add XCom tests for local attribute callables (#23)

tests/pylint_airflow/checkers/test_xcom.py

@@ -136,6 +136,34 @@ def aux_func():
 
         assert result == expected_result
 
+    @pytest.mark.xfail(reason="Not yet implemented", raises=AssertionError, strict=True)
+    def test_should_detect_local_function_callables_as_attributes(self):
+        test_code = """
+        from airflow.operators.python_operator import PythonOperator
+        from types import SimpleNamespace
+
+        def task_func():
+            print("bupkis")
+
+        def aux_func():
+            return 2 + 2
+
+        obj = SimpleNamespace()
+        obj.func = aux_func
+
+        local_task = PythonOperator(task_id="local_task", python_callable=task_func)
+        another_task = PythonOperator(task_id="another_task", python_callable=obj.func)
+        """
+        ast = astroid.parse(test_code)
+        result = get_task_ids_to_python_callable_specs(ast)
+
+        expected_result = {
+            "local_task": PythonOperatorSpec(ast.body[6].value, "task_func"),
+            "another_task": PythonOperatorSpec(ast.body[7].value, "obj.func"),
+        }
+
+        assert result == expected_result
+
 
 class TestGetXComsFromTasks:
     """Tests the get_xcoms_from_tasks helper function which detects the xcom pushes and pulls."""
@@ -217,7 +245,38 @@ def test_should_skip_imported_callable_as_name(self):
 
         assert result == ({}, set())
 
-    def test_should_detect_xcom_push_tasks(self):
+    @pytest.mark.xfail(
+        reason="Not yet implemented", raises=astroid.AttributeInferenceError, strict=True
+    )
+    def test_should_skip_local_function_callables_as_attributes(self):
+        test_code = """
+        from airflow.operators.python_operator import PythonOperator
+        from types import SimpleNamespace
+
+        def task_func():
+            print("bupkis")
+
+        def aux_func():
+            return 2 + 2
+
+        obj = SimpleNamespace()
+        obj.func = aux_func
+
+        local_task = PythonOperator(task_id="local_task", python_callable=task_func)
+        another_task = PythonOperator(task_id="another_task", python_callable=obj.func)
+        """
+        ast = astroid.parse(test_code)
+
+        test_task_ids_to_python_callable_specs = {
+            "local_task": PythonOperatorSpec(ast.body[6].value, "task_func"),
+            "another_task": PythonOperatorSpec(ast.body[7].value, "obj.func"),
+        }
+
+        result = get_xcoms_from_tasks(ast, test_task_ids_to_python_callable_specs)
+
+        assert result == ({}, set())
+
+    def test_should_detect_xcom_push_tasks_from_local_function_callables(self):
         test_code = """
         from airflow.operators.python_operator import PythonOperator
 
@@ -261,7 +320,7 @@ def another_func():
 
         assert result == expected_result
 
-    def test_should_detect_xcom_pull_tasks(self):
+    def test_should_detect_xcom_pull_tasks_from_local_function_callables(self):
         test_code = """
         from airflow.operators.python_operator import PythonOperator