✅ add test for is{finite,inf,nan.nat}

Author: guan404ming

src/numpy-stubs/_typing/_ufunc.pyi

@@ -209,7 +209,7 @@ class _Call11Bool(Protocol):
         *,
         dtype: DTypeLike | None = None,
         **kwds: Unpack[_Kwargs2],
-    ) -> NDArray[np.bool] | np.bool: ...
+    ) -> NDArray[np.bool]: ...
     @overload  # (array-like) -> Array[bool] | bool
     def __call__(
         self,

test/static/accept/ufuncs.pyi

@@ -8,6 +8,7 @@ i8: np.int64
 f8: np.float64
 AR_f8: npt.NDArray[np.float64]
 AR_i8: npt.NDArray[np.int64]
+AR_bool: npt.NDArray[np.bool_]
 
 assert_type(np.absolute.types, list[str])
 
@@ -36,3 +37,19 @@ assert_type(np.vecdot(AR_f8, AR_f8), Any)
 
 assert_type(np.bitwise_count(i8), Any)
 assert_type(np.bitwise_count(AR_i8), npt.NDArray[Any])
+
+assert_type(np.isnan(f8), np.bool_)
+assert_type(np.isnan(AR_f8), npt.NDArray[np.bool_])
+assert_type(np.isnan(AR_f8, out=AR_bool), npt.NDArray[np.bool_])
+
+assert_type(np.isnat(f8), np.bool_)
+assert_type(np.isnat(AR_f8), npt.NDArray[np.bool_])
+assert_type(np.isnat(AR_f8, out=AR_bool), npt.NDArray[np.bool_])
+
+assert_type(np.isinf(f8), np.bool_)
+assert_type(np.isinf(AR_f8), npt.NDArray[np.bool_])
+assert_type(np.isinf(AR_f8, out=AR_bool), npt.NDArray[np.bool_])
+
+assert_type(np.isfinite(f8), np.bool_)
+assert_type(np.isfinite(AR_f8), npt.NDArray[np.bool_])
+assert_type(np.isfinite(AR_f8, out=AR_bool), npt.NDArray[np.bool_])