Skip in React useQuery is not respected and onCompleted is behaving erratically in response

Intended outcome:

I’m trying to use skip in useQuery as a way to avoid getting errors from the GraphQL for variables that are already known to be wrong. If I understood the docs correctly, network requests should only be made if skip === true and onCompleted should only be called after a successful network request.

Actual outcome:

Even when skip is set to true, onCompleted seems to get called and the network panel of the browser dev tools show that there has indeed been a request. Also, if skip is true at the start, onCompleted still is called once althought at this time there is no network activity.

How to reproduce the issue:

I have created a short demo repository here. It is an app that lists all continents using https://countries.trevorblades.com/ as a list of buttons. A click on the a button triggers the retrieval of this specific continent in a separate component. A continent with an invalid code (undefined) has been manually added to this list. The Continent component accepts either a string or undefined as continent code. This is for demonstration purposes, in this particular case rendering of the Continent component could otherwise be skipped altogether in case the code is a known invalid value.

After the demo has been loaded (best with Open In New Window to be able to see the network tab), please notice that onCompleted has already been called once even though no continent has been selected yet. To demonstrate, I suggest the following clicks:

1. Button Asia: everything works as expected, AS is added to the list of codes by onCompleted
2. Button North America: all ok, NA is added
3. Button Europe: Still ok
4. Button [Code undefined]: Although skip is now true, a network request has been made and onCompleted has been called. The result of the network request was 400 - Bad request but onError has not been called
5. Button Europe: The query is called and the continent is set to Europe but onCompleted doesn’t seem to have been called
6. Button North America: NA is added to the list, the selected continent is correct, everything is OK again until [Code undefined] is pressed again, then it goes back to the behavior described after Point 4

Versions

@apollo/client: 3.0.0-RC.9
graphql: 15.1.0
react: 16.13.1
react-scripts: 3.4.1

I hope this reproduction is OK, I’m not sure how to better describe the problem. Kind regards, Daniel

[yngwi]

As far as I can tell fixed in @apollo/client: 3.0.1

[yngwi]

Still the same behavoiur with @apollo/client: 3.0.0 final.