Function createMultiFileCommitWithCoAuthors

src/utils/github.ts:340–427

(
  token: string,
  owner: string,
  repo: string,
  branch: string,
  files: { path: string; content: string }[],
  commitMessage: string,
  coAuthors: { name: string; email: string }[]
)

 * This is the core function for Pair Extraordinaire badge.
 */
export async function createMultiFileCommitWithCoAuthors(
  token: string,
  owner: string,
  repo: string,
  branch: string,
  files: { path: string; content: string }[],
  commitMessage: string,
  coAuthors: { name: string; email: string }[]
) {
  if (files.length === 0) throw new Error('No files to commit.');

  const base = `/repos/${owner}/${repo}`;
  const jsonHeaders = { 'Content-Type': 'application/json' };

  // Build commit message with Co-authored-by trailers
  let fullMessage = commitMessage;
  if (coAuthors.length > 0) {
    fullMessage += '\n\n';
    fullMessage += coAuthors
      .map(ca => `Co-authored-by: ${ca.name} <${ca.email}>`)
      .join('\n');
  }

  // Step 1: Get the current commit SHA that the branch points to
  const refRes = await ghFetch(`${base}/git/ref/heads/${encodeURIComponent(branch)}`, token);
  if (!refRes.ok) await handleGitError(refRes, 'Failed to get branch ref');
  const refData = await refRes.json();
  const latestCommitSHA: string = refData.object.sha;

  // Step 2: Get the tree SHA of that commit
  const commitRes = await ghFetch(`${base}/git/commits/${latestCommitSHA}`, token);
  if (!commitRes.ok) await handleGitError(commitRes, 'Failed to get commit');
  const commitData = await commitRes.json();
  const baseTreeSHA: string = commitData.tree.sha;

  // Step 3: Create blobs for EACH file
  const treeEntries: { path: string; mode: string; type: string; sha: string }[] = [];
  for (const file of files) {
    const base64Content = utf8ToBase64(file.content);
    const blobRes = await ghFetch(`${base}/git/blobs`, token, {
      method: 'POST',
      body: JSON.stringify({ content: base64Content, encoding: 'base64' }),
      headers: jsonHeaders,
    });
    if (!blobRes.ok) await handleGitError(blobRes, `Failed to create blob for ${file.path}`);
    const blobData = await blobRes.json();
    treeEntries.push({
      path: file.path,
      mode: '100644',
      type: 'blob',
      sha: blobData.sha,
    });
  }

  // Step 4: Create a new tree with ALL file entries
  const treeRes = await ghFetch(`${base}/git/trees`, token, {
    method: 'POST',
    body: JSON.stringify({ base_tree: baseTreeSHA, tree: treeEntries }),