[ Github Actions ] Automatically assign assignee to dependabot PRs

!README.md

What is this?

Github Actions workflow dedicated to automatically assign random assignee to PRs created by dependabot.

Context

Dependabot automatically creates PRs based on the updates of packages and libraries that project is depended on. When PRs are created, team members should check if upgrading the version will break the project or not. In case of breaking changes, member should refactor the project accordingly. Although PRs are created, often these PRs are left unchecked as team members become busy. In accordance to the situation, assigning members randomly would prevent PRs being unchecked.

How it works

on: pull_request_target runs on creation of pull request

if: ${{ github.actor == 'dependabot[bot]' }} allow actions to be run only PR is created by dependabot.

uses: actions/github-script@v6 action that allows running javascript inside the workflow

Reference

https://dev.classmethod.jp/articles/github-dependabot-auto-merge/ [JA]

https://zenn.dev/cumet04/articles/actions-firstparty-random-assign [JA]

dependabot.yaml

version: 2
enable-beta-ecosystems: true
updates:
  - package-ecosystem: "pub" # change to package ecosystem you are using.(ex. npm)
    directory: "/"
    schedule:
      interval: weekly

dependabot_auto_assign.yaml

name: Dependabot auto-assign
on: pull_request_target

permissions:
  pull-requests: write
  contents: write
  
jobs:
  dependabot:
    runs-on: ubuntu-latest
    if: ${{ github.actor == 'dependabot[bot]' }}
    timeout-minutes: 5
    steps:
      - uses: actions/github-script@v6
        with:
          script: |
            const names = [
              // MEMO: change members accordingly
              'foo-',
              'bar-',
              'baz-',
            ]
            const index = Math.floor(Math.random() * names.length)
            const assignee = names[index]

            github.rest.issues.addAssignees({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              assignees: [assignee]
            })
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        if: ${{ toJSON(github.event.pull_request.assignees) == '[]' }}