markdown-magic-install-command/index.js

Print install command for markdown file

const fs = require("fs");
const path = require("path");
const findup = require("findup");

const defaults = {
  flags: '["--save"]',
  peers: true,
  exact: false,
};

npmFlagsToYarn = {
  "--save": "",
  "---save-exact": "--exact",
  "--save-optional": "--optional",
  "--save-dev": "--dev",
  "--global": "",
};

function quoteSpacesInDep(dep) {
  return dep.includes(" ") ? `"${dep}"` : dep;
}

function filterAndJoin(array, join = " ") {
  return array.filter((v) => !!v).join(join);
}

function findPkg(dir) {
  try {
    return path.join(findup.sync(dir, "package.json"), "package.json");
  } catch (err) {
    console.log(err);
    throw new Error("No package.json file found");
  }
}

function pickClient(dir) {
  return fs.existsSync(path.join(dir, "yarn.lock")) ? "yarn" : "npm";
}

function buildDeps(pkg, exactFlag, peersFlag) {
  const mainDep = filterAndJoin([pkg.name, exactFlag ? pkg.version : ""], "@");

  if (!peersFlag) return mainDep;

  const pkgPeers = pkg.peerDependencies;
  if (!pkgPeers) return mainDep;

  const peers = Object.keys(pkg.peerDependencies).map(buildDep(pkgPeers));

  return filterAndJoin([mainDep, ...peers]);
}

const buildDep = (obj) => (key) => quoteSpacesInDep([key, obj[key]].join("@"));

function buildInstallCmd(client, isGlobal) {
  const install = [client];
  if (isGlobal && client === "yarn") install.push("global");
  install.push(client === "yarn" ? "add" : "install");
  return filterAndJoin(install);
}

function buildCmdFlags(client, flags) {
  let response = flags;

  if (client === "yarn") {
    response = flags.map((flag) => {
      if (Object.prototype.hasOwnProperty.call(npmFlagsToYarn, flag)) {
        return npmFlagsToYarn[flag];
      }

      return flag;
    });
  }

  return filterAndJoin(response);
}

function INSTALLCMD(content, _options = {}, config = {}) {
  const options = Object.assign({}, defaults, _options);
  options.flags = JSON.parse(options.flags);

  let pkgPath;

  if (options.pkg) {
    pkgPath = path.resolve(path.dirname(config.originalPath), options.pkg);
  } else {
    pkgPath = findPkg(config.originalPath);
  }

  const pkg = JSON.parse(fs.readFileSync(pkgPath, "utf8"));
  const client = options.client || pickClient(path.dirname(pkgPath));

  const deps = buildDeps(pkg, options.exact, options.peers !== "false");
  const installCmd = buildInstallCmd(client, options.flags.global);
  const installFlags = buildCmdFlags(client, options.flags);

  const install = filterAndJoin([installCmd, installFlags, deps]);

  return ["```sh", install, "```"].join("\n");
}

module.exports = INSTALLCMD;

if (require.main === module)
  console.log(INSTALLCMD("", undefined, { originalPath: __filename }));