Amplify-cli: in single schema a second query and mutation section is ignored by schema compiler

[ryanhollander]

Describe the bug
in single schema a second query and mutation section is ignored by schema compiler.

To Reproduce

create schema.graphql:

type A@model(queries: null, mutations: null) { id: ID!, name: String }
type B@model(queries: null, mutations: null) { id: ID!, name: String }
type Mutation {
createA(id: ID!): A
}
type Query {
getA(id: ID!): A
}
type Mutation {
createB(id: ID!): B
}

===
Expected behavior
Since this isn't valid the compiler should throw an error, instead it just ignores the extra entries. It would be better if it merged them, but I think the correct behavior is to throw an error so the programmer can correct the file.

Thank You.

[mikeparisstuff]

@ryanhollander Thanks for the comment. I tend to agree that compilation should fail if you try to define two types with the same name (e.g. how you define two types named Mutation). You can get the behavior you want by using the extend keywork for the second Mutation type.

type Mutation {
  createA: String
}
extend type Mutation {
  createB: String
}

I have made a note of this and we will include adding the extra validation to the backlog.

[ryanhollander]

Sounds good thanks @mikeparisstuff !

[kftsehk]

There maybe an implementation detail still not being clarified, it looks like the type Mutation in alphabetically ordered first file should have type Mutation and other should have extend type Mutation for it to work.

OK
schema/a.graphql

type A {
  id: ID!
}

type Mutation {
  createA: A
}

schema/b.graphql

type B {
  id: ID!
}

extend type Mutation {
  createB: B
}

FAILED

schema/a.graphql

type A {
  id: ID!
}

extend type Mutation {
  createA: A
}

schema/b.graphql

type B {
  id: ID!
}

type Mutation {
  createB: B
}

Failed with

× An error occurred when pushing the resources to the cloud

Type kind "ObjectTypeExtension" not supported.

Update:
And for case of "extend type Mutation createA" + "extend type Mutation createB" the error message is different from previous failed case.

Cannot extend non-existant type 'Mutation'.

[benmj]

For those arriving at this page, please take a look at the linked #2596 before you attempt to use extend type Mutation -- you _will not_ get generated cloud formation templates and resolvers from your extended, additional Mutations/Queries.