URI template parser kata

UriTemplate.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace UriTemplateTestKata
{
    public class UriTemplate
    {
        public string Template { get; }

        public UriTemplate(string template)
        {
            if (string.IsNullOrEmpty(template))
                throw new ArgumentNullException(nameof(template));

            Template = template;
        }

        public IReadOnlyDictionary<string, string> GetTokensFromUri(string uri)
        {
            if (string.IsNullOrEmpty(uri))
                throw new ArgumentNullException(nameof(uri));

            var templateTokens = Template.TrimEnd('/').Split('/');
            var uriTokens = uri.TrimEnd('/').Split('/');

            if (templateTokens.Length != uriTokens.Length)
                throw new ArgumentException("URI does not match template");

            return templateTokens
                .Select((template, index) => (token: template, value: uriTokens[index]))
                .Where(pair => pair.token.StartsWith('{') && pair.token.EndsWith('}'))
                .ToDictionary(pair => pair.token.TrimStart('{').TrimEnd('}'), pair => pair.value);
        }
    }
}

UriTemplateShould.cs

using System;
using System.Collections.Generic;
using FluentAssertions;
using Xunit;

namespace UriTemplateTestKata
{
    public class UriTemplateShould
    {
        [Fact]
        public void ThrowIfUriDoesNotMatchTemplate()
        {
            var template = new UriTemplate("/api/{stuff}/{more}");

            template.Invoking(x => x.GetTokensFromUri("/api/1")).ShouldThrow<ArgumentException>();
        }

        [Fact]
        public void GetTokensFromUri()
        {
            var template = new UriTemplate("/api/v1/users/{userId}/factors/{factorId}");

            var result = template.GetTokensFromUri("/api/v1/users/my-userId/factors/my-factorId") as IDictionary<string, string>;

            result.Count.Should().Be(2);
            result.Should().Contain("userId", "my-userId");
            result.Should().Contain("factorId", "my-factorId");
        }
    }
}

UriTemplateTestKata.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netcoreapp2.0</TargetFramework>

    <IsPackable>false</IsPackable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="FluentAssertions" Version="4.19.4" />
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.3.0-preview-20170628-02" />
    <PackageReference Include="xunit" Version="2.2.0" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.2.0" />
  </ItemGroup>

</Project>