Find Github pull requests that are then tweeted. Implemented with Rx.Net in C#.

VanityPullRequests.cs

/*
 * Github commits that are then tweeted.
 * by @gousiosg, @headinthebox
 */
void Main()
{
    var q = from ghinfo in PullRequestersInfo()
        from u in ghinfo
        from t in Tweets(u).TakeUntil(Observable.Timer(TimeSpan.FromMinutes(5)))
        select new {User = u, Tweet = t};
    q.DumpLive();
}

public static IObservable<IEnumerable<String>> PullRequesters() 
{
    return PullRequesters(TimeSpan.FromSeconds(6));
}

public static IObservable<IEnumerable<String>> PullRequesters(TimeSpan interval) 
{
    return Observable.Timer(TimeSpan.Zero, interval).SelectMany( _ => 
        ReadGithubAsync("foo", "bar")
    ).DistinctUntilChanged();
}

public static IObservable<IGroupedObservable<String, String>> PullRequestersInfo() 
{
    var u = from users in PullRequesters()
        from user in users select user;

    var groups = from user in u
        group user by user;

    return groups;
}

public static async Task<IEnumerable<string>> ReadGithubAsync(string user, string password) { 

    var header = new AuthenticationHeaderValue(
        "Basic",
        Convert.ToBase64String(System.Text.UTF8Encoding.UTF8.GetBytes(string.Format("{0}:{1}", user, password)))
    );
    var client = new HttpClient{ 
            BaseAddress = new Uri("https://api.github.com/"),
            DefaultRequestHeaders = {Authorization = header}
        };
    client.DefaultRequestHeaders.Add("user-agent", "rx-example");
    var response = await client.GetAsync("/events");
    var json = await response.Content.ReadAsStringAsync();

    return (from e in JArray.Parse(json).Children()
            where (string)e["type"] == "PullRequestEvent" && (string)e["payload"]["action"] == "opened"
            select (string)e["actor"]["login"]);
}

public static IObservable<string> Tweets(string user) 
{
    return Observable.Timer(TimeSpan.Zero, TimeSpan.FromSeconds(10))
        .SelectMany(_ => ReadTwitterAsync(user))
        .Scan(new string[]{}, (a,v) => 
        {
            var diff = v.Except(a).ToArray();
            if(diff.Length == 0) return a;
            return diff;
        })
        .DistinctUntilChanged()
        .SelectMany(ts => ts);
}

public static async Task<IEnumerable<string>> ReadTwitterAsync(string user) 
{
    var client = new HttpClient{ BaseAddress = new Uri("http://search.twitter.com/search.json")};
    var response = await client.GetAsync(String.Format("?q={0}", user));
    var json = await response.Content.ReadAsStringAsync();
    
    var tweets = from e in JValue.Parse(json)["results"]
                 where (string)e["from_user"] == user &&
                    Regex.Match((string)e["text"], "github.com/.*/pulls/").Success
                 select new{ Text = (string)e["text"], From = (string)e["from_user"] };

    return tweets.Select(x => x.Text);
}

Vreadme.md

Meant to be run in LinqPad. To setup, install the newest version of .Net and using NuGet install the following packages:

• Newtonsoft.Json
• Rx-Main

Linqpad requires the following namespace imports to run this example

• Newtonsoft.Json
• Newtonsoft.Json.Bson
• Newtonsoft.Json.Converters
• Newtonsoft.Json.Linq
• Newtonsoft.Json.Schema
• Newtonsoft.Json.Serialization
• System.Net
• System.Net.Http
• System.Reactive
• System.Reactive.Linq
• System.Runtime.Serialization
• System.Runtime.Serialization.Json
• System.Threading.Tasks
• System.Net.Http.Headers