Nuget package dependency tree.

nuget_dependency_tree.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using NuGet;

namespace ConsoleApplication1
{
    class Program
    {
        static Dictionary<string, IPackage> cache = new Dictionary<string, IPackage>();

        static void Main()
        {
            var repo = getRepo();
            IQueryable<IPackage> packages = repo.GetPackages();
            OutputGraph(repo, packages, 0);

            Console.WriteLine("done");

            Console.ReadLine();
        }

        static IPackageRepository getRepo()
        {
            return new LocalPackageRepository(@"D:\azure-pipelines-coveragepublisher\packages\microsoft.teamfoundation.publishtestresults\16.153.0-preview");
        }

        static void OutputGraph(IPackageRepository repository, IEnumerable<IPackage> packages, int depth)
        {
            var packageSource = "https://www.nuget.org/api/v2/";
            //var packageSource = Path.Combine(Environment.GetEnvironmentVariable("LocalAppData"), "NuGet", "Cache");
            var repo = PackageRepositoryFactory.Default.CreateRepository(packageSource);

            foreach (IPackage package in packages)
            {
                Console.WriteLine("{0}{1} v{2}", new string(' ', depth), package.Id, package.Version);

                Dictionary<string, IPackage> dependentPackages = new Dictionary<string, IPackage>();
                foreach (var dependency in package.DependencySets.SelectMany(i => i.Dependencies))
                {
                    if(dependency.Id.StartsWith("System"))
                    {
                        continue;
                    }

                    var key = dependency.Id + dependency.VersionSpec.MinVersion;

                    if (cache.ContainsKey(key))
                    {
                        if (!dependentPackages.ContainsKey(key))
                        {
                            dependentPackages.Add(key, cache[key]);
                        }
                        continue;
                    }

                    var entry = repo.FindPackage(dependency.Id, dependency.VersionSpec, true, true);

                    if (!dependentPackages.ContainsKey(key))
                    {
                        dependentPackages.Add(key, entry);
                    }

                    cache.Add(key, entry);
                }

                OutputGraph(repository, dependentPackages.Values.ToList(), depth + 3);
            }
        }
    }
}