Schema validation failed. There can be only one type named "EventInvocationResponse"

[v-bilyavskiy]

Environment information

System:
  OS: macOS 15.2
  CPU: (8) arm64 Apple M1
  Memory: 108.17 MB / 16.00 GB
  Shell: /bin/zsh
Binaries:
  Node: 22.11.0 - ~/.nvm/versions/node/v22.11.0/bin/node
  Yarn: undefined - undefined
  npm: 10.9.0 - ~/.nvm/versions/node/v22.11.0/bin/npm
  pnpm: 9.15.2 - ~/Library/pnpm/pnpm
NPM Packages:
  @aws-amplify/auth-construct: Not Found
  @aws-amplify/backend: 1.11.0
  @aws-amplify/backend-auth: 1.4.2
  @aws-amplify/backend-cli: 1.4.5
  @aws-amplify/backend-data: Not Found
  @aws-amplify/backend-deployer: Not Found
  @aws-amplify/backend-function: 1.10.0
  @aws-amplify/backend-output-schemas: Not Found
  @aws-amplify/backend-output-storage: Not Found
  @aws-amplify/backend-secret: Not Found
  @aws-amplify/backend-storage: 1.2.4
  @aws-amplify/cli-core: Not Found
  @aws-amplify/client-config: Not Found
  @aws-amplify/deployed-backend-client: Not Found
  @aws-amplify/form-generator: Not Found
  @aws-amplify/model-generator: Not Found
  @aws-amplify/platform-core: 1.4.0
  @aws-amplify/plugin-types: 1.6.0
  @aws-amplify/sandbox: Not Found
  @aws-amplify/schema-generator: Not Found
  aws-amplify: 6.11.0
  aws-cdk: 2.173.0
  aws-cdk-lib: 2.173.0
  typescript: 5.7.2
No AWS environment variables
No CDK environment variables

Describe the bug

When using a.combine() and having a.handler.function(...).async() in each scheme, the following error:

cause: SchemaValidationError: Schema validation failed.
  
  There can be only one type named "EventInvocationResponse".
  
  GraphQL request:5:6
  4 |
  5 | type EventInvocationResponse @aws_cognito_user_pools {
    |      ^
  6 |   success: Boolean!
  
  GraphQL request:98:6
  97 |
  98 | type EventInvocationResponse @aws_cognito_user_pools {
     |      ^
  99 |   success: Boolean!
  
  Field "EventInvocationResponse.success" can only be defined once.
  
  GraphQL request:6:3
  5 | type EventInvocationResponse @aws_cognito_user_pools {
  6 |   success: Boolean!
    |   ^
  7 | }
  
  GraphQL request:99:3
   98 | type EventInvocationResponse @aws_cognito_user_pools {
   99 |   success: Boolean!
      |   ^
  100 | }
  
  The directive "@aws_cognito_user_pools" can only be used once at this location.
  
  GraphQL request:5:30
  4 |
  5 | type EventInvocationResponse @aws_cognito_user_pools {
    |                              ^
  6 |   success: Boolean!
  
  GraphQL request:98:30
  97 |
  98 | type EventInvocationResponse @aws_cognito_user_pools {
     |                              ^
  99 |   success: Boolean!

In my opinion, the problem is that for each of the schemes a type with the same name is added, and when merging the schemas, duplicates arise.

https://github.com/aws-amplify/amplify-data/blob/2394f64dc37eeda0f6a48876ec8d22709662c2a7/packages/data-schema/src/SchemaProcessor.ts#L1345-L1362
https://github.com/aws-amplify/amplify-data/blob/2394f64dc37eeda0f6a48876ec8d22709662c2a7/packages/data-schema/src/CustomOperation.ts#L361-L371

Reproduction steps

const schema = a.combine([
  a.schema({
    mutation1: a
      .mutation()
      .arguments({
        ...
      })
      .handler(
        a.handler.function(handler1).async(),
      )
      .authorization(allow => [
        ...
      ]),
  }),
  a.schema({
    mutation2: a
      .mutation()
      .arguments({
        ...
      })
      .handler(
        a.handler.function(handler2).async(),
      )
      .authorization(allow => [
        ...
      ]),
  }),
])

export const data = defineData({
  schema,
})

[ykethan]

Hey,👋 thanks for raising this! I'm going to transfer this over to our API repository for better assistance 🙂