feat: Add MR/PR detail functionality - get diff and commits

git_mcp/mcp_server.py

@@ -316,6 +316,56 @@ async def list_my_merge_requests(
     )
 
 
+@mcp.tool()
+async def get_merge_request_diff(
+    platform: str, project_id: str, mr_id: str, **options
+) -> Dict[str, Any]:
+    """Get diff/changes for a merge request
+
+    Args:
+        platform: The platform name (e.g., 'gitlab', 'github')
+        project_id: The project identifier
+        mr_id: The merge request/pull request ID
+        **options: Optional parameters:
+            - format: Response format ('json', 'unified') - default: 'json'
+            - include_diff: Include actual diff content (bool) - default: True
+
+    Returns:
+        Dict containing:
+            - mr_id: The merge request ID
+            - total_changes: Summary of additions, deletions, files changed
+            - files: List of changed files with details
+            - diff_format: Format of the response
+            - truncated: Whether response was truncated
+    """
+    return await PlatformService.get_merge_request_diff(
+        platform, project_id, mr_id, **options
+    )
+
+
+@mcp.tool()
+async def get_merge_request_commits(
+    platform: str, project_id: str, mr_id: str, **filters
+) -> Dict[str, Any]:
+    """Get commits for a merge request
+
+    Args:
+        platform: The platform name (e.g., 'gitlab', 'github')
+        project_id: The project identifier
+        mr_id: The merge request/pull request ID
+        **filters: Optional filters for commit selection
+
+    Returns:
+        Dict containing:
+            - mr_id: The merge request ID
+            - total_commits: Number of commits
+            - commits: List of commit details with sha, message, author, dates, etc.
+    """
+    return await PlatformService.get_merge_request_commits(
+        platform, project_id, mr_id, **filters
+    )
+
+
 # Fork operations
 @mcp.tool()
 async def create_fork(platform: str, project_id: str, **kwargs) -> Dict[str, Any]:

git_mcp/platforms/base.py

@@ -236,6 +236,20 @@ async def merge_merge_request(
         """Merge a merge request."""
         pass
 
+    @abstractmethod
+    async def get_merge_request_diff(
+        self, project_id: str, mr_id: str, **options
+    ) -> Dict[str, Any]:
+        """Get diff/changes for a merge request."""
+        pass
+
+    @abstractmethod
+    async def get_merge_request_commits(
+        self, project_id: str, mr_id: str, **filters
+    ) -> Dict[str, Any]:
+        """Get commits for a merge request."""
+        pass
+
     # Repository operations
     @abstractmethod
     async def list_branches(self, project_id: str, **filters) -> List[Dict[str, Any]]:

git_mcp/platforms/github.py

@@ -731,6 +731,123 @@ async def get_fork_parent(self, project_id: str) -> Optional[str]:
                 f"Failed to get fork parent for {project_id}: {e}", self.platform_name
             )
 
+    async def get_merge_request_diff(
+        self, project_id: str, mr_id: str, **options
+    ) -> Dict[str, Any]:
+        """Get diff/changes for a GitHub pull request."""
+        if not self.client:
+            await self.authenticate()
+
+        try:
+            repo = self.client.get_repo(project_id)
+            pr = repo.get_pull(int(mr_id))
+
+            # Get diff format option (default: json)
+            diff_format = options.get("format", "json")
+            include_diff = options.get("include_diff", True)
+
+            # Get files changed in the PR
+            files = list(pr.get_files())
+
+            # Initialize response structure
+            response = {
+                "mr_id": str(mr_id),
+                "total_changes": {
+                    "additions": pr.additions,
+                    "deletions": pr.deletions,
+                    "files_changed": len(files),
+                },
+                "files": [],
+                "diff_format": diff_format,
+                "truncated": False,
+            }
+
+            # Process file changes
+            for file in files:
+                file_info = {
+                    "path": file.filename,
+                    "status": file.status,  # GitHub provides: added, removed, modified, renamed
+                    "additions": file.additions,
+                    "deletions": file.deletions,
+                    "binary": file.filename.endswith(
+                        (".png", ".jpg", ".jpeg", ".gif", ".pdf", ".zip", ".exe")
+                    ),
+                }
+
+                # Include diff content if requested and file is not too large
+                if (
+                    include_diff
+                    and not file_info["binary"]
+                    and hasattr(file, "patch")
+                    and file.patch
+                ):
+                    file_info["diff"] = file.patch
+
+                response["files"].append(file_info)
+
+            return response
+
+        except GithubException as e:
+            if e.status == 404:
+                raise ResourceNotFoundError("pull_request", mr_id, self.platform_name)
+            raise PlatformError(
+                f"Failed to get pull request diff {mr_id}: {e}", self.platform_name
+            )
+
+    async def get_merge_request_commits(
+        self, project_id: str, mr_id: str, **filters
+    ) -> Dict[str, Any]:
+        """Get commits for a GitHub pull request."""
+        if not self.client:
+            await self.authenticate()
+
+        try:
+            repo = self.client.get_repo(project_id)
+            pr = repo.get_pull(int(mr_id))
+
+            # Get commits from the pull request
+            commits = list(pr.get_commits())
+
+            response: Dict[str, Any] = {
+                "mr_id": str(mr_id),
+                "total_commits": len(commits),
+                "commits": [],
+            }
+
+            # Process each commit
+            for commit in commits:
+                commit_info = {
+                    "sha": commit.sha,
+                    "message": commit.commit.message,
+                    "author": commit.commit.author.name if commit.commit.author else "",
+                    "authored_date": commit.commit.author.date.isoformat()
+                    if commit.commit.author and commit.commit.author.date
+                    else "",
+                    "committer": commit.commit.committer.name
+                    if commit.commit.committer
+                    else "",
+                    "committed_date": commit.commit.committer.date.isoformat()
+                    if commit.commit.committer and commit.commit.committer.date
+                    else "",
+                    "url": commit.html_url,
+                }
+
+                # Add stats if available (GitHub provides these)
+                if hasattr(commit, "stats") and commit.stats:
+                    commit_info["additions"] = commit.stats.additions
+                    commit_info["deletions"] = commit.stats.deletions
+
+                response["commits"].append(commit_info)
+
+            return response
+
+        except GithubException as e:
+            if e.status == 404:
+                raise ResourceNotFoundError("pull_request", mr_id, self.platform_name)
+            raise PlatformError(
+                f"Failed to get pull request commits {mr_id}: {e}", self.platform_name
+            )
+
     def parse_branch_reference(self, branch_ref: str) -> Dict[str, Any]:
         """Parse GitHub branch reference into components.
 

git_mcp/platforms/gitlab.py

@@ -628,6 +628,129 @@ async def get_fork_parent(self, project_id: str) -> Optional[str]:
                 f"Failed to get fork parent for {project_id}: {e}", self.platform_name
             )
 
+    async def get_merge_request_diff(
+        self, project_id: str, mr_id: str, **options
+    ) -> Dict[str, Any]:
+        """Get diff/changes for a GitLab merge request."""
+        if not self.client:
+            await self.authenticate()
+
+        try:
+            project = self.client.projects.get(project_id)
+            mr = project.mergerequests.get(mr_id)
+
+            # Get diff format option (default: json)
+            diff_format = options.get("format", "json")
+            include_diff = options.get("include_diff", True)
+
+            # Get changes using GitLab changes API
+            changes = mr.changes()
+
+            # Initialize response structure
+            response = {
+                "mr_id": str(mr_id),
+                "total_changes": {
+                    "additions": 0,
+                    "deletions": 0,
+                    "files_changed": len(changes.get("changes", [])),
+                },
+                "files": [],
+                "diff_format": diff_format,
+                "truncated": False,
+            }
+
+            # Process file changes
+            for change in changes.get("changes", []):
+                file_info = {
+                    "path": change.get("new_path") or change.get("old_path", ""),
+                    "status": self._get_file_status(change),
+                    "additions": 0,  # GitLab doesn't provide line counts in changes
+                    "deletions": 0,
+                    "binary": change.get("diff", "").startswith("Binary files"),
+                }
+
+                # Include diff content if requested
+                if include_diff and not file_info["binary"]:
+                    file_info["diff"] = change.get("diff", "")
+
+                response["files"].append(file_info)
+
+            # Try to get overall stats from MR
+            if hasattr(mr, "changes_count"):
+                response["total_changes"]["files_changed"] = mr.changes_count
+
+            return response
+
+        except GitlabError as e:
+            if e.response_code == 404:
+                raise ResourceNotFoundError("merge_request", mr_id, self.platform_name)
+            raise PlatformError(
+                f"Failed to get merge request diff {mr_id}: {e}", self.platform_name
+            )
+
+    async def get_merge_request_commits(
+        self, project_id: str, mr_id: str, **filters
+    ) -> Dict[str, Any]:
+        """Get commits for a GitLab merge request."""
+        if not self.client:
+            await self.authenticate()
+
+        try:
+            project = self.client.projects.get(project_id)
+            mr = project.mergerequests.get(mr_id)
+
+            # Get commits from the merge request
+            commits = mr.commits()
+
+            response: Dict[str, Any] = {
+                "mr_id": str(mr_id),
+                "total_commits": len(commits),
+                "commits": [],
+            }
+
+            # Process each commit
+            for commit in commits:
+                commit_info = {
+                    "sha": commit.id,
+                    "message": commit.message,
+                    "author": commit.author_name,
+                    "authored_date": commit.authored_date,
+                    "committer": commit.committer_name,
+                    "committed_date": commit.committed_date,
+                    "url": commit.web_url if hasattr(commit, "web_url") else "",
+                }
+
+                # Add stats if available
+                if hasattr(commit, "stats"):
+                    commit_info["additions"] = getattr(commit.stats, "additions", 0)
+                    commit_info["deletions"] = getattr(commit.stats, "deletions", 0)
+
+                response["commits"].append(commit_info)
+
+            return response
+
+        except GitlabError as e:
+            if e.response_code == 404:
+                raise ResourceNotFoundError("merge_request", mr_id, self.platform_name)
+            raise PlatformError(
+                f"Failed to get merge request commits {mr_id}: {e}", self.platform_name
+            )
+
+    def _get_file_status(self, change: Dict) -> str:
+        """Determine file status from GitLab change object."""
+        new_file = change.get("new_file", False)
+        deleted_file = change.get("deleted_file", False)
+        renamed_file = change.get("renamed_file", False)
+
+        if new_file:
+            return "added"
+        elif deleted_file:
+            return "deleted"
+        elif renamed_file:
+            return "renamed"
+        else:
+            return "modified"
+
     def parse_branch_reference(self, branch_ref: str) -> Dict[str, Any]:
         """Parse GitLab branch reference into components.
 

git_mcp/services/platform_service.py

@@ -737,3 +737,33 @@ async def list_forks(
                 "note": "Use GitHub/GitLab web interface to view forks for now",
             }
         ]
+
+    @staticmethod
+    async def get_merge_request_diff(
+        platform_name: str, project_id: str, mr_id: str, **options
+    ) -> Dict[str, Any]:
+        """Get diff/changes for a merge request."""
+        adapter = PlatformService.get_adapter(platform_name)
+        diff_data = await adapter.get_merge_request_diff(project_id, mr_id, **options)
+
+        diff_data.update(
+            {"platform": platform_name, "project_id": project_id, "mr_id": mr_id}
+        )
+
+        return diff_data
+
+    @staticmethod
+    async def get_merge_request_commits(
+        platform_name: str, project_id: str, mr_id: str, **filters
+    ) -> Dict[str, Any]:
+        """Get commits for a merge request."""
+        adapter = PlatformService.get_adapter(platform_name)
+        commits_data = await adapter.get_merge_request_commits(
+            project_id, mr_id, **filters
+        )
+
+        commits_data.update(
+            {"platform": platform_name, "project_id": project_id, "mr_id": mr_id}
+        )
+
+        return commits_data