automerge-action

GitHub action to automatically merge pull requests when they are ready.

This action will behave differently based on the labels assigned to a pull request:

• automerge means that changes from the base branch will automatically be merged into the pull request, but only when "Require branches to be up to date before merging" is enabled in the branch protection rules. When the PR is ready, it will automatically be merged.
• autorebase means that when changes happen in the base branch, the pull request will be rebased onto the base branch. When the PR is ready, it will automatically be merged into the base branch.
• pull requests without one of these labels will be ignored

These labels are configurable, see Configuration.

A pull request is considered ready when:

1. the required number of review approvals has been given (if enabled in the branch protection rules) and
2. the required checks have passed (if enabled in the branch protection rules) and
3. the pull request is up to date (if enabled in the branch protection rules)

After the pull request has been merged successfully, the branch will be deleted (unless there exist branch protection rules preventing this branch from being deleted).

Usage

Add this to your .github/main.workflow file:

workflow "automerge pull requests on updates" {
  on = "pull_request"
  resolves = ["automerge"]
}

workflow "automerge pull requests on reviews" {
  on = "pull_request_review"
  resolves = ["automerge"]
}

workflow "automerge pull requests on status updates" {
  on = "status"
  resolves = ["automerge"]
}

action "automerge" {
  uses = "pascalgn/automerge-action@ef030fabb510b9a5a3bc2e3a0123638e11e72541"
  secrets = ["GITHUB_TOKEN"]
}

Configuration

The following environment variables are supported:

• LABELS: A comma-separated list of labels that will be checked. These labels need to be present for a pull request to be merged. Labels prefixed with an exclamation mark (!) will block a pull request from being merged, when present.

  For example, when !wip,!work in progress,documentation-updated is given, any pull requests with the labels wip or work in progress and any pull requests without the label documentation-updated will not be merged. Blocking labels take precedence, so if a pull request has both labels wip and documentation-updated, it will not be merged.

• AUTOMERGE: The label that indicates that the pull request will be merged using the configured merge method (see MERGE_METHOD). When the environment variable is not set, the default label automerge will be used.

• AUTOREBASE: The label that indicates that the pull request will be rebased onto the base branch whenever this pull request is updated. When the pull request is ready, it will be merged using the configured merge method (see MERGE_METHOD). When the environment variable is not set, the default label autorebase will be used.

• MERGE_METHOD: Specify which method to use when merging the pull request into the base branch. Possible values are merge (create a merge commit), rebase (rebase all commits of the branch onto the base branch) or squash (squash all commits into a single commit). The default option is merge.

• TOKEN: In some cases it can be useful to run this action as a certain user (by default, it will run as github-actions). This can be useful if you want to use the Restrict who can push to matching branches option in the branch protection rules, for example.

  To use this setting, you need to create a personal access token for the user (make sure to check public_repo when it's a public repository or repo when it's a private repository). All API requests (merge/rebase) will then be executed as the specified user. The token should be kept secret, so make sure to add it as secret, not as environment variable, in the GitHub workflow file.

You can configure the environment variables in the workflow file like this:

action "automerge" {
  uses = ...
  secrets = ["GITHUB_TOKEN"]
  env = {
    LABELS = "!wip,!work in progress,documentation-updated"
    AUTOMERGE = "ready-to-merge"
    AUTOREBASE = "ready-to-rebase-and-merge"
    MERGE_METHOD = "squash"
  }
}

License

MIT