Microsoft.OData: A factory of JSON readers that report all properties with an initial lowercase.

LowercasePropertyJsonReaderFactory.cs

using System.IO;
using System.Web.OData.Builder;
using Microsoft.OData.Json;

/// <summary>
/// A factory of JSON readers that report all properties with an initial lowercase.
/// This can be used by an ODATA service to accept payloads with mixed/incorrect case in property names.
/// Install it as the default IJsonReaderFactory in the service startup with this, given the IContainerBuilder builder,
/// ie, in the callback of MapODataServiceRoute:
///   var defaultServices = builder.BuildContainer();
///   var defaultJsonReaderFactory = (IJsonReaderFactory)defaultServices.GetService(typeof(IJsonReaderFactory));
///   builder.AddService<IJsonReaderFactory>(ServiceLifetime.Singleton, _ => new LowercasePropertyJsonReaderFactory(defaultJsonReaderFactory));      
/// </summary>
public class LowercasePropertyJsonReaderFactory : IJsonReaderFactory
{
    private IJsonReaderFactory defaultFactory;

    public LowercasePropertyJsonReaderFactory(IJsonReaderFactory defaultFactory)
    {
        this.defaultFactory = defaultFactory;
    }

    public IJsonReader CreateJsonReader(TextReader textReader, bool isIeee754Compatible)
    {
        var defaultReader = this.defaultFactory.CreateJsonReader(textReader, isIeee754Compatible);
        return new JsonReader(defaultReader);
    }

    private class JsonReader : IJsonReader
    {
        private static readonly LowerCamelCaser LowerCamelCaser = new LowerCamelCaser();
        private IJsonReader defaultReader;

        public JsonReader(IJsonReader defaultReader)
        {
            this.defaultReader = defaultReader;
        }

        public object Value
        {
            get
            {
                var value = this.defaultReader.Value;
                if (this.NodeType == JsonNodeType.Property && value is string strValue)
                {
                    value = LowerCamelCaser.ToLowerCamelCase(strValue);
                }
                return value;
            }
        }

        public JsonNodeType NodeType => this.defaultReader.NodeType;

        public bool IsIeee754Compatible => this.defaultReader.IsIeee754Compatible;

        public bool Read() => this.defaultReader.Read();
    }
}