make assertion visible to pytest

richardsheridan · richardsheridan · commit af9d83f9c160 · 2021-12-22T07:38:52.000-05:00
diff --git a/lib/matplotlib/tests/test_backends_interactive.py b/lib/matplotlib/tests/test_backends_interactive.py
@@ -336,10 +336,6 @@ def _test_figure_leak():
     if len(sys.argv) >= 2:  # Second argument is json-encoded rcParams.
         rcParams.update(json.loads(sys.argv[1]))
 
-    # We can't yet directly identify the leak
-    # so test with a memory growth threshold
-    ACCEPTABLE_MEMORY_LEAKAGE = 1_000_000
-
     # Warmup cycle, this reasonably allocates a lot
     p = psutil.Process()
     fig = plt.figure()
@@ -351,14 +347,23 @@ def _test_figure_leak():
     fig = plt.figure()
     plt.close(fig)
     growth = p.memory_full_info().uss - mem
-    assert growth < ACCEPTABLE_MEMORY_LEAKAGE, "Memory leakage too high"
+
+    print(growth)
 
 
 @pytest.mark.parametrize("env", _get_testable_interactive_backends())
 def test_figure_leak_20490(env):
     pytest.importorskip("psutil", reason="psutil needed to run this test")
-    subprocess.run(
+
+    # We can't yet directly identify the leak
+    # so test with a memory growth threshold
+    acceptable_memory_leakage = 1_000_000
+
+    result = subprocess.run(
         [sys.executable, "-c",
          inspect.getsource(_test_figure_leak) + "\n_test_figure_leak()"],
         env={**os.environ, "SOURCE_DATE_EPOCH": "0", **env},
-        timeout=_test_timeout, check=True,)
+        timeout=_test_timeout, stdout=subprocess.PIPE, check=True)
+
+    growth = int(result.stdout)
+    assert growth <= acceptable_memory_leakage
