Check namespace decorators for interfaces

amarna/rules/gatherer_rules/DeclaredFunctionsGatherer.py

@@ -35,7 +35,11 @@ def code_element_function(self, tree: Tree) -> None:
 
         # find if the current tree is part of a @contract_interface
         # to ignore if unused in that case
-        for struct in self.original_tree.find_data("code_element_struct"):
+        namespace_struct = list(self.original_tree.find_data("code_element_namespace")) + list(
+            self.original_tree.find_data("code_element_struct")
+        )
+
+        for struct in namespace_struct:
             for child in struct.find_data("decorator_list"):
                 for decorator in child.find_data("identifier_def"):
                     if decorator.children[0] in ["contract_interface"]:

amarna/rules/local_rules/UnusedArgumentRule.py

@@ -79,7 +79,10 @@ def code_element_function(self, tree: Tree) -> None:
 
         # find if the current tree is part of a @contract_interface
         # to ignore unused arguments in that case
-        for struct in self.original_tree.find_data("code_element_struct"):
+        structures_namespaces = list(self.original_tree.find_data("code_element_struct")) + list(
+            self.original_tree.find_data("code_element_namespace")
+        )
+        for struct in structures_namespaces:
             for child in struct.find_data("decorator_list"):
                 for decorator in child.find_data("identifier_def"):
                     if decorator.children[0] == "contract_interface":

tests/interface_namespace.cairo

@@ -0,0 +1,8 @@
+@contract_interface
+namespace IBalanceContract {
+    func increase_balance(amount: felt) {
+    }
+
+    func get_balance() -> (res: felt) {
+    }
+}