# Various C+ fixes/improvements - Wed / Thurs 18th-19th Nov, 2020 Lots of small, mostly unremarkable fixes and improvements to C+ as we gear up for v1 relaunch. In React Navigation, you navigate to a **screen** inside a stack like so: ```typescript= navigate('Stack', { screen: 'MyScreen', params: { thing } } ``` Yup can take a `trim` call to ensure no empty whitespaced messaged can be submitted: ```typescript= yup.string().trim().required('You must enter a message') ``` Added some toast messages to the app for when mutations (such as commenting) fails to provide some info for the user using [react-native-toast-message](https://github.com/calintamas/react-native-toast-message). Had to write TS types, so should PR them to the library for others. ###### tags: `programmingjournal` `C+` `2020` `nestednavigation` `yup` `trim` `toast`