Previous data returned when changing variables and fetchPolicy is network-only (Reproduction Provided)

[dylanwulf]

Intended outcome:
If I change variable values when fetchPolicy === 'network-only', then data should immediately become undefined while the results are being fetched from the server. This seemed to work correctly in v3.0.0 - v3.0.2, but broke in v3.1.0.

Actual outcome:
When I change the variable values, data still holds the previous data which was associated with the previous variable values.

How to reproduce the issue:
https://github.com/dylanwulf/react-apollo-error-template (look at the console as you click the radio buttons)

Possibly related to #7058 and #7048

Versions

System:
    OS: Windows 10 10.0.19042
Binaries:
    Node: 14.16.0 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.21.1 - C:\Program Files (x86)\Yarn\bin\yarn.CMD
    npm: 6.14.11 - C:\Program Files\nodejs\npm.CMD
Browsers:
    Chrome: 89.0.4389.114
    Edge: Spartan (44.19041.423.0), Chromium (89.0.774.75)
npmPackages:
    @apollo/client: ^3.3.11 => 3.3.11

[dylanwulf]

Also, if you change notifyOnNetworkStatusChange to true, then it will first return results for the previous variables, then it will return CACHED results for the current variables, and finally it will return the fetched results for the current variables. Is network-only supposed to return cached results when you change the variables? That seems wrong to me

[dylanwulf]

Updated reproduction to use the latest template and apollo client version (3.3.19), issue is still there

[hwillson]

Thanks for this @dylanwulf - we'll take a closer look.

[dylanwulf]

@hwillson thank you for the response! sorry for my previous (now deleted) comment, it turned out to be a dumb mistake unrelated to this issue and has been taken care of. The original bug reproduction still stands though.

[dylanwulf]

Confirmed that #8422 fixes this, closing! Thank you so much for your help ❤️