Fixing the cors middleware to address the KeyError via issue #767

hug/middleware.py

@@ -166,15 +166,18 @@ def match_route(self, reqpath):
         """Match a request with parameter to it's corresponding route"""
         route_dicts = [routes for _, routes in self.api.http.routes.items()][0]
         routes = [route for route, _ in route_dicts.items()]
-        if reqpath not in routes:
-            for route in routes:  # replace params in route with regex
-                reqpath = re.sub(r"^(/v\d*/?)", "/", reqpath)
-                base_url = getattr(self.api.http, "base_url", "")
-                reqpath = reqpath.replace(base_url, "", 1) if base_url else reqpath
-                if re.match(re.sub(r"/{[^{}]+}", ".+", route) + "$", reqpath, re.DOTALL):
-                    return route
-
-        return reqpath
+        # If the route is valid, it should return the valid route.
+        for route in routes:  # replace params in route with regex
+            reqpath = re.sub(r"^(/v\d*/?)", "/", reqpath)
+            # This will match the path with our without the trailing slash
+            if reqpath in route:
+                return route
+            base_url = getattr(self.api.http, "base_url", "")
+            reqpath = reqpath.replace(base_url, "", 1) if base_url else reqpath
+            if re.match(re.sub(r"/{[^{}]+}", ".+", route) + "$", reqpath, re.DOTALL):
+                return route
+        # If match route does not find a valid http route, it should return None
+        return None
 
     def process_response(self, request, response, resource, req_succeeded):
         """Add CORS headers to the response"""
@@ -185,12 +188,17 @@ def process_response(self, request, response, resource, req_succeeded):
             response.set_header("Access-Control-Allow-Origin", origin)
 
         if request.method == "OPTIONS":  # check if we are handling a preflight request
-            allowed_methods = set(
-                method
-                for _, routes in self.api.http.routes.items()
-                for method, _ in routes[self.match_route(request.path)].items()
-            )
-            allowed_methods.add("OPTIONS")
+            allowed_methods = set(["OPTIONS"])
+            # If we cannot match the route of a preflight request, send not_found from the origin.
+            route = self.match_route(request.path)
+            if not route:
+                self.api.http.not_found(request, response)
+            else:
+                allowed_methods.update(set(
+                    method
+                    for _, routes in self.api.http.routes.items()
+                    for method, _ in routes[route].items()
+                ))
 
             # return allowed methods
             response.set_header("Access-Control-Allow-Methods", ", ".join(allowed_methods))

tests/test_middleware.py

@@ -153,3 +153,13 @@ def get_demo(param):
     assert set(methods.split(",")) == set(["OPTIONS", "GET", "DELETE", "PUT"])
     assert set(allow.split(",")) == set(["OPTIONS", "GET", "DELETE", "PUT"])
     assert response.headers_dict["access-control-max-age"] == "10"
+
+    assert "404" in hug.test.get(hug_api, "/not_there").status
+
+    response = hug.test.options(hug_api, "/not_there")
+    methods = response.headers_dict["access-control-allow-methods"].replace(" ", "")
+    allow = response.headers_dict["allow"].replace(" ", "")
+    assert set(methods.split(",")) == set(["OPTIONS"])
+    assert set(allow.split(",")) == set(["OPTIONS"])
+    assert response.headers_dict["access-control-max-age"] == "10"
+    assert "404" in response.status