[NEST JS - TYPESCRIPT] nullable field not generated

Hey Swagger code gen team 🥷

📔 Description

I'm currently working on a monorepo nest js / angular app.
We use nx lib to create a reusable lib to provide frontend model according to backend type defintion.
So we decide to use swagger codegen to generate typescript model and serve that to our frontend
➡️ This working as excepted (good job to the team for the great work 🙌 )

For some reason, we need to use a nullable field.
So i just follow the documentation and i have this piece of code :

@ApiProperty({
    type: MyType,
    nullable: true,
})
MyNullableField!: MyType | null;

My class definition

but when i try generate my code with the codegen command, Swagger generated

Excepted code

MyNullableField: myType | null;

the code wanted by the generation

Swagger generated code

MyNullableField: myType;

generated code by swagger

🔢 Swagger-codegen version

I use swagger over Brew (im using Macos)

// mac version
Mac intel 2019
Mac OS Monterey
Version 12.5.1

// brew version
Homebrew 4.0.19

// swagger code gen brew package version
swagger-codegen: stable 3.0.44 (bottled)

// swagger nest js package
`@nestjs/swagger": "^6.3.0`

🧰 Command line used for generation

swagger-codegen generate -i http://localhost:3000/swagger-json -l typescript-angular -o myGeneratedFilesFolder/

🔁 Steps to reproduce

• Create a typescript class with nullable fields
• Try to generated it with swagger-codegen

Start by reproducing the issue with the NestJS-generated Swagger JSON and the swagger-codegen generate command using the typescript-angular generator. Trace how the nullable field is represented in the input and generated model; done means the output preserves the field's nullable type and a regression case covers the reproduction.