Constants generator from Godot's input map

InputMapGenerator.cs

using Microsoft.CodeAnalysis;
using System.Collections.Immutable;
using System.Linq;
using System.Text;

namespace SourceGenerators;

[Generator(LanguageNames.CSharp)]
public class InputMapGenerator : IIncrementalGenerator
{
    public void Initialize(IncrementalGeneratorInitializationContext context)
    {
        var additionalTexts = context.AdditionalTextsProvider.Where(static (file) =>
            file.Path.EndsWith("project.godot")
        );

        var additionalTextsContent = additionalTexts.Select(static (additionalText, cancellationToken) =>
            additionalText.GetText(cancellationToken)!.ToString()
        );

        var inputActions = additionalTextsContent.SelectMany(static (additionalTextContent, _) =>
            additionalTextContent.Split('\n')
                                 .Where(static (line) => !string.IsNullOrWhiteSpace(line))
                                 .SkipWhile(static (line) => !line.StartsWith("[input]")).Skip(1)
                                 .TakeWhile(static (line) => !line.StartsWith("["))
                                 .Where(static (line) => line.IndexOf('=') > 0)
                                 .Select(static (line) => line.Split('=')[0])
        );

        var collected = inputActions.Collect();

        context.RegisterSourceOutput(collected, CreateSource);
    }

    private static void CreateSource(SourceProductionContext context, ImmutableArray<string> inputActions)
    {
        var source = new StringBuilder();
        _ = source.AppendLine("/*\n   This file was generated.\n   Do not edit.\n*/")
                  .AppendLine()
                  .AppendLine("using Godot;")
                  .AppendLine()
                  .AppendLine("namespace YOUR_NAMESPACE_HERE;")
                  .AppendLine()
                  .AppendLine("public static class InputMap")
                  .AppendLine("{");

        foreach (var inputAction in inputActions)
        {
            var name = InputActiontoConstant(inputAction);
            var value = $"\"{inputAction}\"";
            _ = source.AppendLine($"    public static readonly StringName {name} = {value};");
        }

        _ = source.AppendLine("}");

        context.AddSource("InputMap.g.cs", source.ToString());
    }

    private static string InputActiontoConstant(string inputAction)
    {
        // Specific naming conventions can be implemented here.
        // Ours is: PascalCase, with specific edge cases (like ui should be translated as UI).
        return string.Join("", inputAction.Replace('.', '_').Split('_').Where(word => word.Length > 0).Select(
            static (word) => word.ToLowerInvariant() switch
            {
                "ui" => "UI",
                _ => $"{word.Substring(0, 1).ToUpperInvariant()}{word.Substring(1)}",
            }
        ));
    }
}