chore: keep co-authors in spread commit

Author: shortcuts

scripts/ci/codegen/spreadGeneration.ts

@@ -42,9 +42,16 @@ async function spreadGeneration(): Promise<void> {
     throw new Error('Environment variable `GITHUB_TOKEN` does not exist.');
   }
 
-  const lastCommitMessage = await run(`git log -1 --format="%s"`);
-  const name = (await run(`git log -1 --format="%an"`)).trim();
-  const email = (await run(`git log -1 --format="%ae"`)).trim();
+  const lastCommitMessage = await run('git log -1 --format="%s"');
+  const author = (
+    await run('git log -1 --format="Co-authored-by: %an <%ae>"')
+  ).trim();
+  const coAuthors = (
+    await run('git log -1 --format="%(trailers:key=Co-authored-by)"')
+  )
+    .split('\n')
+    .filter(Boolean);
+
   const commitMessage = cleanUpCommitMessage(lastCommitMessage);
   const langs = decideWhereToSpread(lastCommitMessage);
 
@@ -75,7 +82,7 @@ async function spreadGeneration(): Promise<void> {
     await run(`git add .`, { cwd: tempGitDir });
     await gitCommit({
       message: commitMessage,
-      coauthor: { name, email },
+      coauthors: [author, ...coAuthors],
       cwd: tempGitDir,
     });
     await run(`git push`, { cwd: tempGitDir });

scripts/common.ts

@@ -186,30 +186,16 @@ export async function runIfExists(
 
 export async function gitCommit({
   message,
-  coauthor,
+  coauthors = [],
   cwd = ROOT_DIR,
 }: {
   message: string;
-  coauthor?: {
-    name: string;
-    email: string;
-  };
+  coauthors?: string[];
   cwd?: string;
 }): Promise<void> {
-  await execa(
-    'git',
-    [
-      'commit',
-      '-m',
-      message +
-        (coauthor
-          ? `\n\n\nCo-authored-by: ${coauthor.name} <${coauthor.email}>`
-          : ''),
-    ],
-    {
-      cwd,
-    }
-  );
+  await execa('git', ['commit', '-m', message, '\n\n', ...coauthors], {
+    cwd,
+  });
 }
 
 export async function checkForCache(