Supporting multiple versions of NuGet package in one library / NuGet package

Question

What I want

I want my library to work with a range of versions of a NuGet package with breaking changes in API between the changes. I haven\'t investigated it furt

Answer 1

If you insist on extern aliases - you can add multiple version references directly, as dll file, not as nuget package.

Suppose I want to take a dependency on Newtonsoft.Json package version 10.0.3+. However if user has version 11 installed - I want to use generic JsonConverter class available only in this version (11). Then my csproj might look like this:

  
    netstandard2.0
    1.0.4
  
  
    
    
    
  
  
    
    
      
      Newtonsoft.Json.v11.dll
      js11
      true
        
  

Then I have proxy interface:

public interface ISerializer {
    string Serialize(T obj);
}

And two implementations, v10 (uses global, non-aliased namespace):

using System;
using global::Newtonsoft.Json;

namespace NugetRefMain {
    internal class Js10Serializer : ISerializer
    {
        public string Serialize(T obj)
        {
            Console.WriteLine(typeof(JsonConvert));
            return JsonConvert.SerializeObject(obj);
        }
    }
}

And v11

extern alias js11;
using System;
using js11::Newtonsoft.Json;

namespace NugetRefMain {
    internal class Js11Serializer : ISerializer {
        public string Serialize(T obj) {
            // using JsonConverter, only available in v11
            Console.WriteLine(typeof(JsonConverter));
            return JsonConvert.SerializeObject(obj);
        }
    }
}

And finally factory which creates serializer depending on current available json.net version:

public static class Serializers {
    public static ISerializer Create() {
        var version = typeof(JsonConvert).Assembly.GetName().Version;
        if (version.Major == 10)
            return new Js10Serializer();
        return new Js11Serializer();
    }
}

Now if I pack this as nuget - it will have single dependency on Newtonsoft.Json version 10.0.3 and that's all. However, if user installs Newtonsoft.Json of version 11 - it will use capabilities available in this version.

Drawbacks:

• Visual Studio \ Resharper intellisense doesn't like this approach sometimes and shows intellisense errors when in reality everything compiles just fine.

• You might have "version conflict" warnings on compilation.