Fix CORS duplicate registration

homeassistant/components/http/cors.py

@@ -27,30 +27,36 @@ def setup_cors(app, origins):
         ) for host in origins
     })
 
-    def allow_cors(route, methods):
+    cors_added = set()
+
+    def _allow_cors(route, config=None):
         """Allow cors on a route."""
-        cors.add(route, {
-            '*': aiohttp_cors.ResourceOptions(
-                allow_headers=ALLOWED_CORS_HEADERS,
-                allow_methods=methods,
-            )
-        })
+        if hasattr(route, 'resource'):
+            path = route.resource
+        else:
+            path = route
+
+        path = path.canonical
+
+        if path in cors_added:
+            return
+
+        cors.add(route, config)
+        cors_added.add(path)
 
-    app['allow_cors'] = allow_cors
+    app['allow_cors'] = lambda route: _allow_cors(route, {
+        '*': aiohttp_cors.ResourceOptions(
+            allow_headers=ALLOWED_CORS_HEADERS,
+            allow_methods='*',
+        )
+    })
 
     if not origins:
         return
 
     async def cors_startup(app):
         """Initialize cors when app starts up."""
-        cors_added = set()
-
         for route in list(app.router.routes()):
-            if hasattr(route, 'resource'):
-                route = route.resource
-            if route in cors_added:
-                continue
-            cors.add(route)
-            cors_added.add(route)
+            _allow_cors(route)
 
     app.on_startup.append(cors_startup)

homeassistant/components/http/view.py

@@ -69,15 +69,13 @@ def register(self, app, router):
             handler = request_handler_factory(self, handler)
 
             for url in urls:
-                routes.append(
-                    (method, router.add_route(method, url, handler))
-                )
+                routes.append(router.add_route(method, url, handler))
 
         if not self.cors_allowed:
             return
 
-        for method, route in routes:
-            app['allow_cors'](route, [method.upper()])
+        for route in routes:
+            app['allow_cors'](route)
 
 
 def request_handler_factory(view, handler):

tests/components/http/test_cors.py

@@ -14,6 +14,7 @@
 from homeassistant.const import HTTP_HEADER_HA_AUTH
 from homeassistant.setup import async_setup_component
 from homeassistant.components.http.cors import setup_cors
+from homeassistant.components.http.view import HomeAssistantView
 
 
 TRUSTED_ORIGIN = 'https://home-assistant.io'
@@ -96,3 +97,34 @@ async def test_cors_preflight_allowed(client):
     assert req.headers[ACCESS_CONTROL_ALLOW_ORIGIN] == TRUSTED_ORIGIN
     assert req.headers[ACCESS_CONTROL_ALLOW_HEADERS] == \
         HTTP_HEADER_HA_AUTH.upper()
+
+
+async def test_cors_middleware_with_cors_allowed_view(hass):
+    """Test that we can configure cors and have a cors_allowed view."""
+    class MyView(HomeAssistantView):
+        """Test view that allows CORS."""
+
+        requires_auth = False
+        cors_allowed = True
+
+        def __init__(self, url, name):
+            """Initialize test view."""
+            self.url = url
+            self.name = name
+
+        async def get(self, request):
+            """Test response."""
+            return "test"
+
+    assert await async_setup_component(hass, 'http', {
+        'http': {
+            'cors_allowed_origins': ['http://home-assistant.io']
+        }
+    })
+
+    hass.http.register_view(MyView('/api/test', 'api:test'))
+    hass.http.register_view(MyView('/api/test', 'api:test2'))
+    hass.http.register_view(MyView('/api/test2', 'api:test'))
+
+    hass.http.app._on_startup.freeze()
+    await hass.http.app.startup()