Open API documentation is not generated from XML comments with header parameters

[vijuhe]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

There is a controller endpoint with request parameters. One of the request parameters is taken from the request header and is therefore decorated with the [FromHeader] attribute. The parameter is described in the controller method comments in a param element just like all the other request parameters. The setting GenerateDocumentationFile is on in the API project and the XML documentation is correctly generated to the build output folder and the documentation includes the header parameter description.

However, when generating the Open API JSON document at run-time, the header parameter description is missing from the output.

Expected Behavior

All the parameter descriptions are in the Open API documentation, including header parameters.

Steps To Reproduce

Create a new API project with Open API support.
Add a controller method with a header parameter.
Document the controller method in code comments.
Turn on documentation file generation for the project.
Start the API,
Execute Open API documentation generation.

Exceptions (if any)

No response

.NET Version

10.0

Anything else?

No response

[khellang]

@vijuhe I'm assuming you're also specifying a custom name for the header in the FromHeader attribute? If that's the case, then this should likely be fixed by #64535

[vchirikov]

@khellang yep, I found the same behavior when use a custom name in FromHeader attribute ([FromHeader(Name = "accept")]). Thanks for the update

[vijuhe]

@vijuhe I'm assuming you're also specifying a custom name for the header in the FromHeader attribute? If that's the case, then this should likely be fixed by #64535

Yes, correct, the Name property is set in FromHeader.

[khellang]

Yes, correct, the Name property is set in FromHeader.

Alright, then #64535 should definitely fix it. I even tried writing a test with FromHeader which passed 👍🏻