Use cls argument in from_dict methods

Author: duckontheweb

pystac/catalog.py

@@ -904,7 +904,7 @@ def from_dict(
         if migrate:
             result = pystac.read_dict(d, href=href, root=root)
             if not isinstance(result, Catalog):
-                raise pystac.STACError(f"{result} is not a Catalog")
+                raise pystac.STACTypeError(f"{result} is not a Catalog")
             return result
 
         catalog_type = CatalogType.determine_type(d)
@@ -919,7 +919,7 @@ def from_dict(
 
         d.pop("stac_version")
 
-        cat = Catalog(
+        cat = cls(
             id=id,
             description=description,
             title=title,

pystac/collection.py

@@ -610,7 +610,7 @@ def from_dict(
 
         d.pop("stac_version")
 
-        collection = Collection(
+        collection = cls(
             id=id,
             description=description,
             extent=extent,

tests/test_catalog.py

@@ -1107,3 +1107,22 @@ def test_full_copy_4(self) -> None:
             ].get_absolute_href()
             assert href is not None
             self.assertTrue(os.path.exists(href))
+
+
+class CatalogSubClassTest(unittest.TestCase):
+    """This tests cases related to creating classes inheriting from pystac.Catalog to
+    ensure that inheritance, class methods, etc. function as expected."""
+
+    TEST_CASE_1 = TestCases.get_path("data-files/catalogs/test-case-1/catalog.json")
+
+    class BasicCustomCatalog(pystac.Catalog):
+        pass
+
+    def setUp(self) -> None:
+        self.stac_io = pystac.StacIO.default()
+
+    def test_from_dict_returns_subclass(self) -> None:
+
+        catalog_dict = self.stac_io.read_json(self.TEST_CASE_1)
+        custom_catalog = self.BasicCustomCatalog.from_dict(catalog_dict)
+        self.assertIsInstance(custom_catalog, self.BasicCustomCatalog)

tests/test_collection.py

@@ -264,3 +264,22 @@ def test_from_items(self) -> None:
 
         self.assertEqual(interval[0], datetime(2000, 1, 1, 12, 0, 0, 0, tzinfo=tz.UTC))
         self.assertEqual(interval[1], datetime(2001, 1, 1, 12, 0, 0, 0, tzinfo=tz.UTC))
+
+
+class CollectionSubClassTest(unittest.TestCase):
+    """This tests cases related to creating classes inheriting from pystac.Catalog to
+    ensure that inheritance, class methods, etc. function as expected."""
+
+    MULTI_EXTENT = TestCases.get_path("data-files/collections/multi-extent.json")
+
+    class BasicCustomCollection(pystac.Collection):
+        pass
+
+    def setUp(self) -> None:
+        self.stac_io = pystac.StacIO.default()
+
+    def test_from_dict_returns_subclass(self) -> None:
+
+        collection_dict = self.stac_io.read_json(self.MULTI_EXTENT)
+        custom_collection = self.BasicCustomCollection.from_dict(collection_dict)
+        self.assertIsInstance(custom_collection, self.BasicCustomCollection)

tests/test_item.py

@@ -698,3 +698,22 @@ def test_asset_updated(self) -> None:
         new_a1_value = cm.get_updated(item.assets["analytic"])
         self.assertEqual(new_a1_value, set_value)
         self.assertEqual(cm.updated, item_value)
+
+
+class ItemSubClassTest(unittest.TestCase):
+    """This tests cases related to creating classes inheriting from pystac.Catalog to
+    ensure that inheritance, class methods, etc. function as expected."""
+
+    SAMPLE_ITEM = TestCases.get_path("data-files/item/sample-item.json")
+
+    class BasicCustomItem(pystac.Item):
+        pass
+
+    def setUp(self) -> None:
+        self.stac_io = pystac.StacIO.default()
+
+    def test_from_dict_returns_subclass(self) -> None:
+
+        item_dict = self.stac_io.read_json(self.SAMPLE_ITEM)
+        custom_item = self.BasicCustomItem.from_dict(item_dict)
+        self.assertIsInstance(custom_item, self.BasicCustomItem)