Rust-reqwest client fails because of null values in tags arrays from petstore.swagger.io

[sverch]

Steps to Reproduce

1. Generate the rust-reqwest based client

docker run --rm -v ${PWD}:/local/out/rust/ openapitools/openapi-generator-cli generate     -i http://petstore.swagger.io/v2/swagger.json     -g rust     -o /local/out/rust/generated --additional-properties packageName=petstore_client --library=reqwest

2. Use it to call find_pets_by_status against petstore.swagger.io

use petstore_client;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let configuration = petstore_client::apis::configuration::Configuration::new();
    let apiclient = petstore_client::apis::client::APIClient::new(configuration);
    let status = vec![std::string::String::from("pending")];
    let result = apiclient.pet_api().find_pets_by_status(status);
    println!("result = {:?}", result);
    Ok(())
}

3. See error with null tags

result = Err(Reqwest(Error(Json(Error("invalid type: null, expected struct Tag", line: 1, column: 2807)))))

Background

I generated the rust-reqwest based client and tried to do a find_pets_by_status operation, but I got this error:

result = Err(Reqwest(Error(Json(Error("invalid type: null, expected struct Tag", line: 1, column: 2807)))))

Sure enough, when I hit the API directly I see that there are null values in the tags arrays for some pets:

$ curl -X GET "https://petstore.swagger.io/v2/pet/findByStatus?status=pending" -H  "accept: application/json" | jq ".[].tags"
...
[
  {
    "id": 0,
    "name": "string"
  }
]
[
  null
]
[
  null
]
[
  null
]
[
  {
    "id": 0,
    "name": "Asdasd"
  }
]
...

The spec that I generated this client from doesn't say anything about nulls being allowed:

$ curl --silent --output - http://petstore.swagger.io/v2/swagger.json | jq ".definitions.Pet.properties.tags"
{
  "type": "array",
  "xml": {
    "name": "tag",
    "wrapped": true
  },
  "items": {
    "$ref": "#/definitions/Tag"
  }
}

The spec doesn't mention null at all:

$ curl --silent --output - http://petstore.swagger.io/v2/swagger.json | jq "." | grep null
(nothing)

I'm not sure if nulls should be allowed in arrays and the client is wrong, or if they shouldn't and the server is wrong. I see this issue which makes me think null values being allowed wasn't intended to be the default.

To get it working, I had to change this line in the Pet model:

    pub tags: Option<Vec<crate::models::Tag>>,

To this:

    pub tags: Option<Vec<Option<crate::models::Tag>>>,

Thanks for your work on this project! Let me know if there's a better place I should file this.

[webron]

This repository is for the spec alone and not any of the tools. Please file the ticket with the respective product.

[sverch]

Ah, sorry @webron. I got this confused with the generator. I'll go file this there: https://github.com/OpenAPITools/openapi-generator/.