fix: Cannot create commit with Repository mock on existing branch

NGitLab.Mock.Tests/RepositoryMockTests.cs

@@ -0,0 +1,226 @@
+using System.Collections.Generic;
+using System.Net;
+using FluentAssertions;
+using NGitLab.Mock.Clients;
+using NGitLab.Models;
+using NUnit.Framework;
+
+namespace NGitLab.Mock.Tests;
+
+public class RepositoryMockTests
+{
+    [Test]
+    public void Test_create_commit_in_new_branch_fails_if_both_start_branch_and_sha_specified()
+    {
+        // Arrange
+        using var server = new GitLabServer();
+        var user = server.Users.AddNew();
+        var project = user.Namespace.Projects.AddNew(project => project.Visibility = VisibilityLevel.Internal);
+        var initCommit = project.Repository.Commit(user, "Initial commit");
+
+        var startBranch = project.DefaultBranch;
+
+        Assert.That(() => project.Repository.Commit(new()
+        {
+            Branch = "new-branch",
+            StartBranch = startBranch,
+            StartSha = initCommit.Sha,
+            CommitMessage = "First commit in new branch",
+            Actions = new List<CreateCommitAction>
+            {
+                new()
+                {
+                    Action = "update",
+                    Content = "This is in a new branch",
+                    FilePath = "README.md",
+                },
+            },
+        }), Throws.TypeOf<GitLabBadRequestException>()
+                  .With.Message.Contains("GitLab server returned an error (BadRequest): start_branch, start_sha are mutually exclusive."));
+    }
+
+    [Test]
+    public void Test_create_a_new_commit_with_start_branch_fails_if_branch_already_exists()
+    {
+        // Arrange
+        using var server = new GitLabServer();
+        var user = server.Users.AddNew();
+        var project = user.Namespace.Projects.AddNew(project => project.Visibility = VisibilityLevel.Internal);
+        var initCommit = project.Repository.Commit(user, "Initial commit");
+
+        project.Repository.CreateBranch("new-branch", initCommit.Sha);
+
+        var startBranch = project.DefaultBranch;
+        var newBranch = "new-branch";
+
+        // Act & Assert
+        Assert.That(() => project.Repository.Commit(new()
+        {
+            Branch = newBranch,
+            StartBranch = startBranch,
+            CommitMessage = "First commit in new branch",
+            Actions = new List<CreateCommitAction>
+            {
+                new()
+                {
+                    Action = "update",
+                    Content = "This is in a new branch",
+                    FilePath = "README.md",
+                },
+            },
+        }), Throws.TypeOf<GitLabBadRequestException>()
+                  .With.Message.Contains($"A branch called '{newBranch}' already exists."));
+    }
+
+    [Test]
+    public void Test_create_a_new_commit_with_start_sha_fails_if_branch_already_exists()
+    {
+        // Arrange
+        using var server = new GitLabServer();
+        var user = server.Users.AddNew();
+        var project = user.Namespace.Projects.AddNew(project => project.Visibility = VisibilityLevel.Internal);
+        var initCommit = project.Repository.Commit(user, "Initial commit");
+
+        project.Repository.CreateBranch("new-branch", initCommit.Sha);
+
+        var startBranch = project.DefaultBranch;
+        var newBranch = "new-branch";
+
+        // Act & Assert
+        Assert.That(() => project.Repository.Commit(new()
+        {
+            Branch = newBranch,
+            StartSha = initCommit.Sha,
+            CommitMessage = "First commit in new branch",
+            Actions = new List<CreateCommitAction>
+            {
+                new()
+                {
+                    Action = "create",
+                    Content = "This is in a new branch",
+                    FilePath = "README.md",
+                },
+            },
+        }), Throws.TypeOf<GitLabBadRequestException>()
+                  .With.Message.Contains($"A branch called '{newBranch}' already exists."));
+    }
+
+    [Test]
+    public void Test_create_a_new_commit_on_new_branch_with_start_branch()
+    {
+        // Arrange
+        using var server = new GitLabServer();
+        var user = server.Users.AddNew();
+        var project = user.Namespace.Projects.AddNew(project => project.Visibility = VisibilityLevel.Internal);
+        var initCommit = project.Repository.Commit(user, "Initial commit");
+
+        var startBranch = project.DefaultBranch;
+        var newBranch = "new-branch";
+
+        // Act & Assert
+        var commitMessage = "First commit in new branch";
+        var newCommit = project.Repository.Commit(new()
+        {
+            Branch = newBranch,
+            StartBranch = startBranch,
+            CommitMessage = commitMessage,
+            Actions = new List<CreateCommitAction>
+            {
+                new()
+                {
+                    Action = "create",
+                    Content = "This is in a new branch",
+                    FilePath = "README.md",
+                },
+            },
+        });
+        newCommit.Message.Trim().Should().Be(commitMessage);
+    }
+
+    [Test]
+    public void Test_create_a_new_commit_on_new_branch_with_start_sha()
+    {
+        // Arrange
+        using var server = new GitLabServer();
+        var user = server.Users.AddNew();
+        var project = user.Namespace.Projects.AddNew(project => project.Visibility = VisibilityLevel.Internal);
+        var initCommit = project.Repository.Commit(user, "Initial commit");
+
+        var newBranch = "new-branch";
+
+        // Act & Assert
+        var commitMessage = "First commit in new branch";
+        var newCommit = project.Repository.Commit(new()
+        {
+            Branch = newBranch,
+            StartSha = initCommit.Sha,
+            CommitMessage = commitMessage,
+            Actions = new List<CreateCommitAction>
+            {
+                new()
+                {
+                    Action = "create",
+                    Content = "This is in a new branch",
+                    FilePath = "README.md",
+                },
+            },
+        });
+        newCommit.Message.Trim().Should().Be(commitMessage);
+    }
+
+    [Test]
+    public void Test_create_a_new_commit_on_nonexistent_branch()
+    {
+        // Arrange
+        using var server = new GitLabServer();
+        var user = server.Users.AddNew();
+        var project = user.Namespace.Projects.AddNew(project => project.Visibility = VisibilityLevel.Internal);
+        var initCommit = project.Repository.Commit(user, "Initial commit");
+
+        // Act & Assert
+        var commitMessage = "First commit in non existing branch";
+        Assert.That(() => project.Repository.Commit(new()
+        {
+            Branch = "new-branch",
+            CommitMessage = commitMessage,
+            Actions = new List<CreateCommitAction>
+            {
+                new()
+                {
+                    Action = "create",
+                    Content = "This is in a new branch",
+                    FilePath = "README.md",
+                },
+            },
+        }), Throws.TypeOf<GitLabBadRequestException>()
+                  .With.Message.Contains("You can only create or edit files when you are on a branch."));
+    }
+
+    [Test]
+    public void Test_create_a_new_commit_on_existing_branch()
+    {
+        // Arrange
+        using var server = new GitLabServer();
+        var user = server.Users.AddNew();
+        var project = user.Namespace.Projects.AddNew(project => project.Visibility = VisibilityLevel.Internal);
+        var initCommit = project.Repository.Commit(user, "Initial commit");
+
+        // Act & Assert
+        var commitMessage = "First commit in existing branch";
+        var newCommit = project.Repository.Commit(new()
+        {
+            Branch = project.DefaultBranch,
+            CommitMessage = commitMessage,
+            Actions = new List<CreateCommitAction>
+            {
+                new()
+                {
+                    Action = "create",
+                    Content = "This is in an existing branch",
+                    FilePath = "README.md",
+                },
+            },
+        });
+        newCommit.Message.Trim().Should().Be(commitMessage);
+    }
+}

NGitLab.Mock/Repository.cs

@@ -201,26 +201,27 @@ public Commit Commit(User user, string message, string targetBranch, IEnumerable
     public Commit Commit(CommitCreate commitCreate)
     {
         var repo = GetGitRepository();
-        var branchExists = repo.Branches.Any(b => string.Equals(b.FriendlyName, commitCreate.Branch, StringComparison.Ordinal));
+        var hasStartBranch = !string.IsNullOrWhiteSpace(commitCreate.StartBranch);
+        var hasStartSha = !string.IsNullOrWhiteSpace(commitCreate.StartSha);
+        var isCreatingBranch = hasStartBranch || hasStartSha;
 
-        if (branchExists)
+        var branchExistsAlready = repo.Branches.Any(b => string.Equals(b.FriendlyName, commitCreate.Branch, StringComparison.Ordinal));
+
+        if (isCreatingBranch && branchExistsAlready)
         {
             throw new GitLabBadRequestException($"A branch called '{commitCreate.Branch}' already exists.");
         }
 
         var isRepoEmpty = !repo.Commits.Any();
         if (!isRepoEmpty)
         {
-            var hasStartBranch = !string.IsNullOrWhiteSpace(commitCreate.StartBranch);
-            var hasStartSha = !string.IsNullOrWhiteSpace(commitCreate.StartSha);
-
             var @ref = (hasStartBranch, hasStartSha) switch
             {
                 (true, true) => throw new GitLabBadRequestException(
                     "GitLab server returned an error (BadRequest): start_branch, start_sha are mutually exclusive."),
                 (true, _) => commitCreate.StartBranch,
                 (_, true) => commitCreate.StartSha,
-                _ => throw new GitLabBadRequestException(
+                _ => branchExistsAlready ? commitCreate.Branch : throw new GitLabBadRequestException(
                     "GitLab server returned an error (BadRequest): You can only create or edit files when you are on a branch.")
             };
 
@@ -229,7 +230,7 @@ public Commit Commit(CommitCreate commitCreate)
 
         var commit = CreateOnNonBareRepo(commitCreate);
         var branchStillMissing = !repo.Branches.Any(b => string.Equals(b.FriendlyName, commitCreate.Branch, StringComparison.Ordinal));
-        if (!isRepoEmpty || branchStillMissing)
+        if ((isCreatingBranch || isRepoEmpty) && (!isRepoEmpty || branchStillMissing))
         {
             repo.Branches.Add(commitCreate.Branch, commit.Sha);
         }

NGitLab.Tests/CommitsTests.cs

@@ -193,7 +193,7 @@ public async Task Test_create_commit_in_new_branch_fails_if_both_start_branch_an
 
     [Test]
     [NGitLabRetry]
-    public async Task Test_create_commit_in_so_called_new_branch_fails_if_branch_exists()
+    public async Task Test_create_a_new_commit_with_start_branch_fails_if_branch_already_exists()
     {
         // Arrange
         using var context = await GitLabTestContext.CreateAsync();
@@ -227,7 +227,44 @@ public async Task Test_create_commit_in_so_called_new_branch_fails_if_branch_exi
     }
 
     [Test]
-    public async Task Test_create_commit_when_neither_start_branch_nor_start_sha_specified()
+    [NGitLabRetry]
+    public async Task Test_create_a_new_commit_with_start_sha_fails_if_branch_already_exists()
+    {
+        // Arrange
+        using var context = await GitLabTestContext.CreateAsync();
+        var project = context.CreateProject(initializeWithCommits: true);
+
+        var repoClient = context.Client.GetRepository(project.Id);
+        var commitClient = context.Client.GetCommits(project.Id);
+        var startCommit = context.Client.GetCommits(project.Id).GetCommit(project.DefaultBranch);
+
+        var startBranch = project.DefaultBranch;
+        var startSha = startCommit.Id;
+
+        repoClient.Branches.Create(new BranchCreate { Name = "new-branch", Ref = startBranch });
+
+        // Act/Assert
+        Assert.That(() => commitClient.Create(new CommitCreate
+        {
+            Branch = "new-branch",
+            StartSha = startSha.ToString().ToLowerInvariant(),
+            CommitMessage = "First commit in new branch",
+            Actions = new List<CreateCommitAction>
+            {
+                new()
+                {
+                    Action = "update",
+                    Content = "This is in a new branch",
+                    FilePath = "README.md",
+                },
+            },
+        }), Throws.TypeOf<GitLabException>()
+                  .With.Property(nameof(GitLabException.StatusCode)).EqualTo(HttpStatusCode.BadRequest)
+                  .With.Message.Contains("A branch called 'new-branch' already exists."));
+    }
+
+    [Test]
+    public async Task Test_create_commit_on_nonexistent_branch_fails_when_neither_start_branch_nor_start_sha_specified()
     {
         // Arrange
         using var context = await GitLabTestContext.CreateAsync();