Encapsulated resolvers to do not mesh properly

[bigman73]

Issue workflow progress

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• 1. The issue provides a reproduction available on Github, Stackblitz or CodeSandbox

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• 2. A failing test has been provided
• 3. A local solution has been provided
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---

Describe the bug

There are two GraphQL sources, books and animals. Both have a heartbeat query that returns a String. Both services function on their own, and return a valid heartbeat.
In .meshrc.yaml the services are wrapped twice, where the outer wrapper has the same name, platform.
The schema typedefs meshes/merges as expected. When running the heartbeat on the first encapsulated service it works as expected.

The second encapsulated heartbeat fails:

{
  "errors": [
    {
      "message": "Cannot return null for non-nullable field platformQuery.pets.",
      "path": [
        "platform",
        "pets"
      ]
    }
  ],
  "data": null
}

Changing the second encapsulation to a different name, such as platform2 resolves the problem, but it's not an acceptable solution.

To Reproduce
Steps to reproduce the behavior:

sources:
  - name: BooksService
    handler:
      graphql:
        endpoint: '{env.SERVICE1_URL}'
    transforms:
      - encapsulate:
          name: library
          applyTo:
            query: true
            mutation: true
            subscription: false
      - encapsulate:
          name: platform
          applyTo:
            query: true
            mutation: true
            subscription: false
  - name: AnimalsService
    handler:
      graphql:
        endpoint: '{env.SERVICE2_URL}'
    transforms:
      - encapsulate:
          name: pets
          applyTo:
            query: true
            mutation: true
            subscription: false
      - encapsulate:
          name: platform
          applyTo:
            query: true
            mutation: true
            subscription: false

Execute query:

query {
  platform {
    pets {
      heartbeat
    }
  }
}

Expected behavior

The expected behavior is that graphql mesh meshes the resolvers of encapsulated services, since they are not colliding or conflicting. Each encapsulated service resides under a different name (e.g. library or pets).

Environment:

• OS: MacOS 12.5.1, M1 Pro
• "@graphql-mesh/graphql": "^0.33.5",
• "@graphql-mesh/transform-encapsulate": "^0.4.4",
• NodeJS: v16.18.1

Additional context

I tried to globally encapsulate the entire schema. This does work for both heartbeats but it encapsulates the additional types and resolvers, not just the source underlying schemas, so it's not a viable solution.

[ardatan]

Could you share a reproduction on CodeSandbox or StackBlitz? Thanks!