Lookup various github stats from npm package name; stars, contributors, open issues/prs etc.

dependency-stats.js

const r2 = require("r2");
const npm = require("npm");
const { spawn } = require("child_process");

const [_, __, accessToken, repo] = process.argv;

const shellCmdStdoutToObject = (cmd, args) =>
  new Promise(function(resolve, reject) {
    const child = spawn(cmd, args);
    let result = "";
    child.stdout.on("data", data => {
      result += data;
    });
    child.stderr.on("data", data => {
      reject(new Error(`Error running cmd "${cmd}" with args "${args}".`));
    });
    child.on("close", code => {
      const fn = new Function(`return ${result.replace(/\r?\n/g, "")}`);
      resolve(fn());
    });
  });

const appendToken = url =>
  url + (url.indexOf("?") > 0 ? "&" : "?") + "access_token=" + accessToken;

const urlToProject = url => {
  const split = url.split("/");
  return (
    split[split.length - 2] + "/" + split[split.length - 1].replace(".git", "")
  );
};

const projectToRepoUrl = p => `https://api.github.com/repos/${p}`;

const fetchRepo = repo =>
  shellCmdStdoutToObject("npm", ["view", repo, "repository"])
    .then(result => result.url)
    .then(urlToProject)
    .then(projectToRepoUrl)
    .then(appendToken)
    .then(r2)
    .then(o => o.json);

const parseParams = params =>
  params
    .split("&")
    .map(keyValue => keyValue.split("="))
    .reduce((acc, [key, value]) => {
      acc[key] = value;
      return acc;
    }, {});

const fetchLastPageNoFor = async (url, params = "") => {
  const pagedUrl = `${url}?per_page=1${params}`;
  const res = await r2(appendToken(pagedUrl)).response;
  const link = res.headers.get("link");
  if (!link) {
    const body = await res.json();
    return body.length;
  }

  const [n] = link
    .split(",")
    .filter(link => link.indexOf('rel="last"') != -1)
    .map(link => link.replace('>; rel="last"', ""))
    .map(link => link.split("?")[1])
    .map(parseParams)
    .map(query => query.page)
    .map(Number);
  return n;
};

const fetchRepoStats = async repoName => {
  const r = await fetchRepo(repoName);

  const commits = fetchLastPageNoFor(r.commits_url.replace("{/sha}", "")),
    contributors = fetchLastPageNoFor(r.contributors_url),
    openPullRequests = fetchLastPageNoFor(r.pulls_url.replace("{/number}", "")),
    closedPullRequests = fetchLastPageNoFor(
      r.pulls_url.replace("{/number}", ""),
      "&state=closed"
    );

  return {
    url: r.html_url,
    repo: r.full_name,
    createdAt: r.created_at,
    stars: r.stargazers_count,
    openIssues: r.open_issues,
    watchers: r.subscribers_count,
    commits: await commits,
    contributors: await contributors,
    openPullRequests: await openPullRequests,
    closedPullRequests: await closedPullRequests
  };
};

(async () => console.log(await fetchRepoStats(repo)))();

result.out

➜  node-dependencies node dependency-stats <token> cerebral
{ url: 'https://github.com/cerebral/cerebral',
  repo: 'cerebral/cerebral',
  createdAt: '2015-05-09T11:40:05Z',
  stars: 1634,
  openIssues: 34,
  watchers: 63,
  commits: 2120,
  contributors: 67,
  openPullRequests: 1,
  closedPullRequests: 936 }
  
➜  node-dependencies node dependency-stats <token> react
{ url: 'https://github.com/facebook/react',
  repo: 'facebook/react',
  createdAt: '2013-05-24T16:15:54Z',
  stars: 112010,
  openIssues: 382,
  watchers: 6369,
  commits: 10306,
  contributors: 446,
  openPullRequests: 96,
  closedPullRequests: 7148 }