Swashbuckle.aspnetcore: Wrong JsonPatchDocument type reference in V6

[knoxi]

After creating the swagger schema, the patch type definition looks different and the generated client fails to compile.
Is there a new behavior for the patch methods? Or are there new generator settings where we can handle the patch type?

V5.6.3

      "patch": {
        ...
        "requestBody": {
          "content": {
            "application/json": {
              "schema": {
                "type": "array",
                "items": {
                  "$ref": "#/components/schemas/Operation"
                },
                "nullable": true
              }
            }
          }
        },
        ...

V6:

      "patch": {
        ...
        "requestBody": {
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/ValueDtoJsonPatchDocument"
              }
            }
          }
        },
        ...

[domaindrivendev]

Difficult to troubleshoot this without more info. Could you please create a minimal app (i.e. start from empty project) that repro's the issue so I can pull it down and troubleshoot? Thanks

[knoxi]

I have attached a simplified sample of our implementation which creates and saves the swagger file in the project folder ./Swagger/service_v1.json. There you can see that there is defined a custom type for patch but this one doesn't exists somewhere.

      "patch": {
        "tags": [
          "WeatherForecast"
        ],
        "summary": "PatchWeatherForecast",
        "parameters": [
          {
            "name": "id",
            "in": "path",
            "required": true,
            "schema": {
              "type": "string",
              "format": "date-time"
            }
          }
        ],
        "requestBody": {
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/WeatherForecastJsonPatchDocument"
              }
            }
          }
        },

Sample.zip

[poveilleux]

I have encountered the same issue today upgrading from 5.6.3 to 6.1.1. I will have to wait until this is fixed before moving to the latest version.

[poveilleux]

I was able to fix the schema by doing the following MapType to basically mimic what version 5.6.3 was doing before.

options.MapType(typeof(JsonPatchDocument<>), () =>
{
    return new OpenApiSchema
    {
        Type = "array",
        Items = new OpenApiSchema
        {
            Type = "object",
            Properties =
            {
                ["value"] = new OpenApiSchema { Nullable = true },
                ["path"] = new OpenApiSchema { Type = "string", Nullable = true },
                ["op"] = new OpenApiSchema { Type = "string", Nullable = true },
                ["from"] = new OpenApiSchema { Type = "string", Nullable = true },
            },
            AdditionalPropertiesAllowed = false
        }
    };
});

[domaindrivendev]

Investigate further and confirmed this is a bug. The code was (incorrectly) assuming that ParameterInfo.ParameterType and the corresponding ModelMetadata.ModelType generated by the _ApiExplorer_ would always have the same value and could be used interchangeably. However, in some special cases incl. IJsonPatchDocument, _ApiExplorer_ will alter ModelMetadata.ModelType to reflect serialization behavior. So, the fix was to favor ModelMetadata.ModelType as per 95cb4d370e08e54eb04cf14e7e6388ca974a686e

[domaindrivendev]

Released with 6.1.2