add test with -OO (#17988)

linchiwei123 · web-flow · commit 019a75231fd8 · 2020-07-21T21:00:47.000-04:00
diff --git a/lib/matplotlib/tests/test_matplotlib.py b/lib/matplotlib/tests/test_matplotlib.py
@@ -42,3 +42,18 @@ def parse(key):
             set(matplotlib.rcsetup.interactive_bk))
     assert (set(parse('- non-interactive backends:\n')) ==
             set(matplotlib.rcsetup.non_interactive_bk))
+
+
+def test_importable_with__OO():
+    """
+    When using -OO or export PYTHONOPTIMIZE=2, docstrings are discarded,
+    this simple test may prevent something like issue #17970.
+    """
+    program = (
+        "import matplotlib as mpl; "
+        "import matplotlib.pyplot as plt; "
+        "import matplotlib.cbook as cbook; "
+        "import matplotlib.patches as mpatches"
+    )
+    cmd = [sys.executable, "-OO", "-c", program]
+    assert subprocess.call(cmd) == 0
