Merge pull request modelcontextprotocol#166 from mikegehard/feature/git-checkout-command

Allow to check out branches

Author: dsp-ant

src/git/README.md

@@ -67,6 +67,12 @@ Please note that mcp-server-git is currently in early development. The functiona
      - `branch_name` (string): Name of the new branch
      - `start_point` (string, optional): Starting point for the new branch
    - Returns: Confirmation of branch creation
+8. `git_checkout`
+   - Switches branches
+   - Inputs:
+     - `repo_path` (string): Path to Git repository
+     - `branch_name` (string): Name of branch to checkout
+   - Returns: Confirmation of branch switch
 
 ## Installation
 

src/git/pyproject.toml

@@ -30,4 +30,10 @@ requires = ["hatchling"]
 build-backend = "hatchling.build"
 
 [tool.uv]
-dev-dependencies = ["pyright>=1.1.389", "ruff>=0.7.3"]
+dev-dependencies = ["pyright>=1.1.389", "ruff>=0.7.3", "pytest>=8.0.0"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+python_files = "test_*.py"
+python_classes = "Test*"
+python_functions = "test_*"

src/git/src/mcp_server_git/server.py

@@ -48,6 +48,10 @@ class GitCreateBranch(BaseModel):
     branch_name: str
     base_branch: str | None = None
 
+class GitCheckout(BaseModel):
+    repo_path: str
+    branch_name: str
+
 class GitTools(str, Enum):
     STATUS = "git_status"
     DIFF_UNSTAGED = "git_diff_unstaged"
@@ -58,6 +62,7 @@ class GitTools(str, Enum):
     RESET = "git_reset"
     LOG = "git_log"
     CREATE_BRANCH = "git_create_branch"
+    CHECKOUT = "git_checkout"
 
 def git_status(repo: git.Repo) -> str:
     return repo.git.status()
@@ -104,6 +109,10 @@ def git_create_branch(repo: git.Repo, branch_name: str, base_branch: str | None
     repo.create_head(branch_name, base)
     return f"Created branch '{branch_name}' from '{base.name}'"
 
+def git_checkout(repo: git.Repo, branch_name: str) -> str:
+    repo.git.checkout(branch_name)
+    return f"Switched to branch '{branch_name}'"
+
 async def serve(repository: Path | None) -> None:
     logger = logging.getLogger(__name__)
 
@@ -165,6 +174,11 @@ async def list_tools() -> list[Tool]:
                 description="Creates a new branch from an optional base branch",
                 inputSchema=GitCreateBranch.schema(),
             ),
+            Tool(
+                name=GitTools.CHECKOUT,
+                description="Switches branches",
+                inputSchema=GitCheckout.schema(),
+            ),
         ]
 
     async def list_repos() -> Sequence[str]:
@@ -269,6 +283,13 @@ async def call_tool(name: str, arguments: dict) -> list[TextContent]:
                     text=result
                 )]
 
+            case GitTools.CHECKOUT:
+                result = git_checkout(repo, arguments["branch_name"])
+                return [TextContent(
+                    type="text",
+                    text=result
+                )]
+
             case _:
                 raise ValueError(f"Unknown tool: {name}")
 

src/git/tests/test_server.py

@@ -0,0 +1,30 @@
+import pytest
+from pathlib import Path
+import git
+from mcp_server_git.server import git_checkout
+import shutil
+
+@pytest.fixture
+def test_repository(tmp_path: Path):
+    repo_path = tmp_path / "temp_test_repo"
+    test_repo = git.Repo.init(repo_path)
+
+    Path(repo_path / "test.txt").write_text("test")
+    test_repo.index.add(["test.txt"])
+    test_repo.index.commit("initial commit")
+
+    yield test_repo
+
+    shutil.rmtree(repo_path)
+
+def test_git_checkout_existing_branch(test_repository):
+    test_repository.git.branch("test-branch")
+    result = git_checkout(test_repository, "test-branch")
+
+    assert "Switched to branch 'test-branch'" in result
+    assert test_repository.active_branch.name == "test-branch"
+
+def test_git_checkout_nonexistent_branch(test_repository):
+
+    with pytest.raises(git.GitCommandError):
+        git_checkout(test_repository, "nonexistent-branch")