server.js

import { MongoClient } from 'mongodb';
import nodemailer from 'nodemailer';
import { marked } from 'marked';

async function retrieve() {
  const response = await fetch('https://api.github.com/graphql', {
    method: 'POST',
    headers: {
      Authorization: `bearer ${process.env.GITHUB_ACCESS_TOKEN}`
    },
    body: JSON.stringify(
      {
        query: `
          {
            search(type: REPOSITORY, query: "org:${process.env.ORGANISATION}", first: 100) {
              repositoryCount
              edges {
                node {
                  ... on Repository {
                    name
                    description
                    url
                    forkCount
                    stargazers {
                      totalCount
                    }
                    defaultBranchRef {
                      target {
                        ... on Commit {
                          history {
                            totalCount
                          }
                        }
                      }
                    }
                  }
                }
              }
            }
          }
        `
      }
    )
  });
  const json = await response.json();
  return json.data.search.edges.map(({ node }) => {
    const {
      name,
      description,
      url,
      forkCount: forks,
      stargazers: { totalCount: stars }
    } = node;
    const commits = (node.defaultBranchRef && node.defaultBranchRef.target.history.totalCount) || 0;
    return { name, description, url, forks, stars, commits };
  });
}

async function store(rs) {
  const client = await new MongoClient(process.env.MONGO_URL).connect();
  for (const r of rs) {
    const { value } = await client
      .db('trending')
      .collection('repositories')
      .replaceOne({ name: r.name }, r, { upsert: true });
    Object.assign(r, {
      deltaForks: r.forks - ((value && value.forks) || 0),
      deltaStars: r.stars - ((value && value.stars) || 0),
      deltaCommits: r.commits - ((value && value.commits) || 0)
    });
  }
  await client.close();
  return {
    forks: Math.max(...rs.map(r => r.deltaForks)),
    stars: Math.max(...rs.map(r => r.deltaStars)),
    commits: Math.max(...rs.map(r => r.deltaCommits))
  };
}

(async () => {
  const rs = await retrieve();
  const maxDeltas = await store(rs);
  let text = '';
  if (maxDeltas.forks) {
    text +=
      `Most forked (+${maxDeltas.forks}):\n\n` +
      rs
        .filter(r => r.deltaForks === maxDeltas.forks)
        .map(r => `- [${r.name}](${r.url}) (${r.forks})`)
        .join('\n') +
      '\n\n';
  }
  if (maxDeltas.stars) {
    text +=
      `Most starred (+${maxDeltas.stars}):\n\n` +
      rs
        .filter(r => r.deltaStars === maxDeltas.stars)
        .map(r => `- [${r.name}](${r.url}) (${r.stars})`)
        .join('\n') +
      '\n\n';
  }
  if (maxDeltas.commits) {
    text +=
      `Most commits (+${maxDeltas.commits}):\n\n` +
      rs
        .filter(r => r.deltaCommits === maxDeltas.commits)
        .map(r => `- [${r.name}](${r.url}) (${r.commits})`)
        .join('\n') +
      '\n\n';
  }
  if (text) {
    const transporter = nodemailer.createTransport(process.env.SMTP_URL);
    transporter.sendMail({
      from: process.env.EMAIL_FROM,
      to: process.env.EMAIL_TO,
      subject: `Trending repositories for ${process.env.ORGANISATION}`,
      html: marked(text)
    });
  }
})();