Use object spread.

Author: davidlehn

lib/context.js

@@ -80,7 +80,7 @@ api.process = async ({
   // store original options to use when replaying events
   const originalOptions = options;
   // shallow clone options with custom event handler
-  options = Object.assign({}, options, {eventHandler});
+  options = {...options, eventHandler};
 
   // resolve contexts
   const resolved = await options.contextResolver.resolve({