Cache merge is producing extra network call

[dskelton-r7]

Intended outcome:

Given two components, Component A and Component B that run the same query, with Component B requesting a little more from the graph.

When defining a custom merge function and using network-only on both components useQuery calls.

There should only be 2 network requests made. 1 for Component A and 1 for B.

Actual outcome:
The request for Component A is made again after component B finishes.

How to reproduce the issue:
Using apollo client v3.2.0
https://codesandbox.io/s/awesome-gagarin-4rdyp?file=/src/App.js

Not happening using apollo client v2
https://codesandbox.io/s/nice-goodall-odfcy?file=/src/App.js

Versions
@apollo/[email protected]

[dskelton-r7]

Think I figured this one, the fix is to add empty keyfields to address

cache: new InMemoryCache({
    typePolicies: {
      Address: {
        keyFields: []
      },
      User: {
        fields: {
          address: {
            merge: true
          }
        }
      }
    }
  })

[benjamn]

@dskelton-r7 Thanks for answering your own question!

Since we're talking about an Address, I suspect you want keyFields: false (together with merge: true for User.address). The keyFields: [] configuration means that there's only ever one Address object in your whole application (a singleton), whereas keyFields: false means the Address will be embedded in its parent object (so you can have different addresses for different Users).

[dskelton-r7]

@benjamn Thanks for the response. That makes sense, so I updated the example with keyFields: false and it's back to the original issue. There is 3 requests being made, In my application I need fetch-only for some calls which is why they are added here.

https://codesandbox.io/s/epic-stallman-jvw7q?file=/src/App.js

[dskelton-r7]

@benjamn I also just noticed this issue that seems similar in nature #6307
So I downgraded to @apollo/[email protected] and its not longer happening. Here is a reproduction of that.

Only 2 requests are being made here
https://codesandbox.io/s/infallible-gagarin-u32cz?file=/src/App.js

[hwillson]

Let us know if this is still a concern with @apollo/client@latest - thanks!