DataStore cannot receive mutation updates made from Android, Amplify Studio

[HuiSF]

Describe the bug

In an App created using amplify-ios, or amplify-flutter (iOS platform), DataStore cannot receive mutation updates made from Android, Amplify Studio content management interface that are running with the same backend.

Related issues:

https://github.com/aws-amplify/amplify-flutter/issues/663 https://github.com/aws-amplify/amplify-android/issues/995

Condition: when model relationship is involved, and selection set is incompatible cross amplify libraries.

In iOS device, DataStore subscription receives event but the event actually is an error, e.g.

// Create a Post in Amplify Studio
// Subscription error occurred in amplify-ios backed App
{
  "id": "2FD9A5DC-0721-4F08-AFA5-A63099436BDB",
  "type": "data",
  "payload": {
    "data": {
      "onCreatePost": {
        "id": "d8ae7b09-b0b8-4a86-8095-42db434eae88",
        "createdAt": "2022-02-23T18:31:55.785Z",
        "rating": 10,
        "title": "Post from Studio",
        "updatedAt": "2022-02-23T18:31:55.785Z",
        "blog": null,
        "__typename": "Post",
        "_version": 1,
        "_deleted": null,
        "_lastChangedAt": 1645641115815
      }
    },
    "errors": [
      {
        "message": "Cannot return null for non-nullable type: 'AWSDateTime' within parent 'Blog' (/onCreatePost/blog/createdAt)",
        "path": ["onCreatePost", "blog", "createdAt"]
      },
      {
        "message": "Cannot return null for non-nullable type: 'String' within parent 'Blog' (/onCreatePost/blog/name)",
        "path": ["onCreatePost", "blog", "name"]
      },
      {
        "message": "Cannot return null for non-nullable type: 'AWSDateTime' within parent 'Blog' (/onCreatePost/blog/updatedAt)",
        "path": ["onCreatePost", "blog", "updatedAt"]
      },
      {
        "message": "Cannot return null for non-nullable type: 'Int' within parent 'Blog' (/onCreatePost/blog/_version)",
        "path": ["onCreatePost", "blog", "_version"]
      },
      {
        "message": "Cannot return null for non-nullable type: 'AWSTimestamp' within parent 'Blog' (/onCreatePost/blog/_lastChangedAt)",
        "path": ["onCreatePost", "blog", "_lastChangedAt"]
      }
    ]
  }
}

// Create a Post in amplify-android backed App
// Subscription error occurred in amplify-ios backed App
{
  "id": "2FD9A5DC-0721-4F08-AFA5-A63099436BDB",
  "type": "data",
  "payload": {
    "data": {
      "onCreatePost": {
        "id": "114d4f13-972b-4bfc-ae30-4eb614a8c7df",
        "createdAt": "2022-02-23T18:47:45.421Z",
        "rating": 10,
        "title": "Test Post",
        "updatedAt": "2022-02-23T18:47:45.421Z",
        "blog": null,
        "__typename": "Post",
        "_version": 1,
        "_deleted": null,
        "_lastChangedAt": 1645642065440
      }
    },
    "errors": [
      {
        "message": "Cannot return null for non-nullable type: 'AWSDateTime' within parent 'Blog' (/onCreatePost/blog/createdAt)",
        "path": ["onCreatePost", "blog", "createdAt"]
      },
      {
        "message": "Cannot return null for non-nullable type: 'String' within parent 'Blog' (/onCreatePost/blog/name)",
        "path": ["onCreatePost", "blog", "name"]
      },
      {
        "message": "Cannot return null for non-nullable type: 'AWSDateTime' within parent 'Blog' (/onCreatePost/blog/updatedAt)",
        "path": ["onCreatePost", "blog", "updatedAt"]
      },
      {
        "message": "Cannot return null for non-nullable type: 'Int' within parent 'Blog' (/onCreatePost/blog/_version)",
        "path": ["onCreatePost", "blog", "_version"]
      },
      {
        "message": "Cannot return null for non-nullable type: 'AWSTimestamp' within parent 'Blog' (/onCreatePost/blog/_lastChangedAt)",
        "path": ["onCreatePost", "blog", "_lastChangedAt"]
      }
    ]
  }
}

Steps To Reproduce

Steps to reproduce the behavior:
1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior

Mutation updates should work cross amplify libraries.

Amplify Framework Version

1.22.0

Amplify Categories

DataStore

Dependency manager

Swift PM

Swift version

5

CLI version

The latest

Xcode version

13.2.1

Relevant log output

No response

Is this a regression?

No

Regression additional context

No response

Device

iPhone 13 simulators

iOS Version

iOS 15

Specific to simulators

No response

Additional context

No response