CSX Script to update projects to the new format

updateToVS2017.csx

using System;
using System.IO;
using System.Xml;

const string classLibraryTemplate =
@"
<Project Sdk=""Microsoft.NET.Sdk"">
  <PropertyGroup>
    <TargetFramework>net461</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
##Packages
  </ItemGroup>
</Project>
";

const string exeTemplate = @"
<Project Sdk=""Microsoft.NET.Sdk"">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net461</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
##Packages
  </ItemGroup>
</Project>
";

const string testTemplate =
@"
<Project Sdk=""Microsoft.NET.Sdk"">
  <PropertyGroup>
    <TargetFramework>net46</TargetFramework>
  </PropertyGroup>
  <ItemGroup>##Packages</ItemGroup>
  <ItemGroup>
    <PackageReference Include=""Microsoft.NET.Test.Sdk"" Version=""15.0.0"" />
    <PackageReference Include=""xunit"" Version=""2.2.0"" />
    <PackageReference Include=""xunit.runner.visualstudio"" Version=""2.2.0"" />
  </ItemGroup>
  <ItemGroup>
##Packages
  </ItemGroup>

</Project>
";


string ConvertPackages(string fullPathToProject)
{
    var packagesStr = new System.Text.StringBuilder();
    var projectDir = Path.GetDirectoryName(fullPathToProject);
    var packagesFile = Path.Combine(projectDir, "packages.config");
    if (File.Exists(packagesFile))
    {
        var doc = new XmlDocument();
        doc.Load(packagesFile);
        var packages = doc.SelectNodes("//package");
        foreach (System.Xml.XmlElement p in packages)
        {
            packagesStr.AppendLine($"<PackageReference Include=\"{p.Attributes["id"].Value}\" Version=\"{p.Attributes["version"]}\" />");
        }
    }
    return packagesStr.ToString();
}

void ConvertLibrary(string fullPathToProject) {
    var fileNameWithoutExt = Path.GetFileNameWithoutExtension(fullPathToProject);
    var newProjectFile = Path.Combine(fileNameWithoutExt, ".New.csproj");
    var packages = ConvertPackages(fullPathToProject);
    File.WriteAllText(newProjectFile, classLibraryTemplate.Replace("##Packages", packages));
}

void ConvertExe(string fullPathToProject) {
    var fileNameWithoutExt = Path.GetFileNameWithoutExtension(fullPathToProject);
    var newProjectFile = Path.Combine(fileNameWithoutExt, ".New.csproj");
    var packages = ConvertPackages(fullPathToProject);
    File.WriteAllText(newProjectFile, exeTemplate.Replace("##Packages", packages));

}

void ConvertTest(string fullPathToProject) {
    var fileNameWithoutExt = Path.GetFileNameWithoutExtension(fullPathToProject);
    var newProjectFile = Path.Combine(fileNameWithoutExt, ".New.csproj");
    var packages = ConvertPackages(fullPathToProject);
    File.WriteAllText(newProjectFile, testTemplate.Replace("##Packages", packages));

}