Enable custom merge message formats via configuration

docs/configuration.md

@@ -48,6 +48,7 @@ commit-date-format: 'yyyy-MM-dd'
 ignore:
   sha: []
   commits-before: yyyy-MM-ddTHH:mm:ss
+merge-messages: {}
 ```
 
 And the description of the available options are:
@@ -179,6 +180,24 @@ Date and time in the format `yyyy-MM-ddTHH:mm:ss` (eg `commits-before:
 2015-10-23T12:23:15`) to setup an exclusion range. Effectively any commit before
 `commits-before` will be ignored.
 
+### merge-messages
+Custom merge message formats to enable identification of merge messages that do not
+follow the built-in conventions.  Entries should be added as key-value pairs where
+the value is a regular expression.
+e.g.
+
+```
+merge-messages:
+    tfs: ^Merged (?:PR (?<PullRequestNumber>\d+)): Merge (?<SourceBranch>.+) to (?<TargetBranch>.+)
+```
+
+The regular expression should contain the following capture groups:
++ SourceBranch - Identifies the source branch of the merge
++ TargetBranch - Identifies the target of the merge
++ PullRequestNumber - Captures the pull-request number
+
+Custom merge message formats are evalauted _before_ any built in formats.
+
 ## Branch configuration
 Then we have branch specific configuration, which looks something like this:
 

src/GitVersionCore.Tests/ConfigProviderTests.CanWriteOutEffectiveConfiguration.approved.txt

@@ -122,3 +122,4 @@ branches:
 ignore:
   sha: []
 commit-date-format: yyyy-MM-dd
+merge-messages: {}

src/GitVersionCore.Tests/Init/InitScenarios.CanSetNextVersion.approved.txt

@@ -2,3 +2,4 @@ next-version: 2.0.0
 branches: {}
 ignore:
   sha: []
+merge-messages: {}

src/GitVersionCore.Tests/MergeMessageTests.cs

@@ -2,6 +2,7 @@
 using NUnit.Framework;
 using Shouldly;
 using System;
+using System.Collections.Generic;
 
 namespace GitVersionCore.Tests
 {
@@ -228,15 +229,15 @@ public void ParsesTfsEnglishUSMessage(
             var sut = new MergeMessage(message, _config);
 
             // Assert
-            sut.MatchDefinition.ShouldBe("TfsMergeMessageEnglishUS");
+              sut.MatchDefinition.ShouldBe("TfsMergeMessageEnglishUS");
             sut.TargetBranch.ShouldBe(expectedTargetBranch);
             sut.MergedBranch.ShouldBe(expectedMergedBranch);
             sut.IsMergedPullRequest.ShouldBeFalse();
             sut.PullRequestNumber.ShouldBeNull();
             sut.Version.ShouldBe(expectedVersion);
         }
 
-        private static readonly object[] ParsesTfsGermanDEMergeMessages =
+private static readonly object[] ParsesTfsGermanDEMergeMessages =
         {
             new object[] { "Zusammengeführter PR \"1234\": feature/one mit master mergen", "feature/one", "master", null, 1234 },
             new object[] { "Zusammengeführter PR \"1234\": v://10.10.10.10 mit master mergen", "v://10.10.10.10", "master", null, 1234 },
@@ -291,5 +292,105 @@ public void ParsesInvalidMergeMessage(
             sut.PullRequestNumber.ShouldBe(expectedPullRequestNumber);
             sut.Version.ShouldBe(expectedVersion);
         }
+
+        [Test]
+        public void MatchesSingleCustomMessage()
+        {
+            // Arrange
+            var message = "My custom message";
+            var definition = "Mycustom";
+            _config.MergeMessageFormats = new Dictionary<string, string>
+            {
+                [definition] = message
+            };
+
+            // Act
+            var sut = new MergeMessage(message, _config);
+
+            // Assert
+            sut.MatchDefinition.ShouldBe(definition);
+            sut.TargetBranch.ShouldBeNull();
+            sut.MergedBranch.ShouldBeEmpty();
+            sut.IsMergedPullRequest.ShouldBeFalse();
+            sut.PullRequestNumber.ShouldBeNull();
+            sut.Version.ShouldBeNull();
+        }
+
+        [Test]
+        public void MatchesMultipleCustomMessages()
+        {
+            // Arrange
+            var format = "My custom message";
+            var definition = "Mycustom";
+            _config.MergeMessageFormats = new Dictionary<string, string>
+            {
+                ["Default2"] = "some example",
+                ["Default3"] = "another example",
+                [definition] = format
+            };
+
+            // Act
+            var sut = new MergeMessage(format, _config);
+
+            // Assert
+            sut.MatchDefinition.ShouldBe(definition);
+            sut.TargetBranch.ShouldBeNull();
+            sut.MergedBranch.ShouldBeEmpty();
+            sut.IsMergedPullRequest.ShouldBeFalse();
+            sut.PullRequestNumber.ShouldBeNull();
+            sut.Version.ShouldBeNull();
+        }
+
+        [Test]
+        public void MatchesCaptureGroupsFromCustomMessages()
+        {
+            // Arrange
+            var format = @"^Merged PR #(?<PullRequestNumber>\d+) into (?<TargetBranch>[^\s]*) from (?:(?<SourceBranch>[^\s]*))";
+            var definition = "Mycustom";
+            _config.MergeMessageFormats = new Dictionary<string, string>
+            {
+                [definition] = format
+            };
+            var pr = 1234;
+            var target = "master";
+            var source = "feature/2.0/example";
+
+
+            // Act
+            var sut = new MergeMessage($"Merged PR #{pr} into {target} from {source}", _config);
+
+            // Assert
+            sut.MatchDefinition.ShouldBe(definition);
+            sut.TargetBranch.ShouldBe(target);
+            sut.MergedBranch.ShouldBe(source);
+            sut.IsMergedPullRequest.ShouldBeTrue();
+            sut.PullRequestNumber.ShouldBe(pr);
+            sut.Version.ShouldBe(new SemanticVersion(2, 0));
+        }
+
+        [Test]
+        public void ReturnsAfterFirstMatchingPattern()
+        {
+            // Arrange
+            var format = @"^Merge (branch|tag) '(?<SourceBranch>[^']*)'(?: into (?<TargetBranch>[^\s]*))*";
+            var definition = "Mycustom";
+            _config.MergeMessageFormats = new Dictionary<string, string>
+            {
+                [definition] = format,
+                ["Default2"] = format,
+                ["Default3"] = format
+            };
+
+            // Act
+            var sut = new MergeMessage("Merge branch 'this'", _config);
+
+            // Assert
+            sut.MatchDefinition.ShouldBe(definition);
+            sut.TargetBranch.ShouldBeNull();
+            sut.MergedBranch.ShouldBe("this");
+            sut.IsMergedPullRequest.ShouldBeFalse();
+            sut.PullRequestNumber.ShouldBeNull();
+            sut.Version.ShouldBeNull();
+        }
     }
 }

src/GitVersionCore/Configuration/Config.cs

@@ -145,5 +145,8 @@ T MergeObjects<T>(T target, T source)
 
         [YamlMember(Alias = "commit-date-format")]
         public string CommitDateFormat { get; set; }
+
+        [YamlMember(Alias = "merge-messages")]
+        public Dictionary<string, string> MergeMessageFormats { get; set; } = new Dictionary<string, string>();
     }
 }

src/GitVersionCore/MergeMessage.cs

@@ -4,56 +4,74 @@
 
 namespace GitVersion
 {
-    class MergeMessage
+    public class MergeMessage
     {
-        private static readonly IList<MergeMessagePattern> Patterns = new List<MergeMessagePattern>
+        private static readonly IList<KeyValuePair<string, Regex>> DefaultPatterns = new List<KeyValuePair<string, Regex>>
         {
-            new MergeMessagePattern("Default", @"^Merge (branch|tag) '(?<SourceBranch>[^']*)'(?: into (?<TargetBranch>[^\s]*))*"),
-            new MergeMessagePattern("SmartGit",  @"^Finish (?<SourceBranch>[^\s]*)(?: into (?<TargetBranch>[^\s]*))*"),
-            new MergeMessagePattern("BitBucketPull", @"^Merge pull request #(?<PullRequestNumber>\d+) (from|in) (?<Source>.*) from (?<SourceBranch>[^\s]*) to (?<TargetBranch>[^\s]*)"),
-            new MergeMessagePattern("GitHubPull", @"^Merge pull request #(?<PullRequestNumber>\d+) (from|in) (?:(?<SourceBranch>[^\s]*))(?: into (?<TargetBranch>[^\s]*))*"),
-            new MergeMessagePattern("RemoteTracking", @"^Merge remote-tracking branch '(?<SourceBranch>[^\s]*)'(?: into (?<TargetBranch>[^\s]*))*"),
-            new MergeMessagePattern("TfsMergeMessageEnglishUS", @"^Merge (?<SourceBranch>[^\s]*) to (?<TargetBranch>[^\s]*)"),
-            new MergeMessagePattern("TfsMergeMessageGermanDE",@"^Zusammengeführter PR ""(?<PullRequestNumber>\d+)""\: (?<SourceBranch>.*) mit (?<TargetBranch>.*) mergen")
+            Pattern("Default", @"^Merge (branch|tag) '(?<SourceBranch>[^']*)'(?: into (?<TargetBranch>[^\s]*))*"),
+            Pattern("SmartGit",  @"^Finish (?<SourceBranch>[^\s]*)(?: into (?<TargetBranch>[^\s]*))*"),
+            Pattern("BitBucketPull", @"^Merge pull request #(?<PullRequestNumber>\d+) (from|in) (?<Source>.*) from (?<SourceBranch>[^\s]*) to (?<TargetBranch>[^\s]*)"),
+            Pattern("GitHubPull", @"^Merge pull request #(?<PullRequestNumber>\d+) (from|in) (?:(?<SourceBranch>[^\s]*))(?: into (?<TargetBranch>[^\s]*))*"),
+            Pattern("RemoteTracking", @"^Merge remote-tracking branch '(?<SourceBranch>[^\s]*)'(?: into (?<TargetBranch>[^\s]*))*"),
+            Pattern("TfsMergeMessageEnglishUS", @"^Merge (?<SourceBranch>[^\s]*) to (?<TargetBranch>[^\s]*)"),
+            Pattern("TfsMergeMessageGermanDE",@"^Zusammengeführter PR ""(?<PullRequestNumber>\d+)""\: (?<SourceBranch>.*) mit (?<TargetBranch>.*) mergen")
         };
 
         public MergeMessage(string mergeMessage, Config config)
         {
             if (mergeMessage == null)
                 throw new NullReferenceException();
 
-            foreach (var pattern in Patterns)
+            foreach(var entry in config.MergeMessageFormats)
             {
-                var match = pattern.Format.Match(mergeMessage);
-                if (match.Success)
+                var pattern = Pattern(entry.Key, entry.Value);
+                if (ApplyPattern(mergeMessage, config.TagPrefix, pattern))
                 {
-                    MatchDefinition = pattern.Name;
-                    MergedBranch = match.Groups["SourceBranch"].Value;
-
-                    if (match.Groups["TargetBranch"].Success)
-                    {
-                        TargetBranch = match.Groups["TargetBranch"].Value;
-                    }
-
-                    if (int.TryParse(match.Groups["PullRequestNumber"].Value, out var pullNumber))
-                    {
-                        PullRequestNumber = pullNumber;
-                    }
-
-                    Version = ParseVersion(MergedBranch, config.TagPrefix);
+                    return;
+                }
+            }
 
-                    break;
+            foreach (var pattern in DefaultPatterns)
+            {
+                if (ApplyPattern(mergeMessage, config.TagPrefix, pattern))
+                {
+                    return;
                 }
             }
         }
 
-        public string MatchDefinition { get; }
-        public string TargetBranch { get; }
-        public string MergedBranch { get; } = "";
+        public string MatchDefinition { get; private set; }
+        public string TargetBranch { get; private set; }
+        public string MergedBranch { get; private set; } = "";
         public bool IsMergedPullRequest => PullRequestNumber != null;
-        public int? PullRequestNumber { get; }
-        public SemanticVersion Version { get; }
+        public int? PullRequestNumber { get; private set; }
+        public SemanticVersion Version { get; private set; }
+
+        private bool ApplyPattern(string mergeMessage, string tagPrefix, KeyValuePair<string, Regex> pattern)
+        {
+            var match = pattern.Value.Match(mergeMessage);
+            if (match.Success)
+            {
+                MatchDefinition = pattern.Key;
+                MergedBranch = match.Groups["SourceBranch"].Value;
+
+                if (match.Groups["TargetBranch"].Success)
+                {
+                    TargetBranch = match.Groups["TargetBranch"].Value;
+                }
 
+                if (int.TryParse(match.Groups["PullRequestNumber"].Value, out var pullNumber))
+                {
+                    PullRequestNumber = pullNumber;
+                }
+
+                Version = ParseVersion(MergedBranch, tagPrefix);
+
+                return true;
+            }
+
+            return false;
+        }
 
         private SemanticVersion ParseVersion(string branchName, string tagPrefix)
         {
@@ -72,17 +90,7 @@ private SemanticVersion ParseVersion(string branchName, string tagPrefix)
             return null;
         }
 
-        private class MergeMessagePattern
-        {
-            public MergeMessagePattern(string name, string format)
-            {
-                Name = name;
-                Format = new Regex(format, RegexOptions.IgnoreCase | RegexOptions.Compiled);
-            }
-
-            public string Name { get; }
-
-            public Regex Format { get; }
-        }
+        private static KeyValuePair<string, Regex> Pattern(string name, string format)
+            => new KeyValuePair<string, Regex>(name, new Regex(format, RegexOptions.IgnoreCase | RegexOptions.Compiled));
     }
 }