bogdibota / usequery Goto Github PK

This is a simple Create React App demonstrating a bug with Apollo's "useQuery" with the new version of React 16.3.0.

npm install
npm run start

Then, open the developer tools window and you'll sometimes see the warning:

index.js:1 Warning: Cannot update a component from inside the function body of a different component.
    in InnerComponent (at src/index.tsx:41)
    in WrapperComponent (at src/index.tsx:52)
    in ApolloProvider (at src/index.tsx:46)

Increasing the number of WrapperComponent will also increase the chance of the warning:

• 1 component will NEVER throw a warning
• 2 component will SOMETIMES throw a warning
• 3 component will ALWAYS throw 1 to 3 warnings

There are a number of ways to make this error disappear:

1. Remove the if (loading) check on line 37 in src/index.tsx.
2. The unique values of the WrapperComponent are set to the same value
3. Change requestDetails node to return the same value (server side)
4. Setting fetchPolicy: 'network-only' in the InnerComponent's query

From this I would infer that updates caused by cache changes are the cause of the warning.