test(request_id): add tests for request id middleware context handling

Add tests to verify that request_id is unique per request and correctly set in response headers. Tests include checks for isolation in async calls and persistence in synchronous requests.

Related to issue falconry#2260

examples/recipes/request_id_middleware.py

@@ -1,13 +1,13 @@
 # middleware.py
 
 from uuid import uuid4
-
-from context import ctx
-
+from .request_id_context import ctx
 
 class RequestIDMiddleware:
     def process_request(self, req, resp):
-        ctx.request_id = str(uuid4())
+        request_id = str(uuid4())
+        ctx.request_id = request_id  
+        req.context.request_id = request_id  
 
     # It may also be helpful to include the ID in the response
     def process_response(self, req, resp, resource, req_succeeded):

tests/test_recipes.py

@@ -2,10 +2,10 @@
 
 import falcon
 import falcon.testing
-
-from examples.recipes import request_id_context
 import asyncio
 
+from examples.recipes.request_id_middleware import RequestIDMiddleware
+
 class TestMultipartMixed:
     """Test parsing example from the now-obsolete RFC 1867:
 
@@ -143,27 +143,26 @@ def test_raw_path(self, asgi, app_kind, util):
         )
         assert result2.status_code == 200
         assert result2.json == {'cached': True}
-
-
+
 class TestRequestIDContext:
     @pytest.fixture
     def app(self):
-        app = falcon.App(middleware=[request_id_context.RequestIDMiddleware()])
+        app = falcon.App(middleware=[RequestIDMiddleware()])
         app.add_route('/test', self.RequestIDResource())
         return app
-    
+
     class RequestIDResource:
         def on_get(self, req, resp):
             resp.media = {'request_id': req.context.request_id}
 
-    @pytest.mark.asyncio
-    async def test_request_id_isolated_in_async(self, app):        
+    def test_request_id_isolated_in_async(self, app):
         async def make_request():
             client = falcon.testing.TestClient(app)
-            response = await client.simulate_get('/test')
+            response = client.simulate_get('/test')
             return response.json['request_id']
 
-        request_id1, request_id2 = await asyncio.gather(make_request(), make_request())
+        loop = asyncio.get_event_loop()
+        request_id1, request_id2 = loop.run_until_complete(asyncio.gather(make_request(), make_request()))
         assert request_id1 != request_id2
 
     def test_request_id_persistence(self, app):
@@ -176,3 +175,10 @@ def test_request_id_persistence(self, app):
         request_id2 = response.json['request_id']
 
         assert request_id1 != request_id2
+
+    def test_request_id_in_response_header(self, app):
+        client = falcon.testing.TestClient(app)
+
+        response = client.simulate_get('/test')
+        assert 'X-Request-ID' in response.headers
+        assert response.headers['X-Request-ID'] == response.json['request_id']