Add unit testing.

Original NumPy Commit: 81b97607339ac68b27cf72ba7923345d58e2895e

Author: eirrgang

array_api_strict/tests/test_asarray.py

@@ -0,0 +1,24 @@
+import numpy as np
+
+
+def test_fast_return():
+    """"""
+    a = np.array([1, 2, 3], dtype='i')
+    assert np.asarray(a) is a
+    assert np.asarray(a, dtype='i') is a
+    # This may produce a new view or a copy, but is never the same object.
+    assert np.asarray(a, dtype='l') is not a
+
+    unequal_type = np.dtype('i', metadata={'spam': True})
+    b = np.asarray(a, dtype=unequal_type)
+    assert b is not a
+    assert b.base is a
+
+    equivalent_requirement = np.dtype('i', metadata={'spam': True})
+    c = np.asarray(b, dtype=equivalent_requirement)
+    # A quirk of the metadata test is that equivalent metadata dicts are still
+    # separate objects and so don't evaluate as the same array type description.
+    assert unequal_type == equivalent_requirement
+    assert unequal_type is not equivalent_requirement
+    assert c is not b
+    assert c.dtype is equivalent_requirement