Build request URI with query parameters from base Uri and suffix (.NET) - encodes URI components

ComposeRequestUri.cs

public static Uri ComposeRequestUri(string baseUri, string pathSuffix=null, IDictionary<string, object> queryParameters=null)
{
    if (string.IsNullOrEmpty(baseUri))
    {
        throw new ArgumentException($"{nameof(baseUri)} is required", nameof(baseUri));
    }

    var uri = new Uri(baseUri);

    if (!string.IsNullOrEmpty(pathSuffix))
    {
        if (pathSuffix.StartsWith("/"))
        {
            throw new ArgumentException($"{nameof(pathSuffix)} must be relative");
        }

        uri = new Uri(uri, pathSuffix);
    }

    var uriBuilder = new UriBuilder(uri);

    if (uriBuilder.Uri.IsDefaultPort)
    {
        uriBuilder.Port = -1; // Omit port in Uri if it's the default port for the scheme
    }

    if (queryParameters != null)
    {
        var query = System.Web.HttpUtility.ParseQueryString(uriBuilder.Query);
        foreach (var pair in queryParameters)
        {
            query[pair.Key] = pair.Value.ToString();
        }

        uriBuilder.Query = query.ToString();
    }

    return uriBuilder.Uri;
}