Transformers do properly not handle fields which are both required and nullable

[yallxe]

Description

Transformers does not check whether a field is a null. As an example:
Suppose we have a schema

export type Pet = {
  id?: bigint;
  name: string;
  createdAt: Date | null;
  photoUrls: Array<string>;
  /**
   * pet status in the store
   */
  status?: 'available' | 'pending' | 'sold';
};

Here is the transformer for it

const petSchemaResponseTransformer = (data: any) => {
  if (data.id) {
    data.id = BigInt(data.id.toString());
  }

  // May result in new Date(null), because createdAt is Date | null (but still required)
  data.createdAt = new Date(data.createdAt);
  return data;
};

Reproducible example or configuration

https://stackblitz.com/edit/hey-api-client-fetch-example-2simwjzc?file=src%2Fclient%2Ftransformers.gen.ts

OpenAPI specification (optional)

Inside the stackblitz link, I changed the swagger example.

System information (optional)

No response

[bolt-new-by-stackblitz]

Start a new pull request in StackBlitz Codeflow.

• hey-api-client-fetch-example-2simwjzc (Open reproduction)

[mrlubos]

Thanks for reporting!

[mrlubos]

@yallxe this has been fixed in a previous release, please upgrade to the latest 🙌