Restrict branch X to be merged only from one specific branch Y in Github

Question

My repository belongs to an organization I created. I want to prevent mistakes during pull requests. For example, accidentally allowing the master branch to be merged from a branch other than development.

How can I accomplish this?

Answer 1

Here is an example of creating a github actions workflow that only allows merging from the staging branch or a hotfix/ branch.

name: Main Branch Protection

on:
  pull_request:
    branches:
      - main

jobs:
  check-branch:
    runs-on: ubuntu-latest
    steps:
      - name: Check branch
        run: |
          if [[ ${GITHUB_HEAD_REF} != staging ]] && ! [[ ${GITHUB_HEAD_REF} =~ ^hotfix/ ]]; 
          then
            echo "Error: Pull request must come from 'staging' or 'hotfix/' branch"
            exit 1
          fi

Within the branch protection rules of the repository, you can enforce that this workflow succeeds before merging is allowed. (You should also have require pull request before merging selected too.)