Not working: Move array response to top of query from JSON rest API response (Transform, Replace Field, json-schema)

[D1no]

Hi everyone, for a hobby project I'm trying graphql-mesh with json-schema to turn a rest API into a GraphQL endpoint. Followed the documentation, but have some trouble. I want to move up the array response of the rest API.

Situation

I want to turn this

query MyQuery {
  sleep {    # <-- Get rid of this level
    sleep {
      start
      end
      score
    }
  }
}

schema {
  query: Query
}

type Query {
  sleep: Sleep_History
}

type Sleep_History {    //
  sleep: [Sleep_Entry]  //  <-- Get rid of this level
}                       //

type Sleep_Entry {
  start: DateTime
  end: DateTime
  score: Int
}

into this (directly returning the array of entries under the query):

query MyQuery {
  sleep {
    start
    end
    score
  }
}

schema {
  query: Query
}

type Query {
  sleep: [Sleep_Entry]
}

type Sleep_Entry {
  start: DateTime
  end: DateTime
  score: Int
}

Problem

I followed the example in the documentation, it builds and looks as I want it. But when I run the query, it just returns sleep: null

Example

Say my rest API returns the following:

{
    "sleep": [
        {
            "start": "2010-01-01T01:00:00+01:00",
            "end": "2011-01-01T01:00:00+01:00",
            "score": 123
        },
        {
            "start": "2012-01-01T01:00:00+01:00",
            "end": "2013-01-01T01:00:00+01:00",
            "score": 123
        },
        // (...)
    ]
}

The json schema I have created is this:

{
    "type": "object",
    "title": "Sleep History",
    "properties": {
        "sleep": {
            "title": "History",
            "type": "array",
            "items": [
                {
                    "type": "object",
                    "title": "Sleep Entry",
                    "properties": {
                        "start": {
                            "type": "string",
                            "format": "date-time"
                        },
                        "end": {
                            "type": "string",
                            "format": "date-time"
                        },
                        "score": {
                            "type": "number"
                        }
                    }
                }
            ]
        }
    }
}

The .meshrc.yaml looks like this (analog to the documentation):

sources:
  - name: SleepAPI
    handler:
      jsonSchema:
        baseUrl: https://api.polarbears.com/v1/
        operations:
          - type: Query
            field: sleep
            path: /sleep
            method: GET
            responseSchema: .json-schemas/polarbears/sleep.json

    transforms:                         # 
      - replace-field:                  # Analog from the
          replacements:                 # Documentation
            - from:                     #
                type: Query             # <- Schema Query
                field: sleep            #
              to:                       #
                type: Sleep_History     # <- Replace with
                field: sleep            #    Array of Entries
              scope: hoistValue         #    

Thank you for any guidance.

Edit: Made this more verbose so it can maybe help others who are searching for basic transforms on wrapping a json rest API into a GraphQL endpoint. I find graphql-mesh pretty enticing; but it's really hard to find resources. Or I just suck at using yaml in this mix of imperative programming and all this is obvious 🤷🏻‍♂️

Versions

Operating System: MacOS 
node: v16.13.1

"@graphql-mesh/cli": "^0.48.0",
"@graphql-mesh/json-schema": "^0.23.4",
"@graphql-mesh/transform-replace-field": "^0.3.8",
"graphql": "^15.8.0"

[santino]

Hi @D1no ,
your configuration looks correct and from what I can tell it should achieve what you're after.

Are you able to share a Codepen or repository with a reproduction of this issue, so we can investigate?

In the meantime, can you copy/paste your generated GraphQL schemas without the transform and with the transform?
I'd like to see how the transform is affecting the schema.

[D1no]

Edit: I posted this as an Issue now #3533

Thank you for the quick reply @santino. Sure, here you go:

As Codesandbox:
https://codesandbox.io/s/reproduction-graphql-mesh-json-api-transform-e0t4b?file=/.meshrc.yaml

The Reproduction Repository:
https://github.com/D1no/reproduction-graphql-mesh-json-api-transform

npm install
npm start

Schema: Before Transform

schema {
  query: Query
}

type Query {
  sleep: Sleep_History
}

type Sleep_History {
  sleep: [Sleep_Entry]
}

type Sleep_Entry {
  start: DateTime
  end: DateTime
  score: Float
}

"A date-time string at UTC, such as 2007-12-03T10:15:30Z, compliant with the `date-time` format outlined in section 5.6 of the RFC 3339 profile of the ISO 8601 standard for representation of dates and times using the Gregorian calendar."
scalar DateTime

Schema: After Transform

schema {
  query: Query
}

type Query {
  sleep: [Sleep_Entry]
}

type Sleep_Entry {
  start: DateTime
  end: DateTime
  score: Float
}

"A date-time string at UTC, such as 2007-12-03T10:15:30Z, compliant with the `date-time` format outlined in section 5.6 of the RFC 3339 profile of the ISO 8601 standard for representation of dates and times using the Gregorian calendar."
scalar DateTime

After transform, schema is as expected but the return is null

[santino]

Following up in #3533

I think you can mark this as answered since this has been done on the issue thread.

[D1no]

agreed