Add HEAD support

docs/input/docs/reference/configuration.md

@@ -552,6 +552,11 @@ Example of invalid `Strict`, but valid `Loose`
 1.2.3.4
 ```
 
+### handle-detached-branch
+
+Avoid to strickly request to refer to a branch. If detached, the `no-branch`
+reference will be used.
+
 [1145]: https://github.com/GitTools/GitVersion/issues/1145
 [1366]: https://github.com/GitTools/GitVersion/issues/1366
 [2506]: https://github.com/GitTools/GitVersion/pull/2506#issuecomment-754754037

src/GitVersion.Core.Tests/Configuration/ConfigurationProviderTests.CanWriteOutEffectiveConfiguration.approved.txt

@@ -109,3 +109,4 @@ increment: Inherit
 commit-date-format: yyyy-MM-dd
 merge-message-formats: {}
 update-build-number: true
+handle-detached-branch: false

src/GitVersion.Core.Tests/Helpers/GitFlowConfigurationBuilder.cs

@@ -24,6 +24,7 @@ private GitFlowConfigurationBuilder()
             CommitDateFormat = "yyyy-MM-dd",
             UpdateBuildNumber = true,
             SemanticVersionFormat = SemanticVersionFormat.Strict,
+            HandleDetachedBranch = false,
             TagPreReleaseWeight = 60000,
             Increment = IncrementStrategy.Inherit
         });

src/GitVersion.Core.Tests/Helpers/GitHubFlowConfigurationBuilder.cs

@@ -24,6 +24,7 @@ private GitHubFlowConfigurationBuilder()
             CommitDateFormat = "yyyy-MM-dd",
             UpdateBuildNumber = true,
             SemanticVersionFormat = SemanticVersionFormat.Strict,
+            HandleDetachedBranch = false,
             TagPreReleaseWeight = 60000,
             Increment = IncrementStrategy.Inherit
         });

src/GitVersion.Core.Tests/Helpers/TestConfigurationBuilderBase.cs

@@ -27,6 +27,7 @@ internal abstract class TestConfigurationBuilderBase<TConfigurationBuilder>
     private string? commitDateFormat;
     private bool? updateBuildNumber;
     private SemanticVersionFormat semanticVersionFormat = SemanticVersionFormat.Strict;
+    private bool? handleDetachedBranch;
     private Dictionary<string, string>? mergeMessageFormats;
     protected readonly Dictionary<string, TestBranchConfigurationBuilder> branchConfigurationBuilders = new();
 
@@ -164,6 +165,12 @@ public virtual TConfigurationBuilder WithSemanticVersionFormat(SemanticVersionFo
         return (TConfigurationBuilder)this;
     }
 
+    public virtual TConfigurationBuilder WithHandleDetachedBranch(bool? value)
+    {
+        this.handleDetachedBranch = value;
+        return (TConfigurationBuilder)this;
+    }
+
     public virtual TConfigurationBuilder WithMergeMessageFormats(Dictionary<string, string> value)
     {
         this.mergeMessageFormats = value;
@@ -214,6 +221,7 @@ public virtual TConfigurationBuilder WithConfiguration(GitVersionConfiguration v
         WithCommitDateFormat(value.CommitDateFormat);
         WithUpdateBuildNumber(value.UpdateBuildNumber);
         WithSemanticVersionFormat(value.SemanticVersionFormat);
+        WithHandleDetachedBranch(value.HandleDetachedBranch);
         WithMergeMessageFormats(value.MergeMessageFormats);
         foreach (var (name, branchConfiguration) in value.Branches)
         {
@@ -246,6 +254,7 @@ public virtual GitVersionConfiguration Build()
             CommitDateFormat = this.commitDateFormat,
             UpdateBuildNumber = this.updateBuildNumber,
             SemanticVersionFormat = this.semanticVersionFormat,
+            HandleDetachedBranch = this.handleDetachedBranch,
             MergeMessageFormats = this.mergeMessageFormats ?? new()
         };
         Dictionary<string, BranchConfiguration> branches = new();

src/GitVersion.Core.Tests/IntegrationTests/RemoteRepositoryScenarios.cs

@@ -1,5 +1,6 @@
 using GitTools.Testing;
 using GitVersion.BuildAgents;
+using GitVersion.Configuration;
 using GitVersion.Core.Tests.Helpers;
 using LibGit2Sharp;
 using Microsoft.Extensions.DependencyInjection;
@@ -98,6 +99,24 @@ public void GivenARemoteGitRepositoryWhenCheckingOutDetachedHeadUsingExistingImp
             $"It looks like the branch being examined is a detached Head pointing to commit '{fixture.LocalRepositoryFixture.Repository.Head.Tip.Id.ToString(7)}'. Without a proper branch name GitVersion cannot determine the build version.");
     }
 
+    [Test]
+    [TestCase(true)]
+    [TestCase(false)]
+    public void GivenARemoteGitRepositoryWhenCheckingOutDetachedHeadUsingExistingImplementationHandleDetachedBranch(bool handleDetachedBranch)
+    {
+        using var fixture = new RemoteRepositoryFixture();
+        Commands.Checkout(
+            fixture.LocalRepositoryFixture.Repository,
+            fixture.LocalRepositoryFixture.Repository.Head.Tip);
+
+        var configuration = new GitVersionConfiguration { HandleDetachedBranch = handleDetachedBranch };
+        if (handleDetachedBranch)
+            fixture.AssertFullSemver("0.0.1--no-branch-.1+5", configuration: configuration, repository: fixture.LocalRepositoryFixture.Repository, onlyTrackedBranches: false);
+        else
+            Should.Throw<WarningException>(() => fixture.AssertFullSemver("0.1.0+4", repository: fixture.LocalRepositoryFixture.Repository, onlyTrackedBranches: false),
+                $"It looks like the branch being examined is a detached Head pointing to commit '{fixture.LocalRepositoryFixture.Repository.Head.Tip.Id.ToString(7)}'. Without a proper branch name GitVersion cannot determine the build version.");
+    }
+
     [Test]
     [Ignore("Needs more investigations.")]
     public void GivenARemoteGitRepositoryWhenCheckingOutDetachedHeadUsingTrackingBranchOnlyBehaviourShouldReturnVersion014Plus5()

src/GitVersion.Core/Configuration/ConfigurationBuilder.cs

@@ -54,6 +54,7 @@ private static void ApplyOverrides(GitVersionConfiguration targetConfig, GitVers
         targetConfig.MergeMessageFormats = overrideConfiguration.MergeMessageFormats.Any() ? overrideConfiguration.MergeMessageFormats : targetConfig.MergeMessageFormats;
         targetConfig.UpdateBuildNumber = overrideConfiguration.UpdateBuildNumber ?? targetConfig.UpdateBuildNumber;
         targetConfig.SemanticVersionFormat = overrideConfiguration.SemanticVersionFormat;
+        targetConfig.HandleDetachedBranch = overrideConfiguration.HandleDetachedBranch ?? targetConfig.HandleDetachedBranch;
 
         if (overrideConfiguration.Ignore is { IsEmpty: false })
         {
@@ -187,6 +188,7 @@ private static GitVersionConfiguration CreateDefaultConfiguration()
             CommitDateFormat = "yyyy-MM-dd",
             UpdateBuildNumber = true,
             SemanticVersionFormat = SemanticVersionFormat.Strict,
+            HandleDetachedBranch = false,
             TagPreReleaseWeight = DefaultTagPreReleaseWeight,
             Increment = IncrementStrategy.Inherit
         };

src/GitVersion.Core/Configuration/GitVersionConfiguration.cs

@@ -88,6 +88,9 @@ public string? NextVersion
     [YamlMember(Alias = "semver-format")]
     public SemanticVersionFormat SemanticVersionFormat { get; set; } = SemanticVersionFormat.Strict;
 
+    [YamlMember(Alias = "handle-detached-branch")]
+    public bool? HandleDetachedBranch { get; set; }
+
     public override string ToString()
     {
         var stringBuilder = new StringBuilder();

src/GitVersion.Core/Core/Abstractions/IRepositoryStore.cs

@@ -38,7 +38,7 @@ public interface IRepositoryStore
 
     IEnumerable<IBranch> GetSourceBranches(IBranch branch, GitVersionConfiguration configuration, IEnumerable<IBranch> excludedBranches);
 
-    SemanticVersion? GetCurrentCommitTaggedVersion(ICommit? commit, string? tagPrefix);
+    SemanticVersion? GetCurrentCommitTaggedVersion(ICommit? commit, GitVersionConfiguration configuration);
 
     IEnumerable<SemanticVersion> GetVersionTagsOnBranch(IBranch branch, string? tagPrefixRegex);
     IEnumerable<(ITag Tag, SemanticVersion Semver, ICommit Commit)> GetValidVersionTags(string? tagPrefixRegex, DateTimeOffset? olderThan = null);

src/GitVersion.Core/Core/GitVersionContextFactory.cs

@@ -33,7 +33,7 @@ public GitVersionContext Create(GitVersionOptions gitVersionOptions)
             currentBranch = branchForCommit ?? currentBranch;
         }
 
-        var currentCommitTaggedVersion = this.repositoryStore.GetCurrentCommitTaggedVersion(currentCommit, configuration.TagPrefix);
+        var currentCommitTaggedVersion = this.repositoryStore.GetCurrentCommitTaggedVersion(currentCommit, configuration);
         var numberOfUncommittedChanges = this.repositoryStore.GetNumberOfUncommittedChanges();
 
         return new GitVersionContext(currentBranch, currentCommit, configuration, currentCommitTaggedVersion, numberOfUncommittedChanges);

src/GitVersion.Core/Core/RepositoryStore.cs

@@ -146,17 +146,16 @@ public IEnumerable<IBranch> GetSourceBranches(IBranch branch, GitVersionConfigur
         var referenceLookup = this.repository.Refs.ToLookup(r => r.TargetIdentifier);
 
         var returnedBranches = new HashSet<IBranch>();
-        if (referenceLookup.Any())
+        if (!referenceLookup.Any())
+            yield break;
+        foreach (var branchCommit in FindCommitBranchesWasBranchedFrom(branch, configuration, excludedBranches))
         {
-            foreach (var branchCommit in FindCommitBranchesWasBranchedFrom(branch, configuration, excludedBranches))
+            foreach (var _ in referenceLookup[branchCommit.Commit.Sha]
+                         .Where(r => r.Name.Friendly == branchCommit.Branch.Name.Friendly))
             {
-                foreach (var _ in referenceLookup[branchCommit.Commit.Sha]
-                    .Where(r => r.Name.Friendly == branchCommit.Branch.Name.Friendly))
+                if (returnedBranches.Add(branchCommit.Branch))
                 {
-                    if (returnedBranches.Add(branchCommit.Branch))
-                    {
-                        yield return branchCommit.Branch;
-                    }
+                    yield return branchCommit.Branch;
                 }
             }
         }
@@ -219,9 +218,9 @@ public IEnumerable<BranchCommit> FindCommitBranchesWasBranchedFrom(IBranch branc
         }
     }
 
-    public SemanticVersion? GetCurrentCommitTaggedVersion(ICommit? commit, string? tagPrefix)
+    public SemanticVersion? GetCurrentCommitTaggedVersion(ICommit? commit, GitVersionConfiguration configuration)
         => this.repository.Tags
-            .SelectMany(t => GetCurrentCommitSemanticVersions(commit, tagPrefix, t))
+            .SelectMany(t => GetCurrentCommitSemanticVersions(commit, configuration.TagPrefix, t, configuration.HandleDetachedBranch ?? false))
             .Max();
 
     public IEnumerable<SemanticVersion> GetVersionTagsOnBranch(IBranch branch, string? tagPrefixRegex)
@@ -290,12 +289,17 @@ public bool IsCommitOnBranch(ICommit? baseVersionSource, IBranch branch, ICommit
     private static bool IsReleaseBranch(INamedReference branch, IEnumerable<KeyValuePair<string, BranchConfiguration>> releaseBranchConfig)
         => releaseBranchConfig.Any(c => c.Value?.Regex != null && Regex.IsMatch(branch.Name.Friendly, c.Value.Regex));
 
-    private static IEnumerable<SemanticVersion> GetCurrentCommitSemanticVersions(ICommit? commit, string? tagPrefix, ITag tag)
+    private IEnumerable<SemanticVersion> GetCurrentCommitSemanticVersions(ICommit? commit, string? tagPrefix, ITag tag, bool handleDetachedBranch)
     {
         var targetCommit = tag.PeeledTargetCommit();
+        if (targetCommit == null)
+            return Array.Empty<SemanticVersion>();
+
+        var commitToCompare = handleDetachedBranch ? FindMergeBase(commit, targetCommit) : commit;
+
         var tagName = tag.Name.Friendly;
 
-        return targetCommit != null && Equals(targetCommit, commit) && SemanticVersion.TryParse(tagName, tagPrefix, out var version)
+        return Equals(targetCommit, commitToCompare) && SemanticVersion.TryParse(tagName, tagPrefix, out var version)
             ? new[] { version }
             : Array.Empty<SemanticVersion>();
     }

src/GitVersion.Core/VersionCalculation/NextVersionCalculator.cs

@@ -133,7 +133,7 @@ private void UpdatePreReleaseTag(EffectiveBranchConfiguration configuration, Sem
 
     private static void EnsureHeadIsNotDetached(GitVersionContext context)
     {
-        if (context.CurrentBranch.IsDetachedHead != true)
+        if (context.CurrentBranch.IsDetachedHead != true || (context.Configuration.HandleDetachedBranch ?? false))
         {
             return;
         }