C# command-line parser

ToggleParser.cs

/// <summary>
/// Simple command line toggles parser: 
///  - toggles are identified with (any number of) '-' prefixes
///  - toggle can be with or without associated value 
///  - toggles are case-insensitive
/// 
/// <example>--toggle_without_value -toggle value</example>
/// </summary>
public class ToggleParser
{
    private readonly Dictionary<string, string> toggles;

    public ToggleParser(string[] args)
    {
        toggles =
            args.Zip(args.Skip(1).Concat(new[] { string.Empty }), (first, second) => new { first, second })
                .Where(pair => IsToggle(pair.first))
                .ToDictionary(pair => RemovePrefix(pair.first).ToLowerInvariant(), g => IsToggle(g.second) ? string.Empty : g.second);
    }

    private static string RemovePrefix(string toggle)
    {
        return new string(toggle.SkipWhile(c => c == '-').ToArray());
    }

    private static bool IsToggle(string arg)
    {
        return arg.StartsWith("-", StringComparison.InvariantCulture);
    }

    public bool HasToggle(string toggle)
    {
        return toggles.ContainsKey(toggle.ToLowerInvariant());
    }

    public string GetToggleValueOrDefault(string toggle, string defaultValue)
    {
        string value;
        return toggles.TryGetValue(toggle.ToLowerInvariant(), out value) ? value : defaultValue;
    }
}

ToggleParserTest.cs

public class ToggleParserTest
{
    public static IEnumerable<object[]> Arguments => new[]
    {
        new object[] { new[] {"-silent", "-session", "foobar"}, true, true, "foobar" },
        new object[] { new[] {"-session", "foobar", "-silent"}, true, true, "foobar" },
        new object[] { new[] {"-silent"}, true, false, string.Empty },
        new object[] { new string[] {}, false, false, string.Empty },
        new object[] { new[] {"--SeSSION", "foobar"}, false, true, "foobar" },
    };

    [Theory, MemberData(nameof(Arguments))]
    internal void ToggleParser_ParsesToggles(string[] args, bool hasSilent, bool hasSession, string expectedSession)
    {
        // Act
        var parser = new ToggleParser(args);

        // Assert
        parser.HasToggle("silent").Should().Be(hasSilent);
        parser.HasToggle("session").Should().Be(hasSession);
        parser.GetToggleValueOrDefault("session", string.Empty).Should().Be(expectedSession);
    }
  }