.github/workflows/add_collaborators.yml

# Author: Rishab 
name: Add Collaborators v1.1

on: 
  push:
    branches:
      - master
      - main
      - dev

jobs:
  add-collaborators:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout Repo
        uses: actions/checkout@v2
      - name: Add Collaborators
        uses: actions/github-script@v4.0.2
        with:
          github-token: ${{secrets.ADMIN_GITHUB_TOKEN}}
          script: |
            const fs = require('fs');
            const readline = require('readline');
            const readInterface = readline.createInterface({
              input: fs.createReadStream('./COLLABORATORS'),
              output: process.stdout,
              console: false
            });
            readInterface.on('line', async function(line) {
              try {
                await github.repos.checkCollaborator({
                            owner: context.repo.owner,
                            repo: context.repo.repo,
                            username: line,
                            });
              } catch(err) {
                console.log(err)
                if(err.toString() === "HttpError: Not Found"){
                  await github.repos.addCollaborator({
                            owner: context.repo.owner,
                            repo: context.repo.repo,
                            username: line,
                            permission: 'push'
                            });
                } else { 
                  core.setFailed(err.toString())
                }

              }
            });