Generated code seems to be wrong when using definitions

[wnkz]

TLDR

Generated code in models.py seems to be wrongfully using definition's name as a key instead of the property referencing the definition.

---

If I try to implement a Tags property defined ike this one Sample: Kinesis Stream Integration

Simplified example, a resource with Tags property defined like this, generates the following documentation and code.

foo-bar-baz.json

{
    "typeName": "FOO::Bar::Baz",
    "definitions": {
        "Tag": {
            "properties": {
                "Key": {
                    "description": "The key name of the tag.",
                    "type": "string"
                },
                "Value": {
                    "description": "The value for the tag.",
                    "type": "string"
                }
            }
        }
    },
    "properties": {
        "Tags": {
            "type": "array",
            "uniqueItems": true,
            "items": {
                "$ref": "#/definitions/Tag"
            },
            "maximum": 50
        }
    }
    ...
}

README.md

# FOO::Bar::Baz

## Properties

#### Tags

An arbitrary set of tags (key-value pairs) for this S3 bucket.

_Required_: No

_Type_: List of <a href="tag.md">Tag</a>

_Update requires_: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

tag.md

# FOO::Bar::Baz Tag

## Syntax

To declare this entity in your AWS CloudFormation template, use the following syntax:

### JSON

<pre>
{
    "<a href="#key" title="Key">Key</a>" : <i>String</i>,
    "<a href="#value" title="Value">Value</a>" : <i>String</i>
}
</pre>

### YAML

<pre>
<a href="#key" title="Key">Key</a>: <i>String</i>
<a href="#value" title="Value">Value</a>: <i>String</i>
</pre>

## Properties

#### Key

The key name of the tag.

_Required_: No

_Type_: String

_Update requires_: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

#### Value

The value for the tag.

_Required_: No

_Type_: String

_Update requires_: [No interruption](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-no-interrupt)

models.py

@dataclass
class ResourceModel(BaseModel):
    Tags: Optional[Sequence["_Tag"]]

    @classmethod
    def _deserialize(
        cls: Type["_ResourceModel"],
        json_data: Optional[Mapping[str, Any]],
    ) -> Optional["_ResourceModel"]:
        if not json_data:
            return None
        dataclasses = {n: o for n, o in getmembers(sys.modules[__name__]) if isclass(o)}
        recast_object(cls, json_data, dataclasses)
        return cls(
            Tags=deserialize_list(json_data.get("Tag"), Tag),
        )

@dataclass
class Tag(BaseModel):
    Key: Optional[str]
    Value: Optional[str]

    @classmethod
    def _deserialize(
        cls: Type["_Tag"],
        json_data: Optional[Mapping[str, Any]],
    ) -> Optional["_Tag"]:
        if not json_data:
            return None
        return cls(
            Key=json_data.get("Key"),
            Value=json_data.get("Value"),
        )

The problem here is that ResourceModel class tries to fetch Tags from JSON using the Tag key instead of Tags

With the following desiredResourceState

{
    "credentials": {
        "accessKeyId": "",
        "secretAccessKey": "",
        "sessionToken": ""
    },
    "action": "CREATE",
    "request": {
        "clientRequestToken": "4b90a7e4-b790-456b-a937-0cfdfa211dfe",
        "desiredResourceState": {
            "Tags": [
                {
                    "Key": "FOO",
                    "Value": "BAR"
                }
            ]
        },
        "logicalResourceIdentifier": "MyResource"
    },
    "callbackContext": null
}

We end up with a resource model looking like this

ResourceModel(Tags=None)

instead of

ResourceModel(Tags=[Tag(Key='FOO', Value='BAR')])

Because of

Tags=deserialize_list(json_data.get("Tag"), Tag),