feat: add branch comparison functionality and update related schemas

index.ts

@@ -53,7 +53,7 @@ import {
   CreateMergeRequestSchema,
   ForkRepositorySchema,
   CreateBranchSchema,
-  GitLabMergeRequestDiffSchema,
+  GitLabDiffSchema,
   GetMergeRequestSchema,
   GetMergeRequestDiffsSchema,
   UpdateMergeRequestSchema,
@@ -126,6 +126,9 @@ import {
   GetRepositoryTreeSchema,
   type GitLabTreeItem,
   type GetRepositoryTreeOptions,
+  GitLabCompareResult,
+  GitLabCompareResultSchema,
+  GetBranchDiffsSchema,
 } from "./schemas.js";
 
 /**
@@ -261,6 +264,12 @@ const allTools = [
       "Get the changes/diffs of a merge request (Either mergeRequestIid or branchName must be provided)",
     inputSchema: zodToJsonSchema(GetMergeRequestDiffsSchema),
   },
+  {
+    name: "get_branch_diffs",
+    description:
+      "Get the changes/diffs between two branches or commits in a GitLab project",
+    inputSchema: zodToJsonSchema(GetBranchDiffsSchema),
+  },
   {
     name: "update_merge_request",
     description:
@@ -436,6 +445,7 @@ const readOnlyTools = [
   "get_file_contents",
   "get_merge_request",
   "get_merge_request_diffs",
+  "get_branch_diffs",
   "mr_discussions",
   "list_issues",
   "get_issue",
@@ -1552,7 +1562,50 @@ async function getMergeRequestDiffs(
 
   await handleGitLabError(response);
   const data = (await response.json()) as { changes: unknown };
-  return z.array(GitLabMergeRequestDiffSchema).parse(data.changes);
+  return z.array(GitLabDiffSchema).parse(data.changes);
+}
+
+/**
+ * Get branch comparison diffs
+ *
+ * @param {string} projectId - The ID or URL-encoded path of the project
+ * @param {string} from - The branch name or commit SHA to compare from
+ * @param {string} to - The branch name or commit SHA to compare to
+ * @param {boolean} [straight] - Comparison method: false for '...' (default), true for '--'
+ * @returns {Promise<GitLabCompareResult>} Branch comparison results
+ */
+async function getBranchDiffs(
+  projectId: string,
+  from: string,
+  to: string,
+  straight?: boolean
+): Promise<GitLabCompareResult> {
+  projectId = decodeURIComponent(projectId); // Decode project ID
+  
+  const url = new URL(
+    `${GITLAB_API_URL}/projects/${encodeURIComponent(projectId)}/repository/compare`
+  );
+  
+  url.searchParams.append("from", from);
+  url.searchParams.append("to", to);
+  
+  if (straight !== undefined) {
+    url.searchParams.append("straight", straight.toString());
+  }
+
+  const response = await fetch(url.toString(), {
+    ...DEFAULT_FETCH_CONFIG,
+  });
+
+  if (!response.ok) {
+    const errorBody = await response.text();
+    throw new Error(
+      `GitLab API error: ${response.status} ${response.statusText}\n${errorBody}`
+    );
+  }
+
+  const data = await response.json();
+  return GitLabCompareResultSchema.parse(data);
 }
 
 /**
@@ -2414,6 +2467,19 @@ server.setRequestHandler(CallToolRequestSchema, async (request) => {
         };
       }
 
+      case "get_branch_diffs": {
+        const args = GetBranchDiffsSchema.parse(request.params.arguments);
+        const diffs = await getBranchDiffs(
+          args.project_id,
+          args.from,
+          args.to,
+          args.straight
+        );
+        return {
+          content: [{ type: "text", text: JSON.stringify(diffs, null, 2) }],
+        };
+      }
+
       case "search_repositories": {
         const args = SearchRepositoriesSchema.parse(request.params.arguments);
         const results = await searchProjects(

schemas.ts

@@ -271,9 +271,15 @@ export const CreateMergeRequestOptionsSchema = z.object({
   draft: z.boolean().optional(),
 });
 
-export const CreateBranchOptionsSchema = z.object({
-  name: z.string(), // Changed from ref to match GitLab API
-  ref: z.string(), // The source branch/commit for the new branch
+export const GitLabDiffSchema = z.object({
+  old_path: z.string(),
+  new_path: z.string(),
+  a_mode: z.string(),
+  b_mode: z.string(),
+  diff: z.string(),
+  new_file: z.boolean(),
+  renamed_file: z.boolean(),
+  deleted_file: z.boolean(),
 });
 
 // Response schemas for operations
@@ -291,6 +297,27 @@ export const GitLabSearchResponseSchema = z.object({
   items: z.array(GitLabRepositorySchema),
 });
 
+// create branch schemas
+export const CreateBranchOptionsSchema = z.object({
+  name: z.string(), // Changed from ref to match GitLab API
+  ref: z.string(), // The source branch/commit for the new branch
+});
+
+export const GitLabCompareResultSchema = z.object({
+  commit: z.object({
+    id: z.string().optional(),
+    short_id: z.string().optional(),
+    title: z.string().optional(),
+    author_name: z.string().optional(),
+    author_email: z.string().optional(),
+    created_at: z.string().optional(),
+  }).optional(),
+  commits: z.array(GitLabCommitSchema),
+  diffs: z.array(GitLabDiffSchema),
+  compare_timeout: z.boolean().optional(),
+  compare_same_ref: z.boolean().optional(),
+});
+
 // Issue related schemas
 export const GitLabLabelSchema = z.object({
   id: z.number(),
@@ -596,20 +623,16 @@ export const ForkRepositorySchema = ProjectParamsSchema.extend({
   namespace: z.string().optional().describe("Namespace to fork to (full path)"),
 });
 
+// Branch related schemas
 export const CreateBranchSchema = ProjectParamsSchema.extend({
   branch: z.string().describe("Name for the new branch"),
   ref: z.string().optional().describe("Source branch/commit for new branch"),
 });
 
-export const GitLabMergeRequestDiffSchema = z.object({
-  old_path: z.string(),
-  new_path: z.string(),
-  a_mode: z.string(),
-  b_mode: z.string(),
-  diff: z.string(),
-  new_file: z.boolean(),
-  renamed_file: z.boolean(),
-  deleted_file: z.boolean(),
+export const GetBranchDiffsSchema = ProjectParamsSchema.extend({
+  from: z.string().describe("The base branch or commit SHA to compare from"),
+  to: z.string().describe("The target branch or commit SHA to compare to"),
+  straight: z.boolean().optional().describe("Comparison method: false for '...' (default), true for '--'"),
 });
 
 export const GetMergeRequestSchema = ProjectParamsSchema.extend({
@@ -1082,6 +1105,7 @@ export type GitLabDirectoryContent = z.infer<
 export type GitLabContent = z.infer<typeof GitLabContentSchema>;
 export type FileOperation = z.infer<typeof FileOperationSchema>;
 export type GitLabTree = z.infer<typeof GitLabTreeSchema>;
+export type GitLabCompareResult = z.infer<typeof GitLabCompareResultSchema>;
 export type GitLabCommit = z.infer<typeof GitLabCommitSchema>;
 export type GitLabReference = z.infer<typeof GitLabReferenceSchema>;
 export type CreateRepositoryOptions = z.infer<
@@ -1097,7 +1121,7 @@ export type GitLabCreateUpdateFileResponse = z.infer<
 >;
 export type GitLabSearchResponse = z.infer<typeof GitLabSearchResponseSchema>;
 export type GitLabMergeRequestDiff = z.infer<
-  typeof GitLabMergeRequestDiffSchema
+  typeof GitLabDiffSchema
 >;
 export type CreateNoteOptions = z.infer<typeof CreateNoteSchema>;
 export type GitLabIssueLink = z.infer<typeof GitLabIssueLinkSchema>;