After refetch fails, successful fetchMore sends updateQuery undefined previousResults

Intended outcome: After server downtime, during which a call to refetch fails, I would expect future successful queries using fetchMore to call the updateQuery function with previousResults from before the downtime.

Actual outcome: After failed calls to refetch, successful calls to fetchMore call the updateQuery function with a first argument (previousResults) value of undefined. At that point, there is no way to use the existing results.

A log looks something like this:

Server online, screen loading
Component rendering with data: {loading: true, networkStatus: 1, error: undefined}
Component rendering with data: {names: ["a", "b", "c", "d", "e"], loading: false, networkStatus: 7, error: undefined}
Server going offline
Attempting to sort (using `refetch` with variables as a promise)
Component rendering with data: {names: ["a", "b", "c", "d", "e"], loading: true, networkStatus: 2, error: undefined}
Component rendering with data: {names: ["a", "b", "c", "d", "e"], loading: false, networkStatus: 7, error: "Error: GraphQL error: ..."}
Sort failed
Server going online
Attempting to paginate
fetchMore's updateQuery method called with previousResults: undefined

How to reproduce the issue: Set up a repo that uses both refetch for sorting and fetchMore for pagination.

1. Load the initial results successfully
2. Go offline
3. Try sorting the results (which should fail)
4. Go online
5. Try paginating The updateQuery method is called with a first argument, previousResults, of undefined.

I’ve created a branch to demonstrate the behavior: https://github.com/treyp/react-apollo-error-template/tree/previousresults-undefined

This can also be found on CodeSandbox: https://codesandbox.io/s/github/treyp/react-apollo-error-template/tree/previousresults-undefined

Follow the steps above, just like the screen recording here, to reproduce.

Versions

  System:
    OS: macOS 10.14.6
  Binaries:
    Node: 10.15.3 - ~/.nvm/versions/node/v10.15.3/bin/node
    npm: 6.10.3 - ~/.nvm/versions/node/v10.15.3/bin/npm
  Browsers:
    Chrome: 76.0.3809.100
    Safari: 12.1.2
  npmPackages:
    apollo-cache-inmemory: ^1.6.3 => 1.6.3 
    apollo-client: ^2.6.4 => 2.6.4 
    apollo-link-batch-http: ^1.2.12 => 1.2.12 
    react-apollo: ^3.0.0 => 3.0.0 

[ManAnRuck]

i have the same issue, that fetchMore is for some queries very buggy.

when I fetch more directly it’s undefined. after ignoring this and run refetch the and then fetchMore/updateQuery it works fine. 🧐

[hwillson]

Can someone confirm if this is still an issue with @apollo/client@latest? I’ll close this for now, but happy to re-open if this is still happening. Thanks!