Allow setting reviewers when using github_pull_request

I would like to be able to set the reviewers for PRs created through all-repos.

all-repos-sed ... --reviewers mycolleague

I was going to implement this as a custom push module, but currently push modules can only receive Settings and branch_name.

One approach would be to implement push strategies as classes with a hook for adding additional parser arguments. Something like:

class GitHubPullRequest(BasePushStrategy):
    def add_arguments(self, parser: ParserType):
        parser.add_arguments("--reviewers", nargs="*")

   # or "def handle",  to match Django's management commands
    def __call__(self, settings: Settings, branch_name: str, parsed_args: Any) -> None:
        # ...
        resp = github_api.req(
            f"{settings.base_url}/repos/{repo_slug}/pulls",
            data=data,
            headers=headers,
            method="POST",
        )
        url = resp.json["url"]
        html_url = resp.json["html_url"]
        print(f"Pull request created at {html_url}")
        reviewers = parsed_args.reviewers
        if reviewers:
            resp = github_api.req(
                f"{url}/requested_reviewers",
                data=json.dumps({"reviewers": reviewers}).encode(),
                headers=headers,
                method="POST",
            )
            print(f"Requested review from {reviewers}")

The "push" config in all-repos.json would point to these classes instead of modules.

{
  "push": "all_repos.push.GitHubPullRequest"
}

Open questions:

1. Is the above interface a good idea? 1a. If so, is it OK to implement it as a breaking change?
2. Should the “reviewer” functionality be included in all-repos core?

I don’t have a strong feeling on 2. As long as there’s a way to do it, I’m fine keeping it as custom code outside of core to start. Up to you, @asottile

[sloria]

Fair enough–I can see how allowing plugins to define their own arguments could open Pandora’s Box.

it may make more sense to configure these things in the particular plugins (config files, environment variables, etc. come to mind as alternative ways to accomplish this)

Sure, this seems workable. With https://github.com/asottile/all-repos/pull/132 , I’d be able to do something like

# github_pull_request_with_reviewers.py
from all_repos.push.github_pull_request import make_pull_request

def push(...):
    resp = make_pull_request(settings, branch_name)
    reviewers = os.environ.get('GH_REVIEWERS', '').split(',')
    if reviewers:
        url = resp.json['url']
        resp = github_api.req(
            f"{url}/requested_reviewers",
            data=json.dumps({"reviewers": reviewers}).encode(),
            headers=headers,
            method="POST",
        )

[sloria]

thanks!