graphql: single mutation or one mutation per type - graphql

Question

I have a GraphQL schema like this:
type User {
id: ID
name: String
email: String
addresses: [UserAddress]
}
type UserAddress {
id: ID
city: String
country: String
}
I always have doubts about how to make the best design for mutations. (I'm using apollo + prisma)
These are my options:
1) One single mutation
I need to create this mutation and input type:
input userAddressInput {
id: ID
city: String
country: String
}
mutation updateUser (
id: ID
name: String
email: String
addresses: UserAddressInput
): User
Then I execute mutations like this:
mutation updateUserData($id: ID, $name: String, $email: String) {
updateUser(id: $id, name: $name, email: $email) {
id
name
email
}
}
mutation updateUserAddress($id: ID, $userAddress: UserAddressInput) {
updateUser(id: $id, userAddress: $userAddress) {
id
addresses {
id
city
country
}
}
}
And resolvers like this:
Mutation: {
updateUser: (_, args) => {
if (args.name || args.email) {
// update model User by args.userData.id
}
if (args.userAddress) {
// update model UserAddress by args.userAddress.id
}
}
}
2) One mutation per type
I don't need to create any input type but I need two mutations:
mutation updateUser (
id: ID
name: String
email: String
): User
mutation updateUserAddress (
id: ID
city: String
country: String
): UserAddress
Then mutations like this:
mutation updateUser($id: ID, $name: String, $email: String) {
updateUser(id: $id, name: $name, email: $email) {
id
name
email
}
}
mutation updateUserAddress($id: ID, $city: String, $country: String) {
updateUserAddress(id: $id, city: $city, country: $country) {
id
city
country
}
}
And resolvers like this:
Mutation: {
updateUserAddress: (_, args) => {
// update model UserAddress by args.id
}
updateUser: (_, args) => {
// update model User by args.id
}
}
What is the best way to deal with such cases?

Answer 1

It depends what your use case is.
Does your GUI allow for update of a user's addresses without also updating the user info? If so you will likely need a separate mutation for updating only the addresses.
If you are allowing user and addresses to be edited and saved as one operation then individual mutations would require you to send multiple HTTP requests (one per mutation).
Do you need to update the user and addresses as an atomic transaction (i.e. all or nothing)? If so then you should use a single mutation.