Weird subscribeToMore behavior

[rafbgarcia]

I was implementing GraphQL subscriptions in my project, but I couldn't make subscribeToMore rerender the component.

After investigation, I found out that it was because I wasn't selecting the same fields in my subscription that I had selected in my query.

If I select either the same fields or more fields in the subscription, it rerenders just fine.

Intended outcome:

I'm not sure if this is the correct behavior, it seemed weird to me so I wanted to bring it up.

How to reproduce the issue:

I prepared a codesandbox with 3 scenarios, visiting the link below should take you to subscriptions_link.js with the firstScenario running.

I left some comments in there for y'all to play with it, but please let me know if you have questions.

https://codesandbox.io/s/wild-silence-7sl9w?file=/src/graphql/subscription_link.js:145-233

Versions

✗ npx envinfo@latest --preset apollo --clipboard
npx: installed 1 in 0.945s

  System:
    OS: macOS 11.2.3
  Binaries:
    Node: 10.17.0 - ~/.asdf/installs/nodejs/10.17.0/bin/node
    Yarn: 1.13.0 - ~/.asdf/shims/yarn
    npm: 6.11.3 - ~/.asdf/installs/nodejs/10.17.0/bin/npm
  Browsers:
    Chrome: 90.0.4430.93
    Firefox: 88.0.1
    Safari: 14.0.3
  npmPackages:
    @apollo/client: ^3.3.16 => 3.3.16
    apollo-fetch: ^0.7.0 => 0.7.0
    apollo-link-core: ^0.5.4 => 0.5.4