It’s close. action.type says “ONLINE”. You want to set the value to “online”.
Normally the action would probably have an status property in this case, setting it to action.status. You could add toLoweCase() for your action.type or hardcode it as “online”.
Also {state} doesn’t need curly bracers.
return Object.assign({}, state, { status : action.type.toLowerCase() });
You have 3 different return statements in the case. return newObject // newObject doesn’t exist. return // return what?
Now they won’t really matter because you have a return above them, this one: return object.assign( {},state,{status : action.type.toLowerCase()});
You have to use capital O in Object.