index.js

const core = require('@actions/core');
const { exec } = require('@actions/exec');
const github = require('@actions/github');
const { Toolkit } = require('actions-toolkit');

const STRATEGIES = [
  '#patch',
  '#minor',
  '#major'
];

Toolkit.run(async tools => {
  {
    try {
      // get context
      const { pusher: { email, name }, head_commit: { message } } = github.context.payload;

      // get input credentials
      const inputUser = core.getInput('user');
      const inputEmail = core.getInput('email');
      const inputBranch = core.getInput('branch');
      const unrelated = core.getInput('unrelated');

      const userName = inputUser || name;
      const userEmail = inputEmail || email;

      const defaultStrategy = STRATEGIES.filter(strat => message.includes(strat))[0] || STRATEGIES[0];
      const strategy = defaultStrategy.replace('#', '');
      const commitMessage = message.replace(defaultStrategy, '');

      tools.log(`Latest commit message: ${commitMessage}`);
      tools.log(`Running with ${userName} ${userEmail} and bumping strategy ${strategy}`);
      tools.log(`Branch is ${inputBranch}`);


      // git login and pull
      const pullArgs = ['pull', 'origin', inputBranch, '--tags'];
      if (unrelated) {
        pullArgs.push('--allow-unrelated-histories');
      }

      await exec('git', ['config', '--local', 'user.name', userName]);
      await exec('git', ['config', '--local', 'user.email', userEmail]);
      await exec('git', pullArgs);

      // version by strategy
      
      await exec('npm', ['version', strategy, '--no-commit-hooks', '-m', `${commitMessage} %s`]);

      const version = tools.getPackageJSON().version;
      core.info(`version is ${version}`);
      
      // push new version and tag
      await exec('git', ['push', 'origin', `HEAD:${inputBranch}`, '--tags'])

      // set output version
      core.setOutput('version', version);
    }
    catch (error) {
      core.setFailed(error.message);

    }
  }
});