Invalid C# code generated when API path contains an underscore (_)

[zvrba]

What are you generating using Kiota, clients or plugins?

API Client/SDK

In what context or format are you using Kiota?

Windows executable

Client library/SDK language

Csharp

Describe the bug

When API path contains an underscore, the generated code does not compile. Please see the screenshot with condensed information.

Expected behavior

The generated code compiles regardless of quirks in API definitions.

How to reproduce

Create a minimal API definition that contains an _ in the path (as exemplified in the screenshot) and try to compile the generated C# client.

Open API description file

No response

Kiota Version

1.27.0+278d4c17bfbc9fff8d8a1618bd95b43b1e3f7f4d

Latest Kiota version known to work for scenario above?(Not required)

No response

Known Workarounds

Regex search-replace in visual studio: Replace all "(^\s+)_ = body", "$1var __D3EFECEF9C3C459FA90E066665D380F2 = body"

Configuration

No response

Debug output

No response

Other information

No response

[baywet]

Hi @zvrba
Thank you for using kiota and for reaching out.

This underscore is not added because of the API segment name. It's a (rather strange) way to validate nullability of an argument by null-coalesce + discard assignment.

The code is being generated here

kiota/src/Kiota.Builder/Writers/CSharp/CodeMethodWriter.cs

Line 34 in caa5e9c

writer.WriteLine($"_ = {parameterName} ?? throw new ArgumentNullException(nameof({parameterName}));");

And it's being tested here

kiota/tests/Kiota.Builder.Tests/Writers/CSharp/CodeMethodWriterTests.cs

Line 1945 in caa5e9c

Assert.Contains("_ = ra ?? throw new ArgumentNullException(nameof(ra));", result);

As well as here

kiota/tests/Kiota.Builder.Tests/Writers/CSharp/CodeMethodWriterTests.cs

Line 2023 in caa5e9c

Assert.Contains("_ = ra ?? throw new ArgumentNullException(nameof(ra));", result);

Is this something you'd like to submit a pull request for provided some guidance?

[zvrba]

I understand what the generated code does, though I'm very annoyed at _ namespace. I can just hope that it never explicitly surfaces out to the users of the generated client.

As for PR: I'll try to obtain permission from my employer. Also, the CLA site (https://cla.opensource.microsoft.com/) is down at the moment.

[baywet]

Thank you for the additional information.

I have reported the outage internally.

In addition, the naming of the request builder etc... could be cleaned up as well.
This is where the cleanup code lives.

kiota/src/Kiota.Builder/Extensions/StringExtensions.cs

Line 181 in caa5e9c

public static string CleanupSymbolName(this string? original)

And it's being used here (as well as a couple of other places like query parameters etc..)

kiota/src/Kiota.Builder/KiotaBuilder.cs

Line 700 in caa5e9c

Name = currentNamespace.Name.EndsWith(OpenApiUrlTreeNodeExtensions.ReservedItemNameEscaped, StringComparison.OrdinalIgnoreCase) ? className.CleanupSymbolName().Replace(OpenApiUrlTreeNodeExtensions.ReservedItemName, OpenApiUrlTreeNodeExtensions.ReservedItemNameEscaped, StringComparison.OrdinalIgnoreCase) : className.CleanupSymbolName(),

[zvrba]

Hi,

Just to let you know: my employer gave me a green light to contribute.