apollo-client: useMutation onCompleted executed when errors present

Intended outcome:

I have an onCompleted callback defined on the options of useMutation. I only want onCompleted to execute when no errors are present; so, I’ve set defaultOptions: { query: { errorPolicy: 'all' }, mutate: { errorPolicy: 'all' } } on the ApolloClient.

This is the expected functionality that is described on the docs

Actual outcome:

When a GraphqlError occurs, the onCompleted function is still executed with null data.

How to reproduce the issue:

This is the gist of our setup. I’m working on reproducing the issue on a small app as well, and will post the links on here once that is up and running.

...

const client = new ApolloClient({
  link: ApolloLink.from([
    onError(({ operation, forward, response }) => {
      // Do stuff to handle errors

      forward(operation);
    }),
    new HttpLink({
      uri: `http://localhost:3000/api/graphql`,
      credentials: 'include'
    })
  ]),
  cache: new InMemoryCache(),
  defaultOptions: {
    query: { errorPolicy: 'all' },
    mutate: { errorPolicy: 'all' }
  }
});

...

const rootElement = document.getElementById('root');

ReactDOM.render(
  <React.StrictMode>
    <ApolloProvider client={client}>
      <App />
    </ApolloProvider>
  </React.StrictMode>,

  rootElement
);

...

const MyComponent = () => {
  const [mutation, { loading, error }] = useMutation(
    GQL_MUTATION,
    {
      onCompleted: (data) => {
        console.log('onCompleted executed with:');
        console.log(data);
      }
    }
  );

  return (
    <>
      <div>{JSON.stringify(error)}</div>
      <button
        disabled={loading}
        onClick={() => mutation()}
      >
        Execute Mutation
      </button>
    </>
  );
};

Versions

"@apollo/client": "^3.5.6"

System:
    OS: macOS 11.6.4
  Binaries:
    Node: 16.13.1 - ~/.nvm/versions/node/v16.13.1/bin/node
    Yarn: 1.22.17 - /usr/local/bin/yarn
    npm: 8.1.2 - ~/.nvm/versions/node/v16.13.1/bin/npm
  Browsers:
    Chrome: 99.0.4844.51
    Safari: 15.3