TST: add test for unsigned bins monotonicity check, see #9222

1 files changed, 8 insertions, 0 deletions

diff --git a/numpy/lib/tests/test_function_base.py b/numpy/lib/tests/test_function_base.py
index 4000b55f5..6cd990634 100644
--- a/numpy/lib/tests/test_function_base.py
+++ b/numpy/lib/tests/test_function_base.py
@@ -1771,6 +1771,14 @@ class TestHistogram(TestCase):
         hist, edges = np.histogram(arr, bins=30, range=(-0.5, 5))
         self.assertEqual(hist[-1], 1)
 
+    def test_unsigned_monotonicity_check(self):
+        # Ensures ValueError is raised if bins not increasing monotonically
+        # when bins contain unsigned values (see #9222)
+        arr = np.array([2])
+        bins = np.array([1, 3, 1], dtype='uint64')
+        with assert_raises(ValueError):
+            hist, edges = np.histogram(arr, bins=bins)
+
 
 class TestHistogramOptimBinNums(TestCase):
     """