TST: add FPU mode check also for pytest

1 files changed, 54 insertions, 0 deletions

diff --git a/numpy/conftest.py b/numpy/conftest.py
new file mode 100644
index 000000000..ea4197049
--- /dev/null
+++ b/numpy/conftest.py
@@ -0,0 +1,54 @@
+"""
+Pytest configuration and fixtures for the Numpy test suite.
+"""
+from __future__ import division, absolute_import, print_function
+
+import warnings
+import pytest
+
+from numpy.core.multiarray_tests import get_fpu_mode
+
+
+_old_fpu_mode = None
+_collect_results = {}
+
+
+@pytest.hookimpl()
+def pytest_itemcollected(item):
+    """
+    Check FPU precision mode was not changed during test collection.
+
+    The clumsy way we do it here is mainly necessary because numpy
+    still uses yield tests, which can execute code at test collection 
+    time.
+    """
+    global _old_fpu_mode
+
+    mode = get_fpu_mode()
+
+    if _old_fpu_mode is None:
+        _old_fpu_mode = mode
+    elif mode != _old_fpu_mode:
+        _collect_results[item] = (_old_fpu_mode, mode)
+        _old_fpu_mode = mode
+
+
+@pytest.fixture(scope="function", autouse=True)
+def check_fpu_mode(request):
+    """
+    Check FPU precision mode was not changed during the test.
+    """
+    old_mode = get_fpu_mode()
+    yield
+    new_mode = get_fpu_mode()
+
+    if old_mode != new_mode:
+        raise AssertionError("FPU precision mode changed from {0:#x} to {1:#x}"
+                             " during the test".format(old_mode, new_mode))
+
+    collect_result = _collect_results.get(request.node)
+    if collect_result is not None:
+        old_mode, new_mode = collect_result
+        raise AssertionError("FPU precision mode changed from {0:#x} to {1:#x}"
+                             " when collecting the test".format(old_mode, 
+                                                                new_mode))