Add attrs to future swath definition

pyresample/future/geometry/swath.py

@@ -19,4 +19,40 @@
 
 from __future__ import annotations
 
-from pyresample.geometry import CoordinateDefinition, SwathDefinition  # noqa
+from pyresample.geometry import CoordinateDefinition  # noqa
+from pyresample.geometry import SwathDefinition as LegacySwathDefinition
+
+
+class SwathDefinition(LegacySwathDefinition):
+    """Swath defined by lons and lats.
+
+    Parameters
+    ----------
+    lons : numpy array
+    lats : numpy array
+    crs: pyproj.CRS,
+       The CRS to use. longlat on WGS84 by default.
+    nprocs : int, optional
+        Number of processor cores to be used for calculations.
+    attrs: dict,
+       A dictionary made to store metadata.
+
+    Attributes
+    ----------
+    shape : tuple
+        Swath shape
+    size : int
+        Number of elements in swath
+    ndims : int
+        Swath dimensions
+    lons : object
+        Swath lons
+    lats : object
+        Swath lats
+    cartesian_coords : object
+        Swath cartesian coordinates
+    """
+
+    def __init__(self, lons, lats, crs=None, nprocs=1, attrs=None):
+        super().__init__(lons, lats, crs=crs, nprocs=nprocs)
+        self.attrs = attrs or {}

pyresample/test/test_geometry/test_swath.py

@@ -462,3 +462,11 @@ def assert_np_dict_allclose(dict1, dict2):
             np.testing.assert_allclose(val, dict2[key])
         except TypeError:
             assert val == dict2[key]
+
+
+def test_future_swath_has_attrs():
+    """Test that future SwathDefinition has attrs."""
+    from pyresample.future.geometry import SwathDefinition
+    lons, lats = _gen_swath_lons_lats()
+    swath = SwathDefinition(lons, lats)
+    assert isinstance(swath.attrs, dict)