Add branches operations module

src/github/operations/branches.ts

@@ -0,0 +1,112 @@
+import { z } from "zod";
+import { githubRequest } from "../common/utils";
+import { GitHubReferenceSchema } from "../common/types";
+
+// Schema definitions
+export const CreateBranchOptionsSchema = z.object({
+  ref: z.string(),
+  sha: z.string(),
+});
+
+export const CreateBranchSchema = z.object({
+  owner: z.string().describe("Repository owner (username or organization)"),
+  repo: z.string().describe("Repository name"),
+  branch: z.string().describe("Name for the new branch"),
+  from_branch: z.string().optional().describe("Optional: source branch to create from (defaults to the repository's default branch)"),
+});
+
+// Type exports
+export type CreateBranchOptions = z.infer<typeof CreateBranchOptionsSchema>;
+
+// Function implementations
+export async function getDefaultBranchSHA(owner: string, repo: string): Promise<string> {
+  try {
+    const response = await githubRequest(
+      `https://api.github.com/repos/${owner}/${repo}/git/refs/heads/main`
+    );
+    const data = GitHubReferenceSchema.parse(response);
+    return data.object.sha;
+  } catch (error) {
+    const masterResponse = await githubRequest(
+      `https://api.github.com/repos/${owner}/${repo}/git/refs/heads/master`
+    );
+    if (!masterResponse) {
+      throw new Error("Could not find default branch (tried 'main' and 'master')");
+    }
+    const data = GitHubReferenceSchema.parse(masterResponse);
+    return data.object.sha;
+  }
+}
+
+export async function createBranch(
+  owner: string,
+  repo: string,
+  options: CreateBranchOptions
+): Promise<z.infer<typeof GitHubReferenceSchema>> {
+  const fullRef = `refs/heads/${options.ref}`;
+
+  const response = await githubRequest(
+    `https://api.github.com/repos/${owner}/${repo}/git/refs`,
+    {
+      method: "POST",
+      body: {
+        ref: fullRef,
+        sha: options.sha,
+      },
+    }
+  );
+
+  return GitHubReferenceSchema.parse(response);
+}
+
+export async function getBranchSHA(
+  owner: string,
+  repo: string,
+  branch: string
+): Promise<string> {
+  const response = await githubRequest(
+    `https://api.github.com/repos/${owner}/${repo}/git/refs/heads/${branch}`
+  );
+
+  const data = GitHubReferenceSchema.parse(response);
+  return data.object.sha;
+}
+
+export async function createBranchFromRef(
+  owner: string,
+  repo: string,
+  newBranch: string,
+  fromBranch?: string
+): Promise<z.infer<typeof GitHubReferenceSchema>> {
+  let sha: string;
+  if (fromBranch) {
+    sha = await getBranchSHA(owner, repo, fromBranch);
+  } else {
+    sha = await getDefaultBranchSHA(owner, repo);
+  }
+
+  return createBranch(owner, repo, {
+    ref: newBranch,
+    sha,
+  });
+}
+
+export async function updateBranch(
+  owner: string,
+  repo: string,
+  branch: string,
+  sha: string
+): Promise<z.infer<typeof GitHubReferenceSchema>> {
+  const response = await githubRequest(
+    `https://api.github.com/repos/${owner}/${repo}/git/refs/heads/${branch}`,
+    {
+      method: "PATCH",
+      body: {
+        sha,
+        force: true,
+      },
+    }
+  );
+
+  return GitHubReferenceSchema.parse(response);
+}