Fixed Resource.descriptor edge case

frictionless/metadata.py

@@ -163,7 +163,11 @@ def from_descriptor(
         # TODO: remove in next version
         # Transform with a base class in case the type is not available
         cls.metadata_transform(descriptor)
-        Class = cls.metadata_select_class(descriptor.get("type"))
+        type = descriptor.get("type")
+        class_type = vars(cls).get("type")
+        if isinstance(class_type, str):
+            type = class_type
+        Class = cls.metadata_select_class(type)
         Error = Class.metadata_Error or platform.frictionless_errors.MetadataError
         Class.metadata_transform(descriptor)
         errors = list(Class.metadata_validate(descriptor))

tests/resource/test_datatype.py

@@ -128,3 +128,37 @@ def test_resource_datatype_package_with_packagify(source):
     resource = Resource(source, packagify=True)
     assert resource.datatype == "package"
     assert isinstance(resource, resources.PackageResource)
+
+
+# Bugs
+
+DESCRIPTOR = {
+    "type": "json",
+    "name": "data",
+    "path": "data.json",
+    "scheme": "file",
+    "format": "json",
+    "mediatype": "text/json",
+    "encoding": "utf-8",
+}
+
+
+def test_resource_constructor_with_forced_datatype():
+    resource = Resource(path="data.json", datatype="table")
+    assert resource.type == "table"
+    assert resource.datatype == "table"
+    assert isinstance(resource, resources.TableResource)
+
+
+def test_resource_from_descriptor_with_forced_datatype():
+    resource = Resource.from_descriptor(DESCRIPTOR, datatype="table")
+    assert resource.type == "table"
+    assert resource.datatype == "table"
+    assert isinstance(resource, resources.TableResource)
+
+
+def test_resource_from_descriptor_with_class_datatype():
+    resource = resources.TableResource.from_descriptor(DESCRIPTOR)
+    assert resource.type == "table"
+    assert resource.datatype == "table"
+    assert isinstance(resource, resources.TableResource)