Swagger shows "No operations defined in spec!"

[Theo Tzaferis]

Describe the issue
Hello,

we are writing an Azure function with HTTPTrigger that already exists. We now want to add OpenAPI specifications for it.

What I did is the following

1. Added the package <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.OpenApi" Version="1.5.1" /> (below there is full .csproj reference)

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <AzureFunctionsVersion>v4</AzureFunctionsVersion>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.Azure.Functions.Extensions" Version="1.1.0"/>
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.DurableTask" Version="2.9.6"/>
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.OpenApi" Version="1.5.1"/>
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.ServiceBus" Version="4.3.0"/>
    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="6.0.1"/>
    <PackageReference Include="Microsoft.Extensions.Hosting" Version="6.0.1"/>
    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="6.0.4"/>
    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="4.2.0"/>
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="6.0.19">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
  </ItemGroup>
  <ItemGroup>
    <ProjectReference Include="..\PM.OS.Audience.DataQueryService.Service.Application\PM.OS.Audience.DataQueryService.Service.Application.csproj"/>
    <ProjectReference Include="..\PM.OS.Audience.DataQueryService.Service.Infra.AudienceApi\PM.OS.Audience.DataQueryService.Service.Infra.AudienceApi.csproj"/>
    <ProjectReference Include="..\PM.OS.Audience.DataQueryService.Service.Infra.DataSourceApi\PM.OS.Audience.DataQueryService.Service.Infra.DataSourceApi.csproj"/>
    <ProjectReference Include="..\PM.OS.Audience.DataQueryService.Service.Infra.EntityFrameworkCore.Sql\PM.OS.Audience.DataQueryService.Service.Infra.EntityFrameworkCore.Sql.csproj"/>
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
  <Target Name="CopyCustomContent" AfterTargets="AfterBuild">
    <ItemGroup>
      <_CustomFiles Include="..\..\automation\commit-msg"/>
      <_CustomFiles Include="..\..\automation\pre-push"/>
    </ItemGroup>
    <Copy SourceFiles="@(_CustomFiles)" DestinationFolder="./../../.git/hooks"/>
  </Target>
</Project>

2. In Startup.cs configure the OpenAPI options

builder.Services.AddSingleton<IOpenApiConfigurationOptions>(
    _ =>
    {
        OpenApiConfigurationOptions options = new OpenApiConfigurationOptions
        {
            Info = new OpenApiInfo
            {
                Version = "v1",
                Title = "PM.OS.Audience.DataQueryService.Service",
            },
            Servers = DefaultOpenApiConfigurationOptions.GetHostNames(),
            OpenApiVersion = OpenApiVersionType.V3,
            IncludeRequestingHostName = true,
            ForceHttps = false,
            ForceHttp = false,
        };
        return options;
    });

4. In the HTTPFunction add the OppenAPI tags

    [FunctionName(nameof(HttpTriggerFunction))]
    [OpenApiOperation(operationId: nameof(HttpTriggerFunction))]
    [OpenApiRequestBody("application/json", typeof(CancelProcessModel), Description = "Cancel Id")]
    [OpenApiResponseWithBody(HttpStatusCode.OK, "application/json", typeof(object))]
    [OpenApiResponseWithBody(HttpStatusCode.InternalServerError, bodyType: typeof(Exception),
        contentType: "application/json")]

When I start my function app, I get the Swagger UI but it always says that there are no specs. This is the result json of the swagger

{
  "openapi": "3.0.1",
  "info": {
    "title": "PM.OS.Audience.DataQueryService.Service",
    "version": "v1"
  },
  "servers": [
    {
      "url": "http://localhost:7071/api"
    }
  ],
  "paths": { },
  "components": { }
}

It's the exact same code we have in another project where it works. I also visited 2 sites to explain how to implement it and did it the same way. Why could it be that there are still no operations defined?

To Reproduce
I don't know if it's easy to reproduce, because as I wrote above in another project it is working as expected, so it doesn't seem to be a general bug, but I can't find the reason for it.

Expected behavior
Swagger contains the operations

Screenshots
Not applicable

Environment (please complete the following information, if applicable):

• OS: Windows
• Browser not important
• Version not important

Additional context
I will gladly add additional context if needed.

[Theo Tzaferis]

Hi everyone,

I gladly found the issue. One of our developers added a reference to a test project (whysoever). I figured this out by creating a new solution and copying one file after the other to test when it stops working. After I wanted to copy the .csproj file I saw that there were two weird entries

1. Content remove for a user-defined directory
2. Refernce to a test project

After removing those two, Swagger was generated without any issue.

Since this is not a bug, but just a misconfiguration on our side, I will close the issue.