rebase hundreds of automated commits into linear history

fixbranches.js

const util = require('util');
const exec = util.promisify(require('child_process').exec);
const ex =  async (cmd) => {
  console.log({cmd});
  return exec(cmd).then(console.log);
}
async function run(branch) {
  try {
      await ex(`git switch ${branch}`);
      await ex(`git rebase master -X ours`);
      await ex(`git switch master`);
      await ex(`git merge ${branch}`);
  }catch (err){
     console.error(err);
     process.exit(1);
  };
};



let branches = `
origin/production-refresh/2021-04-14T07-08-58

...[hundreds of branches]...

  origin/production-refresh/2021-05-31T00-26-04
`;

branches = branches.split('\n').map(s => s.trim()).filter(s => !!s);

(async () => {
  await ex(`git switch master -f`);
  await ex(`git reset --hard`)
  await ex(`git reset origin/master --hard`);
  for (const b of branches) {
    await run(b.replace('origin/', ''));
  }
})()