Swift modelgen creates wrong decoding initializer with optional custom type in required array

[marcoboerner]

Describe the bug

When running npx ampx generate graphql-client-code --format modelgen --model-target swift on my Amplify Swift project, depending on the models defined in data/resource.ts the decoding initializer does not compile due to a Cannot assign value of type '[MyCustomType]?' to type '[MyCustomType?] error in Xcode.

Expected Behavior

myCustomTypes = try values.decode([MyCustomType?].self, forKey: .myCustomTypes) should be generated

Current Behavior

myCustomTypes = try? values.decode([MyCustomType].self, forKey: .myCustomTypes) is generated

Reproduction Steps

Define the following models in data/resource.ts:

// Custom types

MyCustomType: a.customType({
  context: a.string(),
}),

// Models

MyModel: a.model({
  context: a.string(),
  myCustomTypes: a.ref('MyCustomType').array().required(),
  myOtherModelId: a.id().required(),
  myOtherModel: a.belongsTo('MyOtherModel', 'myOtherModelId')
})
  .authorization(allow => [allow.owner()]),

MyOtherModel: a.model({
  context: a.string(),
  myModel: a.hasOne('MyModel', 'myOtherModelId')
})
  .authorization(allow => [allow.owner()]),

And run npx ampx generate graphql-client-code --format modelgen --model-target swift to create the models.

Possible Solution

No response

Additional Information/Context

When changing the custom type in the array to a non-optional, the decoding is done correctly.

// Custom types

MyCustomType: a.customType({
  context: a.string(),
}),

// Models

MyModel: a.model({
  context: a.string(),
  myCustomTypes: a.ref('MyCustomType').required().array().required(), // <-- changed !!!
  myOtherModelId: a.id().required(),
  myOtherModel: a.belongsTo('MyOtherModel', 'myOtherModelId')
})
  .authorization(allow => [allow.owner()]),

MyOtherModel: a.model({
  context: a.string(),
  myModel: a.hasOne('MyModel', 'myOtherModelId')
})
  .authorization(allow => [allow.owner()]),

CLI version used

aws-cli/2.17.56 Python/3.12.6 Darwin/24.1.0 source/arm64

Environment details (OS name and version, etc.)

macOS 15.1, Xcode 16.1 beta 2, swift-tools-version: 6.0, swiftLanguageModes v5

[tim-finnigan]

Thanks for reaching out. I think this was intended for an AWS Amplify repository, such as amplify-cli or amplify-swift.

This repository is for the AWS CLI — here is the command reference documentation: https://awscli.amazonaws.com/v2/documentation/api/latest/index.html

[marcoboerner]

@tim-finnigan thanks for the info! Will close this issue.

[github-actions]

This issue is now closed. Comments on closed issues are hard for our team to see.
If you need more assistance, please open a new issue that references this one.