Auto fix conflicts in certain files

[spalger]

In the Kibana repo specifically there are a handful of files which regularly experience conflicts that could be fixed automatically if we knew that conflicts were limited to a specific set of files. I wonder if we could define a module which would be loaded to inspect the conflicting files to decide if the conflicts could be fixed automatically?

Something like this perhaps?

require('backport').run({
  async autoFixConflicts(files, directory, log) {
	const candidates = [
      'yarn.lock',
      'packages/kbn-pm/dist/index.js'
    ]

	const noCandidates = files.every(f => !candidates.includes(f))
	if (noCandidates) {
      log.info('conflicts are not in auto fixable files')
      return false;
    }

    const nonCandidates = files.filter(f => !candidates.includes(f))
	if (nonCandidates.length) {
      log.info('unable to auto fix conflicts because of changes in', nonCandidates.join(', '))
      return false;
    }

    await execa('git', ['checkout', '--', ...files], { cwd: directory })

    log.info('bootstrapping backport repo')
    await execa('yarn', ['kbn', 'bootstrap'], { cwd: directory })

    if (files.includes('packages/kbn-pm/dist/index.js')) {
      log.info('auto fixing kbn/pm dist')
      await execa('yarn', ['kbn', 'run', 'build', '-i', '@kbn/pm'], { cwd: directory })
    }

    return true;
  }
})

[sorenlouv]

We could definitely do something like that. I've been considering converting the .backportrc.json config to a javascript file (.backportrc.js) to support dynamic stuff like this.

{
  upstream: 'elastic/kibana',
  branches: ['7.x', '7.8', '7.7', '...'],
  onConflict: async (files, directory, log) { // ... }
}

But it would probably be easier to start with the approach you suggest. Then I think all options should be configurable that way:

require("backport").run({
  upstream: 'elastic/kibana',
  branches: ['7.x', '7.8', '7.7', '...'],
  onConflict: async (files, directory, log) { // ... }
})