Found #client directives in a query but no ApolloClient resolvers were specified - apollo

Question

OS: Windows 10 Pro
apollo-client: 2.6.3
apollo-boost: 0.1.16
Can anyone explain why I'm getting the following error message?:
Found #client directives in a query but no ApolloClient resolvers were
specified. This means ApolloClient local resolver handling has been
disabled, and #client directives will be passed through to your link
chain.
when I've defined my ApolloClient as follows:
return new ApolloClient({
uri: process.env.NODE_ENV === 'development' ? endpoint : prodEndpoint,
request: operation => {
operation.setContext({
fetchOptions: {
credentials: 'include',
},
headers: { cookie: headers && headers.cookie },
});
},
// local data
clientState: {
resolvers: {
Mutation: {
toggleCart(_, variables, { cache }) {
// Read the cartOpen value from the cache
const { cartOpen } = cache.readQuery({
query: LOCAL_STATE_QUERY,
});
// Write the cart State to the opposite
const data = {
data: { cartOpen: !cartOpen },
};
cache.writeData(data);
return data;
},
},
},
defaults: {
cartOpen: false,
},
},
});

Answer 1

From the docs:
If you're interested in integrating local state handling capabilities with Apollo Client < 2.5, please refer to our (now deprecated) apollo-link-state project. As of Apollo Client 2.5, local state handling is baked into the core, which means it is no longer necessary to use apollo-link-state
The clientState config option was only used with apollo-link-state. You need to add the resolvers directly to the config as shown in the docs:
new ApolloClient({
uri: '/graphql',
resolvers: { ... },
})
Also note that there is no defaults option anymore -- the cache should be initialized by calling writeData directly on the cache instance (see here).
I would suggest going through the latest docs and avoiding any examples from external sources (like existing repos or tutorials) since these may be outdated.
Note: As of version 3.0, writeData was removed in favor of writeFragment and writeQuery.