I am migrating from apollo-link-state to @apollo/client, how do I write default data to InMemoryCache of @apollo/client without using cache.writeData?

Question

I use react 16.13 and am currently migrating from apollo-client 2.x to @apollo/client 3.1.1. I removed a lot of dependency libraries from my packages.json because most of them are now directly importable from @apollo/client. Everything was going fine until I tossed a big rock named "removal of defaults" while migrating from apollo-link-state.

With @apollo/client 3.x, we import InMemoryCache from @apollo/client directly, which is fine. But the withClientState link is no longer existent and ApolloClient doesn't support default values for local cache. I could not find any guide covering this problem. There is one guide for Angular, but it advises to use cache.writeData to construct the cache. Only problem is, in v3.x of @apollo/client, InMemoryCache doesn't have a writeData method anymore. There is a modify method but it is also not straightforward to use, at least I was not able to make it work for this purpose.

I have a large "defaults" object:

export default {
  authentication: {
    __typename: 'authentication',
    auth: ''
  },
  UserInfo: {
    __typename: 'UserInfo',
    employee: {
      __typename: 'UserInfoEmployee',
      defaultShopId: '',
      id: '',
      email: '',
      image: {
      __typename: 'image',
      id: '',
      url: ''
    },
    firstName: '',
    lastName: '',
    manager: '',
    boss: ''
    },
    countryCode: '',
    chainId: ''
  },
  defaultShop: {
    __typename: 'defaultShop',
    id: '',
    name: '',
    timeZone: null
  },
  locale: {
    __typename: 'locale',
    locale: getBrowserLocale()
  },
  countries: {
    __typename: 'countries',
    data: []
  },
  Products: {
    __typename: 'Products',
    guid: 0,
    ProductTypes: {
      __typename: 'ProductTypes',
      TypeNumber: 0,
      type: ''
    },
    legacyConfiguration: false,
    version: '1.0.0'
  },
  location: {
    __typename: 'location',
    pathname: '',
    search: '',
    hash: null,
    action: '',
    key: null,
    isQueryActive: false,
    query: null
  }
}

How should I write these default data into InMemoryCache without using cache.writeData?

Answer 1

Use writeQuery instead. I believe in v3 they moved towards using a common way for setting a default state.

Official docs

    const query = gql`
        query {
            authentication @client {
                id
                __typename
            }
            ...
        }`
    cache.writeQuery({
        query,
        data: {
            authentication: {
                __typename: 'authentication'
               ...
        }
    })