Allow inheriting of the parent branches increment strategy. Allows feature branches off develop or master to increment based off the develop or master increment strategy

Author: JakeGinnivan

GitVersionCore.Tests/GitVersionContextTests.cs

@@ -1,6 +1,7 @@
 namespace GitVersionCore.Tests
 {
     using GitVersion;
+    using LibGit2Sharp;
     using NUnit.Framework;
     using Shouldly;
 
@@ -50,5 +51,26 @@ public void UsesBranchSpecificConfigOverTopLevelDefaults()
             context.Configuration.VersioningMode.ShouldBe(VersioningMode.ContinuousDeployment);
             context.Configuration.Tag.ShouldBe("alpha");
         }
+
+        [Test]
+        public void CanFindParentBranchForInheritingIncrementStrategy()
+        {
+            var config = new Config();
+            config.Branches["develop"].Increment = IncrementStrategy.Major;
+            config.Branches["feature[/-]"].Increment = IncrementStrategy.Inherit;
+
+            using (var repo = new EmptyRepositoryFixture(config))
+            {
+                repo.Repository.MakeACommit();
+                repo.Repository.CreateBranch("develop").Checkout();
+                repo.Repository.MakeACommit();
+                var featureBranch = repo.Repository.CreateBranch("feature/foo");
+                featureBranch.Checkout();
+                repo.Repository.MakeACommit();
+
+                var context = new GitVersionContext(repo.Repository, featureBranch, config);
+                context.Configuration.Increment.ShouldBe(IncrementStrategy.Major);
+            }
+        }
     }
 }

GitVersionCore/BranchNameComparer.cs

@@ -0,0 +1,18 @@
+namespace GitVersion
+{
+    using System.Collections.Generic;
+    using LibGit2Sharp;
+
+    class BranchNameComparer : IEqualityComparer<Branch>
+    {
+        public bool Equals(Branch x, Branch y)
+        {
+            return x.Name == y.Name;
+        }
+
+        public int GetHashCode(Branch obj)
+        {
+            return obj.Name.GetHashCode();
+        }
+    }
+}

GitVersionCore/Configuration/BranchConfig.cs

@@ -4,6 +4,17 @@
 
     public class BranchConfig
     {
+        public BranchConfig()
+        {
+        }
+
+        public BranchConfig(BranchConfig branchConfiguration)
+        {
+            VersioningMode = branchConfiguration.VersioningMode;
+            Tag = branchConfiguration.Tag;
+            Increment = branchConfiguration.Increment;
+        }
+
         [YamlAlias("mode")]
         public VersioningMode? VersioningMode { get; set; }
 

GitVersionCore/Configuration/Config.cs

@@ -14,6 +14,10 @@ public Config()
             TagPrefix = "[vV]";
             VersioningMode = GitVersion.VersioningMode.ContinuousDelivery;
             Branches["release[/-]"] = new BranchConfig { Tag = "beta" };
+            Branches["feature[/-]"] = new BranchConfig
+            {
+                Increment = IncrementStrategy.Inherit,
+            };
             Branches["hotfix[/-]"] = new BranchConfig { Tag = "beta" };
             Branches["develop"] = new BranchConfig
             {

GitVersionCore/Configuration/IncrementStrategy.cs

@@ -5,6 +5,10 @@ public enum IncrementStrategy
         None,
         Major,
         Minor,
-        Patch
+        Patch,
+        /// <summary>
+        /// Uses the increment strategy from the branch the current branch was branched from
+        /// </summary>
+        Inherit 
     }
 }

GitVersionCore/GitVersionContext.cs

@@ -81,9 +81,7 @@ IEnumerable<Branch> GetBranchesContainingCommit(string commitSha)
 
         void CalculateEffectiveConfiguration()
         {
-            var matchingBranches = configuration.Branches.Where(b => Regex.IsMatch("^" + CurrentBranch.Name, b.Key)).ToArray();
-
-            var currentBranchConfig = GetBranchConfiguration(matchingBranches);
+            var currentBranchConfig = GetBranchConfiguration(CurrentBranch);
 
             var versioningMode = currentBranchConfig.VersioningMode ?? configuration.VersioningMode ?? VersioningMode.ContinuousDelivery;
             var tag = currentBranchConfig.Tag;
@@ -93,19 +91,58 @@ void CalculateEffectiveConfiguration()
             Configuration = new EffectiveConfiguration(configuration.AssemblyVersioningScheme, versioningMode, configuration.TagPrefix, tag, nextVersion, incrementStrategy);
         }
 
-        BranchConfig GetBranchConfiguration(KeyValuePair<string, BranchConfig>[] matchingBranches)
+        BranchConfig GetBranchConfiguration(Branch currentBranch)
         {
+            KeyValuePair<string, BranchConfig>[] matchingBranches = configuration.Branches.Where(b => Regex.IsMatch("^" + currentBranch.Name, b.Key)).ToArray();
+
             if (matchingBranches.Length == 0)
             {
                 return new BranchConfig();
             }
             if (matchingBranches.Length == 1)
             {
-                return matchingBranches[0].Value;
+                var branchConfiguration = matchingBranches[0].Value;
+
+                if (branchConfiguration.Increment == IncrementStrategy.Inherit)
+                {
+                    var firstCommitOfBranch = currentBranch.Commits.Last();
+                    var parentCommit = Repository.Commits.QueryBy(new CommitFilter
+                    {
+                        Until = firstCommitOfBranch
+                    }).First().Parents.First();
+                    var branchesContainingFirstCommit = ListBranchesContaininingCommit(Repository, firstCommitOfBranch.Sha);
+                    var branchesContainingParentCommit = ListBranchesContaininingCommit(Repository, parentCommit.Sha);
+
+                    var branchNameComparer = new BranchNameComparer();
+                    var possibleParents = branchesContainingFirstCommit
+                        .Intersect(branchesContainingParentCommit, branchNameComparer)
+                        .Except(new[] { currentBranch }, branchNameComparer)
+                        .ToArray();
+
+                    if (possibleParents.Length == 1)
+                    {
+                        return new BranchConfig(branchConfiguration)
+                        {
+                            Increment = GetBranchConfiguration(possibleParents[0]).Increment
+                        };
+                    }
+
+                    throw new Exception("Failed to inherit Increment branch configuration");
+                }
+
+                return branchConfiguration;
             }
 
-            const string format = "Multiple branch configurations match the current branch name of '{0}'. Matching configurations: '{1}'";
-            throw new Exception(string.Format(format, CurrentBranch.Name, string.Join(", ", matchingBranches.Select(b => b.Key))));
+            const string format = "Multiple branch configurations match the current branch branchName of '{0}'. Matching configurations: '{1}'";
+            throw new Exception(string.Format(format, currentBranch.Name, string.Join(", ", matchingBranches.Select(b => b.Key))));
+        }
+
+        static IEnumerable<Branch> ListBranchesContaininingCommit(IRepository repo, string commitSha)
+        {
+            return from branch in repo.Branches
+                   let commits = repo.Commits.QueryBy(new CommitFilter { Since = branch }).Where(c => c.Sha == commitSha)
+                   where commits.Any()
+                   select branch;
         }
     }
 }

GitVersionCore/GitVersionCore.csproj

@@ -62,6 +62,7 @@
     <Compile Include="AssemblyVersioningScheme.cs" />
     <Compile Include="AssemblyVersionsGenerator.cs" />
     <Compile Include="Authentication.cs" />
+    <Compile Include="BranchNameComparer.cs" />
     <Compile Include="BuildServers\AppVeyor.cs" />
     <Compile Include="BuildServers\BuildServerBase.cs" />
     <Compile Include="BuildServers\BuildServerList.cs" />