Query Functionality with `onCompleted` is broken in v3.0.0 release (CodeSandbox repro)

[3nvi]

Some core lazy querying functionality through useLazyQuery seems a bit off.

Specifically, when a lazy query (through a useLazyQuery hook) returns an error, then Apollo seems to start endlessly querying the server. The same thing happens if you give it a fetchPolicy of network-only (or anything that doesn't search the cache first).

Related: apollographql/react-apollo#4044

At the same time, if the lazy query function (returned by useLazyQuery) gets called more than 1 times, then no callbacks are fired. The onCompleted doesn't fire again. The onCompleted fires on the 1st successful run of the "query" function and then consecutive invocations of the lazy query function, don't trigger onCompleted callback (they should, since you can't have conditional business logic based on whether the data is cached or not!)

Related: apollographql/react-apollo#4000

Funnily enough, using client.query() works fine. All this used to work perfectly during the beta (I think I've verified that something occurred after @apollo/client@v3.0.0-beta.43), but now it doesn't.

UPDATE: I've added a codesandbox that reproduces it

Intended outcome:

• Lazy query errors shouldn't trigger endless API querying
• A network-only fetch policy shouldn't trigger endless API querying on a lazy query
• onCompleted should fire every time a lazy query gets successfully executed

Actual outcome:

• Lazy query errors & network-only fetch policy start an endless loop of requests
• onCompeted gets fired at most once regardless of the number of invocations

How to reproduce the issue:

• Take a lazy query and change the fetchPolicy to network-only or force an API error on a lazy query
• Click a button that triggers a lazy query multiple time, while observing the number of invocations of the onCompleted callback.

Versions
System:
OS: macOS 10.15.2
Binaries:
Node: 12.18.0 - /usr/local/bin/node
Yarn: 1.19.0 - /usr/local/bin/yarn
npm: 6.14.4 - /usr/local/bin/npm
Browsers:
Chrome: 83.0.4103.116
Firefox: 72.0.2
Safari: 13.0.4
npmPackages:
@apollo/client: ^3.0.2 => 3.0.2
apollo-link-error: ^1.1.12 => 1.1.13

[3nvi]

@benjamn Take a look here and observe the console

https://codesandbox.io/s/apollo-reference-equality-1exes?file=/src/App.js

While fetchPolicy is network-only React re-renders endlessly. If you make it cache-first things are ok again. Same thing would happen if the query errored.

Also observe how the ON COMPLETED text gets only logged once regardless of how many times the query finishes successfully

[3nvi]

I noticed that even if I change the variables after one query execution, the query automatically executes and fires its onCompleted (although it's lazy, so it shouldn't).

Related to apollographql/react-apollo#3729

In general, this seems like a bug that may be unrelated to lazy querying, but I feel it's something on the "core" functionality of querying since it manifests in many different ways

[kainanaina]

I'm using 3.0.0-beta.43 since February and everything worked there just fine. Tried an upgrade to stable v3 and encountered this issue.

[orrybaram]

I've noticed that this is also happening with a regular useQuery hook when an onCompleted function is specified (even if its a noop) and the fetchPolicy is set to anything except cache-first or cache-only

[3nvi]

I've noticed that this is also happening with a regular useQuery hook when an onCompleted function is specified (even if its a noop) and the fetchPolicy is set to anything except cache-first or cache-only

Yeah I also mentioned that I feel that this is not necessarily tied only to lazy queries. Will update description

[mfgredo]

Same problem. Endless request loop when using onCompleted in one of my applications after upgrading. Might go back to apollo-boost for now.

[hwillson]

This issue was fixed in #6588, and will be coming in @apollo/client@3.1.0 very soon.

[benjamn]

Heads up: we're not quite ready to publish @apollo/client@3.1.0 yet, but I've published an @apollo/client@3.1.0-pre.0 release that includes #6588, if you want to try that in the meantime. 🙏

Update: thanks to @3nvi's reproduction, I can confirm the fix: https://codesandbox.io/s/apollo-reference-equality-t0ttx