Merge pull request #234 from lithomas1/dask-astype-copy

BUG: astype(..., copy=True) doesn't copy on dask

Author: ev-br

Diff for: array_api_compat/dask/array/_aliases.py

@@ -39,7 +39,22 @@
 
 isdtype = get_xp(np)(_aliases.isdtype)
 unstack = get_xp(da)(_aliases.unstack)
-astype = _aliases.astype
+
+def astype(
+    x: Array,
+    dtype: Dtype,
+    /,
+    *,
+    copy: bool = True,
+    device: Device | None = None
+) -> Array:
+    # TODO: respect device keyword?
+    if not copy and dtype == x.dtype:
+        return 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