feat: CLone repo and perform auto-merge operation

Author: twpol

Git/Project.cs

@@ -0,0 +1,96 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Text;
+
+namespace Open_Rails_Code_Bot.Git
+{
+    public class Project
+    {
+        string GitPath;
+        bool Verbose;
+
+        public Project(string gitPath, bool verbose)
+        {
+            GitPath = gitPath;
+            Verbose = verbose;
+        }
+
+        public void Init(string repository)
+        {
+            if (!Directory.Exists(GitPath))
+            {
+                Directory.CreateDirectory(GitPath);
+                RunCommand($"clone --mirror {repository} .");
+            }
+        }
+
+        public void Fetch()
+        {
+            RunCommand("fetch --update-head-ok");
+        }
+
+        public string ParseRef(string reference)
+        {
+            foreach (var line in GetCommandOutput($"rev-parse {reference}"))
+            {
+                return line;
+            }
+            throw new ApplicationException("Unable to find ref");
+        }
+
+        public void CheckoutDetached(string reference)
+        {
+            RunCommand($"checkout --quiet --detach {reference}");
+        }
+
+        public void ResetHard()
+        {
+            RunCommand("reset --hard");
+        }
+
+        public void Merge(string reference)
+        {
+            RunCommand($"merge --no-edit --no-ff {reference}");
+        }
+
+        void RunCommand(string command)
+        {
+            foreach (var line in GetCommandOutput(command))
+            {
+            }
+        }
+
+        IEnumerable<string> GetCommandOutput(string command)
+        {
+            var args = $"--no-pager {command}";
+            if (Verbose)
+            {
+                Console.WriteLine("```shell");
+                Console.WriteLine($"{GitPath}> git {args}");
+            }
+            var git = Process.Start(new ProcessStartInfo()
+            {
+                WorkingDirectory = GitPath,
+                FileName = "git",
+                Arguments = args,
+                StandardOutputEncoding = Encoding.UTF8,
+                RedirectStandardOutput = true,
+            });
+            while (!git.StandardOutput.EndOfStream)
+            {
+                yield return git.StandardOutput.ReadLine();
+            }
+            git.WaitForExit();
+            if (git.ExitCode != 0)
+            {
+                throw new ApplicationException($"git {command} failed: {git.ExitCode}");
+            }
+            if (Verbose)
+            {
+                Console.WriteLine("```");
+            }
+        }
+    }
+}

Program.cs

@@ -43,8 +43,12 @@ static async Task AsyncMain(IConfigurationRoot config)
             var gitHubConfig = config.GetSection("github");
             var query = new Query(gitHubConfig["token"]);
 
+            Console.WriteLine($"GitHub organisation: {gitHubConfig["organization"]}");
+            Console.WriteLine($"GitHub team:         {gitHubConfig["team"]}");
+            Console.WriteLine($"GitHub repository:   {gitHubConfig["repository"]}");
+
             var members = await query.GetTeamMembers(gitHubConfig["organization"], gitHubConfig["team"]);
-            Console.WriteLine($"Org '{gitHubConfig["organization"]}' team '{gitHubConfig["team"]}' members ({members.Count})");
+            Console.WriteLine($"Team members ({members.Count}):");
             foreach (var member in members)
             {
                 Console.WriteLine($"  {member.Login}");
@@ -53,7 +57,7 @@ static async Task AsyncMain(IConfigurationRoot config)
 
             var pullRequests = await query.GetOpenPullRequests(gitHubConfig["organization"], gitHubConfig["repository"]);
             var autoMergePullRequests = new List<GraphPullRequest>();
-            Console.WriteLine($"Org '{gitHubConfig["organization"]}' repo '{gitHubConfig["repository"]}' open pull requests ({pullRequests.Count})");
+            Console.WriteLine($"Open pull requests ({pullRequests.Count}):");
             foreach (var pullRequest in pullRequests)
             {
                 var autoMerge = memberLogins.Contains(pullRequest.Author.Login)
@@ -69,11 +73,53 @@ static async Task AsyncMain(IConfigurationRoot config)
                 }
             }
 
-            Console.WriteLine($"Org '{gitHubConfig["organization"]}' repo '{gitHubConfig["repository"]}' auto-merge pull requests ({autoMergePullRequests.Count})");
+            Console.WriteLine($"Pull requests suitable for auto-merging ({autoMergePullRequests.Count}):");
+            foreach (var pullRequest in autoMergePullRequests)
+            {
+                Console.WriteLine($"  #{pullRequest.Number} {pullRequest.Title}");
+            }
+
+            var git = new Git.Project(GetGitPath(), false);
+            git.Init($"https://github.com/{gitHubConfig["organization"]}/{gitHubConfig["repository"]}.git");
+            git.Fetch();
+            git.ResetHard();
+            var baseCommit = git.ParseRef("master");
+            git.CheckoutDetached(baseCommit);
+            var autoMergePullRequestsSuccess = new List<GraphPullRequest>();
+            var autoMergePullRequestsFailure = new List<GraphPullRequest>();
             foreach (var pullRequest in autoMergePullRequests)
+            {
+                var mergeCommit = git.ParseRef($"pull/{pullRequest.Number}/head");
+                try
+                {
+                    git.Merge(mergeCommit);
+                    autoMergePullRequestsSuccess.Add(pullRequest);
+                }
+                catch (ApplicationException)
+                {
+                    autoMergePullRequestsFailure.Add(pullRequest);
+                    git.ResetHard();
+                }
+            }
+            Console.WriteLine($"Final commit: {git.ParseRef("HEAD")}");
+
+            Console.WriteLine($"Pull requests successfully auto-merged ({autoMergePullRequestsSuccess.Count}):");
+            foreach (var pullRequest in autoMergePullRequestsSuccess)
+            {
+                Console.WriteLine($"  #{pullRequest.Number} {pullRequest.Title}");
+            }
+
+            Console.WriteLine($"Pull requests not auto-merged ({autoMergePullRequestsFailure.Count}):");
+            foreach (var pullRequest in autoMergePullRequestsFailure)
             {
                 Console.WriteLine($"  #{pullRequest.Number} {pullRequest.Title}");
             }
         }
+
+        static string GetGitPath()
+        {
+            var appFilePath = System.Reflection.Assembly.GetEntryAssembly().Location;
+            return Path.Combine(Path.GetDirectoryName(appFilePath), "git");
+        }
     }
 }