Redundancy between mutators and defaultMutations?

[eric-burel]

Describe the bug
We have a function to get the document to update in default mutations, but also in the mutators:

• packages/graphql/server/resolvers/defaultMutationResolvers.ts (getMutationDocument)
• packages/graphql/server/resolvers/mutators.ts

Shouldn't we remove the one in the default mutation?

[eric-burel]

It leads to a bug where useUpdate({input: {id: "foo", data: {...}}}) doesn't work (when specifying id explicitely).

On the example of "update", I think we should do this:

• remove the check for the document presence in performMutationCheck => that's the responsbility of the mutator
• remove the call to "getMutationDocument" => that's the responsibility of the mutator as well to check the document existence
• keep passing either "selector" or "dataId" to the mutator in the mutation

The mutations are there: packages/graphql/server/resolvers/defaultMutationResolvers.ts
The mutator there: packages/graphql/server/resolvers/mutators.ts

The path is like this:
request > mutation > mutator > database

So in the MVC model, mutation is a Controller (it simply checks authorization, convert the input into a data selector, and that's it) and mutator a Model (it communicates more closely with the db, checking document existence and updating it).