Instance check constants with SupportsFloat

Author: honno

array_api_tests/test_constants.py

@@ -1,4 +1,5 @@
 import math
+from typing import Any, SupportsFloat
 
 import pytest
 
@@ -7,6 +8,10 @@
 from .typing import Array
 
 
+def assert_scalar_float(name: str, c: Any):
+    assert isinstance(c, SupportsFloat), f"{name}={c!r} does not look like a float"
+
+
 def assert_0d_float(name: str, x: Array):
     assert dh.is_float_dtype(
         x.dtype
@@ -17,16 +22,18 @@ def assert_0d_float(name: str, x: Array):
 def test_irrational(name, n):
     assert hasattr(xp, name)
     c = getattr(xp, name)
+    assert_scalar_float(name, c)
     floor = math.floor(n)
-    assert c > floor, f"xp.{name}={c} <= {floor}"
+    assert c > floor, f"xp.{name}={c!r} <= {floor}"
     ceil = math.ceil(n)
-    assert c < ceil, f"xp.{name}={c} >= {ceil}"
+    assert c < ceil, f"xp.{name}={c!r} >= {ceil}"
     x = xp.asarray(c)
     assert_0d_float("name", x)
 
 
 def test_inf():
     assert hasattr(xp, "inf")
+    assert_scalar_float("inf", xp.inf)
     assert math.isinf(xp.inf)
     assert xp.inf > 0, "xp.inf not greater than 0"
     x = xp.asarray(xp.inf)
@@ -36,6 +43,7 @@ def test_inf():
 
 def test_nan():
     assert hasattr(xp, "nan")
+    assert_scalar_float("nan", xp.nan)
     assert math.isnan(xp.nan)
     assert xp.nan != xp.nan, "xp.nan should not have equality with itself"
     x = xp.asarray(xp.nan)