GH2282: Check early for commit on current branch

src/GitVersionCore.Tests/Core/GitVersionExecutorTests.cs

@@ -391,7 +391,22 @@ public void WorkingDirectoryWithoutGit()
                 var gitVersionCalculator = GetGitVersionCalculator(gitVersionOptions);
                 gitVersionCalculator.CalculateVersionVariables();
             });
-            exception.Message.ShouldContain("Can't find the .git directory in");
+            exception.Message.ShouldContain("Cannot find the .git directory");
+        }
+
+        [Test]
+        public void WorkingDirectoryWithoutCommits()
+        {
+            using var fixture = new EmptyRepositoryFixture();
+
+            var gitVersionOptions = new GitVersionOptions { WorkingDirectory = fixture.RepositoryPath };
+
+            var exception = Assert.Throws<GitVersionException>(() =>
+            {
+                var gitVersionCalculator = GetGitVersionCalculator(gitVersionOptions);
+                gitVersionCalculator.CalculateVersionVariables();
+            });
+            exception.Message.ShouldContain("No commits found on the current branch.");
         }
 
         [Test]

src/GitVersionCore/Extensions/GitVersionOptionsExtensions.cs

@@ -15,7 +15,7 @@ public static string GetDotGitDirectory(this GitVersionOptions gitVersionOptions
 
             dotGitDirectory = dotGitDirectory?.TrimEnd('/', '\\');
             if (string.IsNullOrEmpty(dotGitDirectory))
-                throw new DirectoryNotFoundException($"Can't find the .git directory in {dotGitDirectory}");
+                throw new DirectoryNotFoundException("Cannot find the .git directory");
 
             return dotGitDirectory.Contains(Path.Combine(".git", "worktrees"))
                 ? Directory.GetParent(Directory.GetParent(dotGitDirectory).FullName).FullName
@@ -32,7 +32,7 @@ public static string GetProjectRootDirectory(this GitVersionOptions gitVersionOp
             var dotGitDirectory = Repository.Discover(gitVersionOptions.WorkingDirectory);
 
             if (string.IsNullOrEmpty(dotGitDirectory))
-                throw new DirectoryNotFoundException($"Can't find the .git directory in {dotGitDirectory}");
+                throw new DirectoryNotFoundException("Cannot find the .git directory");
 
             using var repository = new Repository(dotGitDirectory);
             return repository.Info.WorkingDirectory;

src/GitVersionCore/VersionCalculation/BaseVersionCalculators/FallbackVersionStrategy.cs

@@ -22,14 +22,18 @@ public override IEnumerable<BaseVersion> GetVersions()
         {
             Commit baseVersionSource;
             var currentBranchTip = Context.CurrentBranch.Tip;
+            if (currentBranchTip == null)
+            {
+                throw new GitVersionException("No commits found on the current branch.");
+            }
 
             try
             {
                 baseVersionSource = repositoryMetadataProvider.GetBaseVersionSource(currentBranchTip);
             }
             catch (NotFoundException exception)
             {
-                throw new GitVersionException($"Can't find commit {currentBranchTip.Sha}. Please ensure that the repository is an unshallow clone with `git fetch --unshallow`.", exception);
+                throw new GitVersionException($"Cannot find commit {currentBranchTip.Sha}. Please ensure that the repository is an unshallow clone with `git fetch --unshallow`.", exception);
             }
 
             yield return new BaseVersion("Fallback base version", false, new SemanticVersion(minor: 1), baseVersionSource, null);

src/GitVersionExe.Tests/ExecCmdLineArgumentTest.cs

@@ -77,7 +77,18 @@ public void WorkingDirectoryWithoutGitFolderFailsWithInformativeMessage()
             var result = GitVersionHelper.ExecuteIn(Environment.SystemDirectory, arguments: null, logToFile: false);
 
             result.ExitCode.ShouldNotBe(0);
-            result.Output.ShouldContain("Can't find the .git directory in");
+            result.Output.ShouldContain("Cannot find the .git directory");
+        }
+
+        [Test]
+        public void WorkingDirectoryWithoutCommitsFailsWithInformativeMessage()
+        {
+            using var fixture = new EmptyRepositoryFixture();
+
+            var result = GitVersionHelper.ExecuteIn(fixture.RepositoryPath, arguments: null, logToFile: false);
+
+            result.ExitCode.ShouldNotBe(0);
+            result.Output.ShouldContain("No commits found on the current branch.");
         }
 
         [Test]