def _autogen_options_headers()

in chalice/local.py [0:0]

• 14 lines of code
• 5 McCabe index (conditional complexity)

    def _autogen_options_headers(self, lambda_event: EventType) -> HeaderType:
        route_key = lambda_event['requestContext']['resourcePath']
        route_dict = self._app_object.routes[route_key]
        route_methods = [method for method in route_dict.keys()
                         if route_dict[method].cors is not None]

        # If there are no views with CORS enabled
        # then OPTIONS is the only allowed method.
        if not route_methods:
            return {'Access-Control-Allow-Methods': 'OPTIONS'}

        # Chalice ensures that routes with multiple views have the same
        # CORS configuration, so if any view has a CORS Config we can use
        # that config since they will all be the same.
        cors_config = route_dict[route_methods[0]].cors
        cors_headers = cors_config.get_access_control_headers()

        # We need to add OPTIONS since it is not a part of the CORSConfig
        # object. APIGateway handles this entirely based on the API definition.
        # So our local version needs to add this manually to our set of allowed
        # headers.
        route_methods.append('OPTIONS')

        # The Access-Control-Allow-Methods header is not added by the
        # CORSConfig object it is added to the API Gateway route during
        # deployment, so we need to manually add those headers here.
        cors_headers.update({
            'Access-Control-Allow-Methods': '%s' % ','.join(route_methods)
        })
        return cors_headers