases import matplotlib.pyplot assert 'matplotlib._tri' not in sys.modules assert 'matplotlib._qhull' not in sys.modules assert 'matplotlib._contour' not in sys.modules assert 'urllib.request' not in sys.modules """) subprocess.check_call( [sys.executable, '-c', source], env={**os.environ, "MPLBACKEND": "", "MATPLOTLIBRC": os.devnull})