Router context breaking change in v8.0.0-canary.6

[jaydenseric]

Bug report

Describe the bug

The next/router migration to React.createContext in #6030 (Next.js v8.0.0-canary.6) is a breaking change for the GraphQL SSR related examples such as with-graphql-react and probably with-apollo.

To Reproduce

In the with-graphql-react example, update the next dependency to 8.0.0-canary.6 and replace the contents of pages/index.js with:

import { Query } from 'graphql-react'
import { RouterContext } from 'next/router'

export default () => (
  <RouterContext.Consumer>
    {router => {
      console.log(router)
      return null
    }}
  </RouterContext.Consumer>
)

With npm run dev, in terminal you will see first undefined (bad) for the GraphQL preload render and then a router instance when the final SSR happens:

I imagine this reproduction would work for the with-apollo examples too:

https://github.com/zeit/next.js/blob/v8.0.0-canary.6/examples/with-apollo/lib/with-apollo-client.js#L27

Expected behavior

Perhaps the API would be non-breaking from Next.js v7 if <RouterContext.Consumer> was used inside of <App> instead of immediately outside.

System information

• Version of Next.js: v8.0.0-canary.6

Additional context

Is this breaking change intentional? If so, I can work it in to next-graphql-react and cut a new release for Next.js v8 compatibility.

The Apollo examples will also need updating.

[timneutkens]

Right so the issue is the non-standard rendering of the React tree in getInitialProps, I guess the best solution would be to wrap Component in the provider before Component is actually passed to _app, so that when it's rendered the value is provided automatically. This would require no user-side changes.

[todesstoss]

@timneutkens Hello, i'm currently using Next.js v8.1.0, and as I understand after implementation of useRouter, Provider implemented with a same issue described here, legacy context witRouter works just fine, but useRouter breaks my getDataFromTree in with-apollo example, as useRouter return null in this method, is it smth that will be fixed or it is expected behaviour? Thanks

[timneutkens]

See #7075 (comment)

[todesstoss]

Yes, sure, but i think it's smth you should be aware of