unexpected behavior of @default with non-string types

[josefaidt]

Before opening, please confirm:

• I have installed the latest version of the Amplify CLI (see above), and confirmed that the issue still persists.
• I have searched for duplicate or closed issues.
• I have read the guide for submitting bug reports.
• I have done my best to include a minimal, self-contained set of instructions for consistently reproducing the issue.
• I have removed any sensitive information from my code snippets and submission.

How did you install the Amplify CLI?

pnpm

If applicable, what version of Node.js are you using?

v16.13.2

Amplify CLI Version

7.6.25

What operating system are you using?

mac

Did you make any manual changes to the cloud resources managed by Amplify? Please describe the changes made.

no

Amplify Categories

api

Amplify Commands

Not applicable

Describe the bug

@default does not work for non-string types unless supplied default value is passed as a string. In the example below we are attempting to set default values based on the field type.

type Todo @model {
  someString: String @default(value: "my-default-string")
  someInt: Int @default(value: 42)
  someFloat: Float @default(value: 3.14)
  someBoolean: Boolean @default(value: true)
}

However this results in an error upon running amplify api gql-compile:

🛑 Schema validation failed.

Expected type String!, found 42.

GraphQL request:12:32
11 |   someString: String @default(value: "my-default-string")
12 |   someInt: Int @default(value: 42)
   |                                ^
13 |   someFloat: Float @default(value: 3.14)

Expected type String!, found 3.14.

GraphQL request:13:36
12 |   someInt: Int @default(value: 42)
13 |   someFloat: Float @default(value: 3.14)
   |                                    ^
14 |   someBoolean: Boolean @default(value: true)

Expected type String!, found true.

GraphQL request:14:40
13 |   someFloat: Float @default(value: 3.14)
14 |   someBoolean: Boolean @default(value: true)
   |                                        ^
15 | } 

After modifying the schema to pass default values as strings, we are then able to successfully compile the GraphQL schema and observe VTL templates are generated with the correct default values:

type Todo @model {
  someString: String @default(value: "my-default-string")
  someInt: Int @default(value: "42")
  someFloat: Float @default(value: "3.14")
  someBoolean: Boolean @default(value: "true")
}

and the resulting Mutation.createTodo.init.2.req.vtl for example

## [Start] Setting "someString" to default value of "my-default-string". **
$util.qr($context.args.input.put("someString", $util.defaultIfNull($ctx.args.input.someString, "my-default-string")))
## [End] Setting "someString" to default value of "my-default-string". **
## [Start] Setting "someInt" to default value of "42". **
$util.qr($context.args.input.put("someInt", $util.defaultIfNull($ctx.args.input.someInt, 42)))
## [End] Setting "someInt" to default value of "42". **
## [Start] Setting "someFloat" to default value of "3.14". **
$util.qr($context.args.input.put("someFloat", $util.defaultIfNull($ctx.args.input.someFloat, 3.14)))
## [End] Setting "someFloat" to default value of "3.14". **
## [Start] Setting "someBoolean" to default value of "true". **
$util.qr($context.args.input.put("someBoolean", $util.defaultIfNull($ctx.args.input.someBoolean, true)))
## [End] Setting "someBoolean" to default value of "true". **
{}

Expected behavior

Default value adheres to field type

type Todo @model {
  someString: String @default(value: "my-default-string")
  someInt: Int @default(value: 42)
  someFloat: Float @default(value: 3.14)
  someBoolean: Boolean @default(value: true)
}

Reproduction steps

1. amplify init -y
2. amplify add api > GraphQL > Blank schema
3. paste provided schema
4. amplify api gql-compile
5. observe error

GraphQL schema(s)

# Put schemas below this line

Log output

# Put your logs below this line

Additional information

https://docs.amplify.aws/cli/graphql/data-modeling/#assign-default-values-for-fields

[josefaidt]

NOTE: this is working as expected. add more examples to the docs for non-string types

[naingaungphyo]

So does it mean we always need to use string value whatever the type of the field is?

[naingaungphyo]

add more examples to the docs for non-string types

I can't see any docs update yet but I think we can't use non-string as default value regardless of the corresponding field type.

[naingaungphyo]

> The value parameter must be formatted as a string regardless of the corresponding field type.

I can confirm that it works for Int type with default value parameter as string.

[davaya]

Is there documentation for what string equivalents are allowed? (e.g., "nil" or JSON "null" or Python "None", IEEE 754 "NaN", "6.022E23", etc)

[hisham]

+1. Better documentation would have saved me some time here. Thanks!

Even Amazon Q gave me wrong info:

[github-actions]

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