Unify error behavior of client.mutate and update its type

[jerelmiller]

Closes #12455
Fixes #9065
Fixes #7167
Partially addresses #12427

Updates client.mutate to return a MutateResult type instead of a FetchResult. FetchResult is the raw response type we expect from the link chain. Because of this, we were not able to apply error unification to mutations since there is no error property on this type.

This change swaps errors for error and applies the same error unification behavior to mutations as was done to queries in #12457. Network errors are now subject to the errorPolicy and will resolve the mutation promise if the errorPolicy is not none.

This change also fixes a long-standing bug with useMutation where passing an onError callback would resolve the promise returned from the mutation when errorPolicy was none. These errors are now rejected to ensure the mutation behaves the same whether or not onError was provided.

[changeset-bot]

🦋 Changeset detected

Latest commit: e2c12e1

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

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[svc-apollo-docs]

⚠️ Docs preview not attached to branch

The preview was not built because the PR's base branch release-4.0 is not in the list of sources.

An Apollo team member can comment one of the following commands to dictate which branch to attach the preview to:

• !docs set-base-branch version-2.6
• !docs set-base-branch main

Build ID: 8e25f55327a8bb5901a48b8c

[pkg-pr-new]

npm i https://pkg.pr.new/@apollo/client@12475

commit: e2c12e1

[netlify]

✅ Deploy Preview for apollo-client-docs ready!

Name	Link
🔨 Latest commit	e2c12e1
🔍 Latest deploy log	https://app.netlify.com/sites/apollo-client-docs/deploys/67eaa8893e7e3f000896e17b
😎 Deploy Preview	https://deploy-preview-12475--apollo-client-docs.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[github-actions]

size-limit report 📦

Path	Size
import { ApolloClient, InMemoryCache, HttpLink } from "@apollo/client" (CJS)	41.2 KB (-0.06% 🔽)
import { ApolloClient, InMemoryCache, HttpLink } from "@apollo/client" (production) (CJS)	36.78 KB (+0.25% 🔺)
import { ApolloClient, InMemoryCache, HttpLink } from "@apollo/client"	31.87 KB (+0.12% 🔺)
import { ApolloClient, InMemoryCache, HttpLink } from "@apollo/client" (production)	26.89 KB (+0.13% 🔺)
import { ApolloProvider } from "@apollo/client/react"	5.17 KB (0%)
import { ApolloProvider } from "@apollo/client/react" (production)	960 B (0%)
import { useQuery } from "@apollo/client/react"	6.99 KB (0%)
import { useQuery } from "@apollo/client/react" (production)	2.76 KB (0%)
import { useLazyQuery } from "@apollo/client/react"	6.39 KB (0%)
import { useLazyQuery } from "@apollo/client/react" (production)	2.17 KB (0%)
import { useMutation } from "@apollo/client/react"	6.34 KB (-1.91% 🔽)
import { useMutation } from "@apollo/client/react" (production)	2.11 KB (-5.44% 🔽)
import { useSubscription } from "@apollo/client/react"	6.83 KB (0%)
import { useSubscription } from "@apollo/client/react" (production)	2.62 KB (0%)
import { useSuspenseQuery } from "@apollo/client/react"	8.21 KB (0%)
import { useSuspenseQuery } from "@apollo/client/react" (production)	4 KB (0%)
import { useBackgroundQuery } from "@apollo/client/react"	8.06 KB (0%)
import { useBackgroundQuery } from "@apollo/client/react" (production)	3.83 KB (0%)
import { useLoadableQuery } from "@apollo/client/react"	8.06 KB (0%)
import { useLoadableQuery } from "@apollo/client/react" (production)	3.87 KB (0%)
import { useReadQuery } from "@apollo/client/react"	5.83 KB (0%)
import { useReadQuery } from "@apollo/client/react" (production)	1.61 KB (0%)
import { useFragment } from "@apollo/client/react"	5.89 KB (0%)
import { useFragment } from "@apollo/client/react" (production)	1.66 KB (0%)

[phryneas]

Good change, let's get this in!