github-create-release.js

const formatBasicAuthHeader = require('@quarterto/format-basic-auth-header');
const url = require('url');
const fetch = require('node-fetch');

const errorIsAlreadyExists = ({code}) => code === 'already_exists';

module.exports = ({version, repository, commit, user, pass}) => {
  const githubReleaseCreateEndpoint = url.format({
    protocol: 'https',
    hostname: 'api.github.com',
    pathname: `/repos/${repository}/releases`,
  });
  
  return fetch(githubReleaseCreateEndpoint, {
    method: 'POST',
    body: JSON.stringify({tag_name: version, commitish: commit}),
    headers: {
      'content-type': 'application/json',
      'authorization': formatBasicAuthHeader(user, pass),
    }
  }).then(r => {
    if(!r.ok) {
      return r.text().then(text => {
        try {
          const data = JSON.parse(text);
          if(data.errors && data.errors.some(errorIsAlreadyExists)) {
            return `version ${version} already exists on Github`;
          } 
        } catch(e) {}
        
        throw new Error(`Github returned ${r.status} ${r.statusText}:
${text}`);
      });
    }
    
    return `created version ${version} on Github`;
  });
}