Throw an error if the link chain completes without emitting a value

[jerelmiller]

Closes #12482

Throws an error if a query or mutation does not emit a value before the link chain completes. This is usually a bug in the user's link chain and can have unintended consequences. By throwing, this makes the issue more visible and lets us clean up some areas of the codebase that would otherwise not be able to handle this situation.

This also addresses the issue where issuing a query with a standby fetch policy would throw an EmptyError and instead will resolve the query with data: undefined.

[changeset-bot]

🦋 Changeset detected

Latest commit: 9be41f9

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@apollo/client	Major

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[svc-apollo-docs]

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Build ID: 56a402c94556cd08486afd72

[pkg-pr-new]

npm i https://pkg.pr.new/@apollo/client@12485

commit: 9be41f9

[jerelmiller]

I didn't add a changeset for this change since this was introduced with the RxJS switchover. I'd be happy to add one though if we'd like to point this out for the alpha release.

[jerelmiller]

Every area of the codebase that used fetchQuery converted the result to a QueryResult, so I refactored it to transform the value here instead.

[jerelmiller]

Nice to get rid of these todos 👍

[jerelmiller]

This was here to guard against the link chain completing without emitting a value. Now that it results in an error condition, this check is no longer needed.

[jerelmiller]

This TODO type felt great to get rid of 🙂

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[github-actions]

size-limit report 📦

Path	Size
import { ApolloClient, InMemoryCache, HttpLink } from "@apollo/client" (CJS)	41.59 KB (+0.39% 🔺)
import { ApolloClient, InMemoryCache, HttpLink } from "@apollo/client" (production) (CJS)	36.94 KB (+0.02% 🔺)
import { ApolloClient, InMemoryCache, HttpLink } from "@apollo/client"	32.11 KB (+0.29% 🔺)
import { ApolloClient, InMemoryCache, HttpLink } from "@apollo/client" (production)	27.03 KB (+0.31% 🔺)
import { ApolloProvider } from "@apollo/client/react"	5.26 KB (+1.13% 🔺)
import { ApolloProvider } from "@apollo/client/react" (production)	964 B (0%)
import { useQuery } from "@apollo/client/react"	7.11 KB (+0.99% 🔺)
import { useQuery } from "@apollo/client/react" (production)	2.76 KB (0%)
import { useLazyQuery } from "@apollo/client/react"	6.48 KB (+0.87% 🔺)
import { useLazyQuery } from "@apollo/client/react" (production)	2.16 KB (0%)
import { useMutation } from "@apollo/client/react"	6.45 KB (+0.97% 🔺)
import { useMutation } from "@apollo/client/react" (production)	2.1 KB (0%)
import { useSubscription } from "@apollo/client/react"	6.74 KB (+0.9% 🔺)
import { useSubscription } from "@apollo/client/react" (production)	2.41 KB (0%)
import { useSuspenseQuery } from "@apollo/client/react"	8.33 KB (+1.02% 🔺)
import { useSuspenseQuery } from "@apollo/client/react" (production)	4.01 KB (0%)
import { useBackgroundQuery } from "@apollo/client/react"	8.15 KB (+0.84% 🔺)
import { useBackgroundQuery } from "@apollo/client/react" (production)	3.83 KB (0%)
import { useLoadableQuery } from "@apollo/client/react"	8.19 KB (+1% 🔺)
import { useLoadableQuery } from "@apollo/client/react" (production)	3.87 KB (0%)
import { useReadQuery } from "@apollo/client/react"	5.94 KB (+1.14% 🔺)
import { useReadQuery } from "@apollo/client/react" (production)	1.61 KB (0%)
import { useFragment } from "@apollo/client/react"	5.98 KB (+0.91% 🔺)
import { useFragment } from "@apollo/client/react" (production)	1.66 KB (0%)