update auto-merge tool to support multiple repositories and options

src/Tools/Github/GitMergeBot/GitMergeBot.csproj

@@ -33,8 +33,8 @@
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="Octokit, Version=0.16.0.0, Culture=neutral, processorArchitecture=MSIL">
-      <HintPath>..\packages\Octokit.0.16.0\lib\net45\Octokit.dll</HintPath>
+    <Reference Include="Octokit, Version=0.17.0.0, Culture=neutral, processorArchitecture=MSIL">
+      <HintPath>..\..\..\..\..\packages\Octokit.0.17.0\lib\net45\Octokit.dll</HintPath>
       <Private>True</Private>
     </Reference>
     <Reference Include="System" />
@@ -47,6 +47,8 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Mono.Options\Options.cs" />
+    <Compile Include="Options.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>

src/Tools/Github/GitMergeBot/Options.cs

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System.Linq;
+
+namespace GitMergeBot
+{
+    internal sealed class Options
+    {
+        public string AuthToken { get; set; }
+        public string RepoName { get; set; }
+        public string SourceBranch { get; set; }
+        public string DestinationBranch { get; set; }
+        public string SourceUser { get; set; }
+        public string DestinationUser { get; set; }
+        public bool Debug { get; set; }
+        public bool ShowHelp { get; set; }
+
+        public bool AreValid => new[] { AuthToken, RepoName, SourceBranch, DestinationBranch, SourceUser, DestinationUser }.All(s => s != null);
+    }
+}

src/Tools/Github/GitMergeBot/Program.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
-using Octokit;
 using System;
+using System.Net;
+using System.Reflection;
 using System.Threading.Tasks;
+using Mono.Options;
+using Octokit;
 
-namespace ConsoleApplication2
+namespace GitMergeBot
 {
-
     class Program
     {
+        static int Main(string[] args)
+        {
+            var exeName = Assembly.GetExecutingAssembly().GetName().Name;
+            var options = new Options();
+
+            // default to using an environment variable, but allow an explicitly provided value to override
+            options.AuthToken = Environment.GetEnvironmentVariable("AUTH_CODE");
+            var parameters = new OptionSet()
+            {
+                $"Usage: {exeName} [options]",
+                "Create a pull request from the specified user and branch to another specified user and branch.",
+                "",
+                "Options:",
+                { "a|auth=", "The GitHub authentication token.", value => options.AuthToken = value },
+                { "r|repo=", "The name of the remote repository.", value => options.RepoName = value },
+                { "s|source=", "The source branch of the merge operation.", value => options.SourceBranch = value },
+                { "d|dest=", "The destination branch of the merge operation.", value => options.DestinationBranch = value },
+                { "su|sourceuser=", "The user hosting the source branch of the merge operation.", value => options.SourceUser = value },
+                { "du|destuser=", "The user hosting the destination branch of the merge operation.", value => options.DestinationUser = value },
+                { "debug", "Print debugging information about the merge but don't actually create the pull request.", value => options.Debug = value != null },
+                { "h|help", "Show this message and exit.", value => options.ShowHelp = value != null }
+            };
+
+            try
+            {
+                parameters.Parse(args);
+            }
+            catch (OptionException e)
+            {
+                Console.WriteLine($"{exeName}: {e.Message}");
+                Console.WriteLine($"Try `{exeName} --help` for more information.");
+                return 1;
+            }
+
+            if (options.ShowHelp || !options.AreValid)
+            {
+                parameters.WriteOptionDescriptions(Console.Out);
+                return options.AreValid ? 0 : 1;
+            }
+            else
+            {
+                var github = new GitHubClient(new ProductHeaderValue(options.SourceUser));
+                github.Credentials = new Credentials(options.AuthToken);
+                new Program().MakePullRequest(github, options).GetAwaiter().GetResult();
+                return 0;
+            }
+        }
+
+        public async Task MakePullRequest(GitHubClient github, Options options)
+        {
+
+            var remoteIntoBranch = await GetShaFromBranch(github, options.DestinationUser, options.RepoName, options.SourceBranch);
+            var newBranchName = await MakePrBranch(github, options, options.SourceUser, options.RepoName, remoteIntoBranch, $"merge-{options.SourceBranch}-into-{options.DestinationBranch}");
+            await SubmitPullRequest(github, options, newBranchName);
+            return;
+        }
+
         /// <returns> The SHA at the tip of `branchName` in the repository `user/repo` </returns>
-        static async Task<string> GetShaFromBranch(GitHubClient github, string user, string repo, string branchName) 
+        private async Task<string> GetShaFromBranch(GitHubClient github, string user, string repo, string branchName) 
         {
             var refs = await github.GitDatabase.Reference.Get(user, repo, $"heads/{branchName}");
             return refs.Object.Sha;
@@ -20,19 +79,26 @@ static async Task<string> GetShaFromBranch(GitHubClient github, string user, str
         /// Creates a PR branch on the bot account with the branch head at `sha`.
         /// </summary>
         /// <returns> The name of the branch that was created </returns>
-        static async Task<string> MakePrBranch(GitHubClient github, string user, string repo, string sha, string branchNamePrefix)
+        private async Task<string> MakePrBranch(GitHubClient github, Options options, string user, string repo, string sha, string branchNamePrefix)
         {
             var branchName = branchNamePrefix + DateTime.UtcNow.ToString("yyyyMMdd-HHmmss");
 
-            var resp = await github.Connection.Post<string>(
-                uri: new Uri($"https://api.github.com/repos/{user}/{repo}/git/refs"),
-                body: $"{{\"ref\": \"refs/heads/{branchName}\", \"sha\": \"{sha}\"", 
-                accepts: "*/*", 
-                contentType: "application/json");
-            var statusCode = resp.HttpResponse.StatusCode;
-            if (statusCode != System.Net.HttpStatusCode.Created)
+            if (options.Debug)
+            {
+                WriteDebugLine($"Create remote branch '{user}/{repo}/{branchName}' at {sha}");
+            }
+            else
             {
-                throw new Exception($"Failed creating a new branch {branchName} on {user}/{repo} with code {statusCode}");
+                var resp = await github.Connection.Post<string>(
+                    uri: new Uri($"https://api.github.com/repos/{user}/{repo}/git/refs"),
+                    body: $"{{\"ref\": \"refs/heads/{branchName}\", \"sha\": \"{sha}\"",
+                    accepts: "*/*",
+                    contentType: "application/json");
+                var statusCode = resp.HttpResponse.StatusCode;
+                if (statusCode != HttpStatusCode.Created)
+                {
+                    throw new Exception($"Failed creating a new branch {branchName} on {user}/{repo} with code {statusCode}");
+                }
             }
 
             return branchName;
@@ -41,83 +107,53 @@ static async Task<string> MakePrBranch(GitHubClient github, string user, string
         /// <summary>
         /// Creates a pull request 
         /// </summary>
-        static async Task SubmitPullRequest(GitHubClient github, string remoteUser, string myUser, string repoName, 
-                                            string newBranchName, string fromBranch, string intoBranch)
+        private async Task SubmitPullRequest(GitHubClient github, Options options, string newBranchName)
         {
-            await github.PullRequest.Create(remoteUser, repoName,
-                new NewPullRequest($"Merge {fromBranch} into {intoBranch}", head: $"{myUser}:{newBranchName}", baseRef: intoBranch) {
-                    Body = $@"
-This is an automatically generated pull request from {fromBranch} into {intoBranch}.
+            var remoteName = $"{options.SourceUser}-{options.RepoName}";
+            var prTitle = $"Merge {options.SourceBranch} into {options.DestinationBranch}";
+            var prMessage = $@"
+This is an automatically generated pull request from {options.SourceBranch} into {options.DestinationBranch}.
 
 @dotnet/roslyn-infrastructure:
 
-```bash
-git remote add roslyn-bot ""https://github.com/roslyn-bot/roslyn.git""
-git fetch roslyn-bot
+``` bash
+git remote add {remoteName} ""https://github.com/{options.SourceUser}/{options.RepoName}.git""
+git fetch {remoteName}
 git checkout {newBranchName}
-git reset --hard upstream/{intoBranch}
-git merge upstream/{fromBranch}
+git reset --hard upstream/{options.DestinationBranch}
+git merge upstream/{options.SourceBranch}
 # Fix merge conflicts
 git commit
-git push roslyn-bot {newBranchName} --force
+git push {remoteName} {newBranchName} --force
 ```
 
 Once the merge can be made and all the tests pass, you are free to merge the pull request.
+".Trim();
 
-".Trim()
-                });
-        }
-
-        static async Task MakePullRequest(GitHubClient github, string remoteUser, string myUser, string repoName, string fromBranch, string intoBranch)
-        {
-
-            var remoteIntoBranch = await GetShaFromBranch(github, remoteUser, repoName, fromBranch);
-            var newBranchName = await MakePrBranch(github, myUser, repoName, remoteIntoBranch, $"merge-{fromBranch}-into-{intoBranch}");
-            await SubmitPullRequest(github, remoteUser, myUser, repoName, newBranchName, fromBranch, intoBranch);
-            return;
-        }
-
-        static async Task _Main(GitHubClient github)
-        {
-            await MakePullRequest(github, remoteUser: "dotnet", myUser: "roslyn-bot", repoName: "roslyn", fromBranch: "master", intoBranch: "future");
-        }
-
-        static void PrintUsage()
-        {
-            Console.WriteLine("Usage:");
-            Console.WriteLine("    roslyn-merge-bot [auth-code]");
-            Console.WriteLine();
-            Console.WriteLine("If the auth-code parameter is not set, an environment variable named AUTH_CODE must be set.");
-        }
-
-        static int Main(string[] args)
-        {
-            string auth = null;
-            if (args.Length == 1)
+            if (options.Debug)
             {
-                if (args[0] == "--help" || args[0] == "/help")
-                {
-                    PrintUsage();
-                    return 0;
-                }
-                auth = args[0];
+                WriteDebugLine($"Create PR with title: {prTitle}.");
+                WriteDebugLine($"Create PR with body:\r\n{prMessage}");
             }
             else
             {
-                auth = (string) Environment.GetEnvironmentVariables()["AUTH_CODE"];
+                await github.PullRequest.Create(
+                    owner: options.DestinationUser,
+                    name: options.RepoName,
+                    newPullRequest: new NewPullRequest(
+                        title: prTitle,
+                        head: $"{options.SourceUser}:{newBranchName}",
+                        baseRef: options.DestinationBranch)
+                        {
+                            Body = prMessage
+                        }
+                    );
             }
+        }
 
-            if (auth != null) {
-                var github = new GitHubClient(new ProductHeaderValue("roslyn-bot"));
-                github.Credentials = new Credentials(auth);
-                _Main(github).GetAwaiter().GetResult();
-                return 0;
-            }
-            else
-            {
-                PrintUsage();
-                return 1;
-            }
+        private void WriteDebugLine(string line)
+        {
+            Console.WriteLine("Debug: " + line);
         }
     }
 }

src/Tools/Github/GitMergeBot/packages.config

 <?xml version="1.0" encoding="utf-8"?>
 <packages>
+  <package id="Mono.Options" version="1.1" targetFramework="net452" />
   <package id="Octokit" version="0.17.0" targetFramework="net452" />
 </packages>
\ No newline at end of file