v2: Unexpected error when loading sample OpenAPI document

[captainsafia]

I am running into unexpected errors when loading an OpenAPI document from tests via the OpenApiDocument.Load APIs in 2.0.0-preview4.

Repro code:

using Microsoft.OpenApi;
using Microsoft.OpenApi.Models;
using System.IO;
using System.Text;

var contents = """
{
  "openapi": "3.1.1",
  "info": {
    "title": "GetDocumentSample | v1",
    "version": "1.0.0"
  },
  "paths": {
    "/hello/{name}": {
      "get": {
        "tags": [
          {
            "name": "GetDocumentSample"
          }
        ],
        "parameters": [
          {
            "name": "name",
            "in": "path",
            "required": true,
            "schema": {
              "type": "string"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "OK",
            "content": {
              "text/plain": {
                "schema": {
                  "type": "string"
                }
              }
            }
          }
        }
      }
    }
  },
  "tags": [
    {
      "name": "GetDocumentSample"
    }
  ]
}
""";

var (Document, Diagnostic) = OpenApiDocument.Load(new MemoryStream(Encoding.UTF8.GetBytes(contents)), "json");
foreach (var error in Diagnostic.Errors)
{
	System.Console.WriteLine(error);
}

Produces the following error:

Expected a value.

There is no node associated with the error so it's not possible to determine what aspect of the document are incorrect. This document was serialized using the same version of the Microsoft.OpenApi package.

[MaggieKimani1]

The issue stems from the tags value defined at the operation level.
Our parser expects to find an array of string but instead runs into a tag object which is invalid according to the spec:

The root-level tags object however can be used to define multiple tag objects with additional metadata e.g: name, description etc.

This should work:

var contents = """
{
  "openapi": "3.1.1",
  "info": {
    "title": "GetDocumentSample | v1",
    "version": "1.0.0"
  },
  "paths": {
    "/hello/{name}": {
      "get": {
        "tags": [
          "GetDocumentSample"
        ],
        "parameters": [
          {
            "name": "name",
            "in": "path",
            "required": true,
            "schema": {
              "type": "string"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "OK",
            "content": {
              "text/plain": {
                "schema": {
                  "type": "string"
                }
              }
            }
          }
        }
      }
    }
  },
  "tags": [
    {
      "name": "GetDocumentSample"
    }
  ]
}
""";

[captainsafia]

@MaggieKimani1 The OpenAPI document that I used in the example was serialized by the package itself so it seems like OpenAPI.NET is serializing operation-level tags in a way that it can be parsed by the package?

[MaggieKimani1]

Could you please share the initial document you're working with before serialization for repro purposes?

[captainsafia]

@MaggieKimani1 I updated the repro code to include the full round-tripping.

using Microsoft.OpenApi;
using Microsoft.OpenApi.Models;
using Microsoft.OpenApi.Writers;
using System.IO;
using System.Text;
using System.Collections.Generic;

var openApiDocument = new OpenApiDocument
{
    Info = new OpenApiInfo
    {
        Title = "GetDocumentSample | v1",
        Version = "1.0.0"
    },
    Paths = new OpenApiPaths
    {
        ["/hello/{name}"] = new OpenApiPathItem
        {
            Operations = new Dictionary<OperationType, OpenApiOperation>
            {
                [OperationType.Get] = new OpenApiOperation
                {
                    Tags = new List<OpenApiTag>
                            {
                                new OpenApiTag { Name = "GetDocumentSample" }
                            },
                    Parameters = new List<OpenApiParameter>
                            {
                                new OpenApiParameter
                                {
                                    Name = "name",
                                    In = ParameterLocation.Path,
                                    Required = true,
                                    Schema = new OpenApiSchema
                                    {
                                        Type = JsonSchemaType.String,
                                    }
                                }
                            },
                    Responses = new OpenApiResponses
                    {
                        ["200"] = new OpenApiResponse
                        {
                            Description = "OK",
                            Content = new Dictionary<string, OpenApiMediaType>
                            {
                                ["text/plain"] = new OpenApiMediaType
                                {
                                    Schema = new OpenApiSchema
                                    {
                                        Type = JsonSchemaType.String
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    },
    Tags = new List<OpenApiTag>
            {
                new OpenApiTag { Name = "GetDocumentSample" }
            }
};

using var stream = new StringWriter();
var writer = new OpenApiJsonWriter(stream);
openApiDocument.SerializeAsV31(writer);
writer.Flush();

var (Document, Diagnostic) = OpenApiDocument.Load(new MemoryStream(Encoding.UTF8.GetBytes(stream.ToString())), "json");
foreach (var error in Diagnostic.Errors)
{
    System.Console.WriteLine(error);
}

[captainsafia]

@MaggieKimani1 This appears to be resolved in 2.0.0-preview5 with all the OpenApiTagReference related changes.

[baywet]

Thanks for confirming @captainsafia ! closing