Fix create_dataset with data kwarg (#2638)

* Add failing test for #2631

* Fix create_dataset with data argument

Author: jni

src/zarr/core/group.py

@@ -1165,7 +1165,16 @@ async def create_dataset(
         .. deprecated:: 3.0.0
             The h5py compatibility methods will be removed in 3.1.0. Use `AsyncGroup.create_array` instead.
         """
-        return await self.create_array(name, shape=shape, **kwargs)
+        data = kwargs.pop("data", None)
+        # create_dataset in zarr 2.x requires shape but not dtype if data is
+        # provided. Allow this configuration by inferring dtype from data if
+        # necessary and passing it to create_array
+        if "dtype" not in kwargs and data is not None:
+            kwargs["dtype"] = data.dtype
+        array = await self.create_array(name, shape=shape, **kwargs)
+        if data is not None:
+            await array.setitem(slice(None), data)
+        return array
 
     @deprecated("Use AsyncGroup.require_array instead.")
     async def require_dataset(

tests/test_group.py

@@ -1137,6 +1137,18 @@ async def test_require_groups(store: LocalStore | MemoryStore, zarr_format: Zarr
     assert no_group == ()
 
 
+def test_create_dataset_with_data(store: Store, zarr_format: ZarrFormat) -> None:
+    """Check that deprecated create_dataset method allows input data.
+
+    See https://github.com/zarr-developers/zarr-python/issues/2631.
+    """
+    root = Group.from_store(store=store, zarr_format=zarr_format)
+    arr = np.random.random((5, 5))
+    with pytest.warns(DeprecationWarning):
+        data = root.create_dataset("random", data=arr, shape=arr.shape)
+    np.testing.assert_array_equal(np.asarray(data), arr)
+
+
 async def test_create_dataset(store: Store, zarr_format: ZarrFormat) -> None:
     root = await AsyncGroup.from_store(store=store, zarr_format=zarr_format)
     with pytest.warns(DeprecationWarning):