prevent child component to re-render below context provider with memo - reactjs

Question

I am using a context provider in React to share data across several components. However since a value gets changed from one of my subcomponents, it rerenders all of my other components which partly leads to performance issues. So I want to prevent my child components to rerender. I tried using React.memo() but it's still rendering whenever I set the state of the Context Provider.
const Authenticator = React.memo(() => {
const [myChat, setMyChat] = useContext(ChatContext);
console.log("rerender"); // gets called everytime on click
return (
<Button
title="click me"
onPress={() => setMyChat({ text: "hello" })}
></Button>
);
});
My Context Provider looks like this:
const ChatProvider = ({ children }) => {
const [myChat, setMyChat] = useState([]);
return (
<ChatContext.Provider value={[myChat, setMyChat]}>
{children}
</ChatContext.Provider>
);
};
My App.js looks like this:
<ChatProvider>
<Authenticator />
</ChatProvider>

Answer 1

React.Memo doesn't help since you are calling the useContext hook which will cause the component to re-render every time the value from the provider changes. You should consider splitting your context into two separate contexts: one for the value, one for the state updater.
const ChatProvider = ({ children }) => {
const [myChat, setMyChat] = useState([])
return (
<ChatDispatchContext.Provider value={setMyChat}>
<ChatValueContext.Provider value={myChat}>
{children}
</ChatValueContext.Provider>
</ChatDispatchContext.Provider>
)
}
Then, update your Authenticator component to the following:
const Authenticator = React.memo(() => {
const setMyChat = useContext(ChatDispatchContext)
return (
<Button
title="click me"
onPress={() => setMyChat({ text: "hello" })}
></Button>
)
})