address feedback

Co-Authored-By: Guido Imperiale <6213168+crusaderky@users.noreply.github.com>

array_api_compat/dask/array/_aliases.py

@@ -40,13 +40,25 @@
 isdtype = get_xp(np)(_aliases.isdtype)
 unstack = get_xp(da)(_aliases.unstack)
 
-def astype(x: Array, dtype: Dtype, /, *, copy: bool = True) -> Array:
+def astype(
+    x: Array,
+    dtype: Dtype,
+    /,
+    *,
+    copy: bool = True,
+    device: Device | None = None
+) -> Array:
+    if device is not None:
+        raise NotImplementedError(
+            "The device keyword is not implemented yet for "
+            "array-api-compat wrapped dask"
+        )
     if not copy and dtype == x.dtype:
         return x
-    # dask astype doesn't respect copy=True so copy
-    # manually via numpy
-    x = np.array(x, dtype=dtype, copy=copy)
-    return da.from_array(x)
+    # dask astype doesn't respect copy=True,
+    # so call copy manually afterwards
+    x = x.astype(dtype)
+    return x.copy() if copy else x
 
 # Common aliases
 

tests/test_common.py

@@ -272,16 +272,3 @@ def test_asarray_copy(library):
         assert all(b[0] == 1.0)
     else:
         assert all(b[0] == 0.0)
-
-@pytest.mark.parametrize("library", wrapped_libraries)
-def test_astype_copy(library):
-    # array-api-tests currently doesn't check copy=True
-    # makes a copy when dtypes are the same
-    # so we check that here
-    xp = import_(library, wrapper=True)
-    a = xp.asarray([1])
-    b = xp.astype(a, a.dtype, copy=True)
-
-    a[0] = 10
-
-    assert b[0] == 1