(#112) Add new method for creating empty release

This is similar to the overload for passing in an input file, the
difference being that string.Empty is passed in, rather than reading
the contents of the file, and then creating a release.

Author: gep13

src/GitReleaseManager.Core.Tests/Commands/CreateCommandTests.cs

@@ -27,6 +27,31 @@ public void Setup()
             _command = new CreateCommand(_vcsService, _logger);
         }
 
+        public async Task Should_Create_Empty_Release()
+        {
+            var options = new CreateSubOptions
+            {
+                RepositoryOwner = "owner",
+                RepositoryName = "repository",
+                TargetCommitish = "target commitish",
+                Prerelease = false,
+                AllowEmpty = true,
+            };
+
+            var releaseName = options.Name ?? options.Milestone;
+
+            _vcsService.CreateEmptyReleaseAsync(options.RepositoryOwner, options.RepositoryName, options.Name, options.TargetCommitish, options.Prerelease)
+                .Returns(_release);
+
+            var result = await _command.Execute(options).ConfigureAwait(false);
+            result.ShouldBe(0);
+
+            await _vcsService.Received(1).CreateEmptyReleaseAsync(options.RepositoryOwner, options.RepositoryName, releaseName, options.TargetCommitish, options.Prerelease).ConfigureAwait(false);
+            _logger.Received(1).Information(Arg.Any<string>());
+            _logger.Received(1).Information(Arg.Any<string>(), _release.HtmlUrl);
+            _logger.Received(1).Verbose(Arg.Any<string>(), _release.Body);
+        }
+
         [TestCase(null, 2)]
         [TestCase("release", 1)]
         public async Task Should_Create_Release_From_Milestone(string name, int logVerboseCount)

src/GitReleaseManager.Core/Commands/CreateCommand.cs

@@ -22,7 +22,12 @@ public async Task<int> Execute(CreateSubOptions options)
 
             Release release;
 
-            if (!string.IsNullOrEmpty(options.Milestone))
+            if (options.AllowEmpty)
+            {
+                _logger.Verbose("The AllowEmpty option has been passed, so an empty release will now be created");
+                release = await _vcsService.CreateEmptyReleaseAsync(options.RepositoryOwner, options.RepositoryName, options.Name, options.TargetCommitish, options.Prerelease).ConfigureAwait(false);
+            }
+            else if (!string.IsNullOrEmpty(options.Milestone))
             {
                 _logger.Verbose("Milestone {Milestone} was specified", options.Milestone);
                 var releaseName = options.Name;

src/GitReleaseManager.Core/IVcsService.cs

@@ -6,6 +6,8 @@ namespace GitReleaseManager.Core
 {
     public interface IVcsService
     {
+        Task<Release> CreateEmptyReleaseAsync(string owner, string repository, string name, string targetCommitish, bool prerelease);
+
         Task<Release> CreateReleaseFromMilestoneAsync(string owner, string repository, string milestone, string releaseName, string targetCommitish, IList<string> assets, bool prerelease, string templateFilePath);
 
         Task<Release> CreateReleaseFromInputFileAsync(string owner, string repository, string name, string inputFilePath, string targetCommitish, IList<string> assets, bool prerelease);

src/GitReleaseManager.Core/Options/CreateSubOptions.cs

@@ -26,5 +26,8 @@ public class CreateSubOptions : BaseVcsOptions
 
         [Option('e', "pre", Required = false, HelpText = "Creates the release as a pre-release.")]
         public bool Prerelease { get; set; }
+
+        [Option("allowEmpty", Required = false, HelpText = "Allow the creation of an empty set of release notes. In this mode, milestone and input file path will be ignored.")]
+        public bool AllowEmpty { get; set; }
     }
 }

src/GitReleaseManager.Core/VcsService.cs

@@ -37,6 +37,12 @@ public VcsService(IVcsProvider vcsProvider, ILogger logger, IReleaseNotesBuilder
             _configuration = configuration;
         }
 
+        public async Task<Release> CreateEmptyReleaseAsync(string owner, string repository, string name, string targetCommitish, bool prerelease)
+        {
+            var release = await CreateReleaseAsync(owner, repository, name, name, string.Empty, prerelease, targetCommitish, null).ConfigureAwait(false);
+            return release;
+        }
+
         public async Task<Release> CreateReleaseFromMilestoneAsync(string owner, string repository, string milestone, string releaseName, string targetCommitish, IList<string> assets, bool prerelease, string templateFilePath)
         {
             var templatePath = ReleaseTemplates.DEFAULT_NAME;

src/GitReleaseManager.Tests/VcsServiceMock.cs

@@ -25,6 +25,11 @@ public VcsServiceMock()
 
         public int NumberOfCommits { get; set; }
 
+        public Task<Release> CreateEmptyReleaseAsync(string owner, string repository, string name, string targetCommitish, bool prerelease)
+        {
+            throw new System.NotImplementedException();
+        }
+
         public Task<Release> CreateReleaseFromMilestoneAsync(string owner, string repository, string milestone, string releaseName, string targetCommitish, IList<string> assets, bool prerelease, string templateFilePath)
         {
             throw new System.NotImplementedException();