useMutation doesn't roll back optimistic cache.evict

Successful rollback

When I call this mutation, the following happens:

1. update is run with optimisticResponse, and an item is removed from the list
2. error is received from the server
3. the changes made in update are rolled back: the item is added back to the list

  const [removeReview] = useMutation(REMOVE_REVIEW_MUTATION, {
    update: (cache) => {
      const { reviews } = cache.readQuery({ query: REVIEWS_QUERY })
      cache.writeQuery({
        query: REVIEWS_QUERY,
        data: { reviews: reviews.filter((review) => review.id !== id) },
      })
    },
  })

...

    removeReview({
      variables: { id },
      optimisticResponse: {
        removeReview: true,
      },
    }).catch((e) => {
      if (find(e.graphQLErrors, { message: 'unauthorized' })) {
        alert('👮‍♀️✋ You can only delete your own reviews!')
      }
    })

Failing rollback

When the mutation update uses cache.evict instead of cache.writeQuery, step 3 does not occur.

const [removeReview] = useMutation(REMOVE_REVIEW_MUTATION, {
  update: (cache) => cache.evict({ id: cache.identify(review) })
})

https://github.com/GraphQLGuide/guide/blob/repro-rollback-fail/src/components/Review.js#L132-L141

Versions

System: OS: macOS 10.15.7 Binaries: Node: 10.22.0 - ~/.nvm/versions/node/v10.22.0/bin/node Yarn: 1.22.4 - ~/gh/guide/node_modules/.bin/yarn npm: 6.14.6 - ~/.nvm/versions/node/v10.22.0/bin/npm Browsers: Chrome: 86.0.4240.193 Safari: 14.0 npmPackages: @apollo/client: 3.1.3 => 3.2.5 apollo: ^2.30.2 => 2.30.2 apollo-cache-persist: 0.1.1 => 0.1.1 apollo-link-rest: 0.8.0-beta.0 => 0.8.0-beta.0 npmGlobalPackages: apollo: 2.30.2

[benjamn]

@lorensr @brainkim @Risbot @gmathieu @3nvi I did some more thinking, and I believe I’ve found a way to solve the original problem without passing any additional options: #8829

This is good news, because the same update function typically runs for both the optimistic update and the final non-optimistic update, so it would be tricky to handle the hypothetical optimistic: true option in the non-optimistic case, even if it seemed to solve the problem in the optimistic case.

[gmathieu]

Just ran into this today using v3.3.20. An optimistic flag would be really helpful!