BUG: Object reference not set.... .net 6 functions

Describe the issue When using this library in a new Azure Functions project (.net6, runtime V4) it works locally but not on Azure.

Object reference not set to an instance of an object.

To Reproduce

1. Create new Azure functions project with .Net 6
2. Add a new project without dependencies and reference it in your functions project
3. Deploy to Azure
4. Call /api/swagger.json

Expected behavior I expect that swagger would just work like it does locally.

Screenshots

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

• OS: Azure (Windows Service plan, FUNCTIONS_EXTENSION_VERSION = ~4, FUNCTIONS_WORKER_RUNTIME = dotnet)
• Version 1.0.0 (nuget)

[chris-parker-bliss]

Hi @justinyoo - I can confirm that even after updating to v1.3.0 of the Microsoft.Azure.WebJobs.Extensions.OpenApi package I’m still seeing the following error when my function app references a net6.0 class library which has no dependencies:

Object reference not set to an instance of an object.

   at Microsoft.Azure.WebJobs.Extensions.OpenApi.OpenApiHttpTriggerContext.<>c.<GetRuntimeFilenameAsync>b__43_1(KeyValuePair`2 target)
   at System.Linq.Utilities.<>c__DisplayClass2_0`3.<CombineSelectors>b__0(TSource x)
   at System.Linq.Enumerable.SelectListIterator`2.MoveNext()
   at System.Linq.Enumerable.SelectManySingleSelectorIterator`2.MoveNext()
   at System.Linq.Enumerable.Contains[TSource](IEnumerable`1 source, TSource value, IEqualityComparer`1 comparer)
   at Microsoft.Azure.WebJobs.Extensions.OpenApi.OpenApiHttpTriggerContext.<>c__DisplayClass43_0.<GetRuntimeFilenameAsync>b__3(<>f__AnonymousType0`3 r)
   at System.Linq.Enumerable.TryGetFirst[TSource](IEnumerable`1 source, Func`2 predicate, Boolean& found)
   at Microsoft.Azure.WebJobs.Extensions.OpenApi.OpenApiHttpTriggerContext.GetRuntimeFilenameAsync(String functionAppDirectory)
   at Microsoft.Azure.WebJobs.Extensions.OpenApi.OpenApiHttpTriggerContext.SetApplicationAssemblyAsync(String functionAppDirectory, Boolean appendBin)
   at Microsoft.Azure.WebJobs.Extensions.OpenApi.Core.Extensions.OpenApiHttpTriggerContextExtensions.AuthorizeAsync(Task`1 context, IHttpRequestDataObject req)
   at Microsoft.Azure.WebJobs.Extensions.OpenApi.OpenApiTriggerFunctionProvider.RenderSwaggerUI(HttpRequest req, ExecutionContext ctx, ILogger log)

[PedroLucasSilva]

I had the same problem and I solved it based on an old issue. Where the person indicated that all projects on their system must have at least one dependency. I added a random package to a project of mine that didn’t have any and it started working.