Problem with optional enum query parameter?

[whophil]

I am having trouble making calls to the API when the endpoint directly uses an optional enum query parameter.

I have followed this section of the docs, but am running into issues which do not seem to be covered.

I have created a minimal openapi.json as shown below. This API has one endpoint, /data/ which takes one query parameter unit_system, which is allowed to be either "SI" or "FPS" - or it can be null.

openapi.json

{
    "openapi": "3.1.0",
    "info":
    {
        "title": "FastAPI",
        "version": "0.1.0"
    },
    "paths":
    {
        "/data/":
        {
            "get":
            {
                "summary": "Get Data",
                "operationId": "get_data",
                "parameters":
                [
                    {
                        "name": "unit_system",
                        "in": "query",
                        "required": false,
                        "schema":
                        {
                            "anyOf":
                            [
                                {
                                    "$ref": "#/components/schemas/UnitSystem"
                                },
                                {
                                    "type": "null"
                                }
                            ],
                            "title": "Unit System"
                        }
                    }
                ],
                "responses":
                {
                    "200":
                    {
                        "description": "Successful Response",
                        "content":
                        {
                            "application/json":
                            {
                                "schema":
                                {
                                    "type": "string",
                                    "title": "Response Get Data"
                                }
                            }
                        }
                    },
                    "422":
                    {
                        "description": "Validation Error",
                        "content":
                        {
                            "application/json":
                            {
                                "schema":
                                {
                                    "$ref": "#/components/schemas/HTTPValidationError"
                                }
                            }
                        }
                    }
                }
            }
        }
    },
    "components":
    {
        "schemas":
        {
            "HTTPValidationError":
            {
                "properties":
                {
                    "detail":
                    {
                        "items":
                        {
                            "$ref": "#/components/schemas/ValidationError"
                        },
                        "type": "array",
                        "title": "Detail"
                    }
                },
                "type": "object",
                "title": "HTTPValidationError"
            },
            "UnitSystem":
            {
                "type": "string",
                "enum":
                [
                    "SI",
                    "FPS"
                ],
                "title": "UnitSystem"
            },
            "ValidationError":
            {
                "properties":
                {
                    "loc":
                    {
                        "items":
                        {
                            "anyOf":
                            [
                                {
                                    "type": "string"
                                },
                                {
                                    "type": "integer"
                                }
                            ]
                        },
                        "type": "array",
                        "title": "Location"
                    },
                    "msg":
                    {
                        "type": "string",
                        "title": "Message"
                    },
                    "type":
                    {
                        "type": "string",
                        "title": "Error Type"
                    }
                },
                "type": "object",
                "required":
                [
                    "loc",
                    "msg",
                    "type"
                ],
                "title": "ValidationError"
            }
        }
    }
}

I generate the client code via:

npx @openapitools/openapi-generator-cli \
	--custom-generator MATLAB/lib/jar/MATLABClientCodegen-openapi-generator-0.0.1.jar \
	generate \
	-g MATLAB \
	-i http://localhost:8000/openapi.json \
	--package-name exampleclient

This generates the following tree:

+exampleclient
├── +api
│   └── Default.m
├── +models
│   ├── FreeFormObject.m
│   ├── HTTPValidationError.m
│   ├── UnitSystem.m
│   ├── Unit_System.m
│   ├── ValidationError.m
│   └── ValidationError_loc_inner.m
├── BaseClient.m
├── CookieJar.m
├── JSONEnum.m
├── JSONMapper.m
├── JSONMapperMap.m
└── JSONPropertyInfo.m

After this, I run into issues when querying. The output below demonstrates trying to call the endpoint in a number of different ways. All of these fail on the Matlab side before even attempting to communicate with the API.

Am I making a mistake, or is this somehow an edge case that is currently not working?

Errors when attempting to use the generated enum models

>> client = exampleclient.api.Default(serverUri="http://localhost:8000")

client = 

  Default with properties:

              serverUri: [1×1 matlab.net.URI]
            httpOptions: [1×1 matlab.net.http.HTTPOptions]
    preferredAuthMethod: [0×0 string]
            bearerToken: '<unset>'
                 apiKey: '<unset>'
        httpCredentials: '<unset>'
                cookies: [1×1 exampleclient.CookieJar]

>> client.getData(unit_system="SI")
Error using matlab.net.QueryParameter>convert
Unable to convert the value of the query parameter
"unit_system" of type exampleclient.models.Unit_System
to a string.

Error in matlab.net.QueryParameter/string (line 351)
                    values = convert(obj.Name, value, obj.Literal);

Error in matlab.net.URI/string (line 673)
                query = '?' + string(obj.Query);

Error in matlab.net.URI/char (line 696)
            str = string(obj);

Error in matlab.net.http.RequestMessage>getProxySettings (line 2133)
    proxyInfo = matlab.internal.webservices.getProxyInfo(char(uri));

Error in matlab.net.http.RequestMessage/send (line 405)
                    [proxyURI, username, password] = getProxySettings(createURIFromInput(uri));

Error in exampleclient.api.Default/getData (line 175)
            [response, ~, history] = send(request, uri, httpOptions);
 
>> client.getData(unit_system=exampleclient.models.UnitSystem.SI)
Error using exampleclient.api.Default/getData
 client.getData(unit_system=exampleclient.models.UnitSystem.SI)
                            ↑
Invalid value for 'unit_system' argument. Value must be of type exampleclient.models.Unit_System or be convertible
to exampleclient.models.Unit_System.
 
>> client.getData(unit_system=exampleclient.models.Unit_System("SI"))
Error using matlab.net.QueryParameter>convert
Unable to convert the value of the query parameter "unit_system" of type exampleclient.models.Unit_System to a
string.

Error in matlab.net.QueryParameter/string (line 351)
                    values = convert(obj.Name, value, obj.Literal);

Error in matlab.net.URI/string (line 673)
                query = '?' + string(obj.Query);

Error in matlab.net.URI/char (line 696)
            str = string(obj);

Error in matlab.net.http.RequestMessage>getProxySettings (line 2133)
    proxyInfo = matlab.internal.webservices.getProxyInfo(char(uri));

Error in matlab.net.http.RequestMessage/send (line 405)
                    [proxyURI, username, password] = getProxySettings(createURIFromInput(uri));

Error in exampleclient.api.Default/getData (line 175)
            [response, ~, history] = send(request, uri, httpOptions);

[brownemi]

Hi @whophil

Thanks for the report. I've not been able to replicate this exactly I see a different issue...

Could I ask you to share the output of the npx @openapitools/openapi-generator-cli version command please.

Also we've not qualified the package with 3.1.0 support yet and know of some issues, could you change the spec to use 3.0.0 (line #2 of the spec) and see how that goes as a quick test.