TST: Improve testing setup by introducing a new `weak_promotion` fixture

Unfortunately, this shows that the rational tests are still broken a bit.

1 files changed, 17 insertions, 0 deletions

diff --git a/numpy/conftest.py b/numpy/conftest.py
index fd5fdd77d..8aa6587ee 100644
--- a/numpy/conftest.py
+++ b/numpy/conftest.py
@@ -117,3 +117,20 @@ def add_np(doctest_namespace):
 @pytest.fixture(autouse=True)
 def env_setup(monkeypatch):
     monkeypatch.setenv('PYTHONHASHSEED', '0')
+
+
+@pytest.fixture(params=[True, False])
+def weak_promotion(request):
+    """
+    Fixture to ensure "legacy" promotion state or change it to use the new
+    weak promotion (plus warning).  `old_promotion` should be used as a
+    parameter in the function.
+    """
+    state = numpy._get_promotion_state()
+    if request.param:
+        numpy._set_promotion_state("weak_and_warn")
+    else:
+        numpy._set_promotion_state("legacy")
+
+    yield request.param
+    numpy._set_promotion_state(state)