combine-prs ➡️📦⬅️

GitHub Action to combine multiple PRs into a single one

About 💡

GitHub uses this Action to combine multiple dependabot PRs into a single one. Rather than having to deploy each PR individually, we can run this Action on a cron or workflow_dispatch to combine all the PRs into a single one to make dependency management just a little bit easier.

This Action is customizable so you can use it for your own purposes and it doesn't have to be specific to dependabot PRs.

Notice 📢

[!NOTE] A notice around the Dependabot Grouped Version Updates feature

As mentioned above is this README, a core reason why this Action exists is to "combine multiple Dependabot PRs into one". Work for this Action was completed before the GitHub Blog Post was published and the Dependabot Grouped Version Updates feature was released. While it may seem like this Action is no longer needed due to this feature, there are actually still quite a few use cases for this Action. The first one that is front of mind is that the PRs which Dependabot opens are grouped by package manager. This means that if you have a project that uses multiple package managers, you'll still end up with multiple PRs. This Action can be used to combine those PRs into a single one. You may also want to combine pull requests that are not related to Dependabot in anyway, which this Action can also do.

Inputs 📝

Name	Description	Default	Required
github_token	GitHub token to use for authentication within this Action. Provided for you by default!	${{ github.token }}	true
branch_prefix	Prefix for the branch name to use for the combined PR	dependabot	true
combine_branch_name	The branch name to use for the combined PR	combined-prs-branch	false
pr_title	The title of the pull request to create	Combined PRs	true
pr_body_header	The header of the pull request body	# Combined PRs ➡️📦⬅️	true
min_combine_number	The minimum number of PRs that have to match criteria in order to create a combined PR	"2"	true
branch_regex	The regex to match the branches to combine - more control than branch_prefix	""	false
ci_required	Whether or not CI should be passing to combine the PR - can be "true" or "false"	"true"	true
review_required	Whether or not reviews should be passing to combine the PR - can be "true" or "false"	"false"	false
ignore_label	The label to ignore when combining PRs	"nocombine"	true
select_label	The label which marks PRs that should be combined. Leave empty to consider all PRs.	""	false
labels	A comma separated list of labels to add to the combined PR - Example: dependencies,combined-pr,etc	""	false
assignees	A comma separated list of assignees the combined PR is assigned to - Example: octocat	""	false
autoclose	Whether or not to close combined PRs if the combined PR is merged - can be "true" or "false"	"true"	false
update_branch	Whether or not to update the combined branch with the latest changes from the base branch after creating the combined pull request	"true"	false
create_from_scratch	Whether or not to start from a clean base branch when (re)creating the combined PR	"false"	false

Outputs 📤

Name	Description
pr_url	The pull request URL if a PR was created
pr_number	The pull request number if a PR was created

Example 📸

Here is a PR example of this Action:

The Action ran on a cron, looked for all branches that had the dependabot prefix and then combined them into a single PR. Three pull requests were successfully combined and one was left out due to merge conflicts.

This allows us to deploy all the dependency updates at once rather than having to deploy each one individually.

Usage 💻

Here is a brief example of how to use this Action in a workflow:

name: Combine PRs

on:
  schedule:
    - cron: '0 1 * * 3' # Wednesday at 01:00
  workflow_dispatch: # allows you to manually trigger the workflow

# The minimum permissions required to run this Action
permissions:
  contents: write
  pull-requests: write
  checks: read

jobs:
  combine-prs:
    runs-on: ubuntu-latest

    steps:
      - name: combine-prs
        id: combine-prs
        uses: github/combine-prs@vX.X.X # where X.X.X is the latest version
        with:
          labels: combined-pr # Optional: add a label to the combined PR

Permissions

This Action requires the following permissions:

# The minimum permissions required to run this Action
permissions:
  contents: write # to create a new branch and merge other branches together
  pull-requests: write # to create a new PR with the combined changes
  checks: read # to check if CI is passing or not before combining PRs

This Action also requires that GitHub Action's has permissions to create new pull requests. You can read more about this feature here: GitHub Blog Post

To enable this setting, go to Actions > General > Workflow permissions in your repository settings. Check the following box and click save:

Regex Branch Patterns

By default, this Action uses the branch_prefix option set to dependabot to match the branches to combine. However, you can also use the branch_regex option to match branches using a regex pattern. This is useful if you want to match branches that don't have a specific prefix.

branch_regex is a string representing a regex pattern

If branch_regex is set, branch_prefix will be ignored.

CI and Action's Token 🤖

If you need CI to re-run on your newly created "combined" PR, you'll need to use a token that has write access to your repository. This is because the default github.token that is provided to Actions prevents CI from running on new commits to prevent recursive workflows. You can use a personal access token or a GitHub App token to get around this.

- name: combine-prs
  id: combine-prs
  uses: github/combine-prs@vX.X.X # where X.X.X is the latest version
  with:
    github_token: ${{ secrets.PAT }} # where PAT is a GitHub Action's secret containing a personal access token

GitHub App Setup

Alternatively, you can use a GitHub App token. This is the recommended approach as it is more secure than a personal access token and a lot more scalable for large organizations.

Checkout the dedicated documentation here for more information on how to set this up.