fix: Add a DummyErrorHandler (GoogleCloudPlatform#137)

* Remove unused imports

* Add failing test

* Add DummyErrorHandler

Author: di

src/functions_framework/__init__.py

@@ -348,3 +348,14 @@ def __call__(self, *args, **kwargs):
 
 
 app = LazyWSGIApp()
+
+
+class DummyErrorHandler:
+    def __init__(self):
+        pass
+
+    def __call__(self, *args, **kwargs):
+        return self
+
+
+errorhandler = DummyErrorHandler()

tests/test_cloudevent_functions.py

@@ -16,9 +16,9 @@
 
 import pytest
 
-from cloudevents.http import CloudEvent, from_http, to_binary, to_structured
+from cloudevents.http import CloudEvent, to_binary, to_structured
 
-from functions_framework import LazyWSGIApp, create_app, exceptions
+from functions_framework import create_app
 
 TEST_FUNCTIONS_DIR = pathlib.Path(__file__).resolve().parent / "test_functions"
 TEST_DATA_DIR = pathlib.Path(__file__).resolve().parent / "test_data"

tests/test_functions.py

@@ -25,7 +25,7 @@
 
 import functions_framework
 
-from functions_framework import LazyWSGIApp, create_app, exceptions
+from functions_framework import LazyWSGIApp, create_app, errorhandler, exceptions
 
 TEST_FUNCTIONS_DIR = pathlib.Path.cwd() / "tests" / "test_functions"
 
@@ -454,6 +454,12 @@ def test_lazy_wsgi_app(monkeypatch, target, source, signature_type):
     ]
 
 
+def test_dummy_error_handler():
+    @errorhandler("foo", bar="baz")
+    def function():
+        pass
+
+
 def test_class_in_main_is_in_right_module():
     source = TEST_FUNCTIONS_DIR / "module_is_correct" / "main.py"
     target = "function"