Function installModuleFromURL

src/install/index.js:174–223

* Install a module in an app given a URL * * @return {Promise } resolves with installed version

(app, name, url, version, opts)

 * @return {Promise<string>} resolves with installed version
 */
function installModuleFromURL (app, name, url, version, opts) {
  // we can't silence a clone/fetch in case the user has to enter credentials
  logger.log(chalk.cyan('Adding ' + name + (version ? '@' + version : '')));

  var modulePath = path.join(app.paths.modules, name);
  var exists = fs.existsSync(modulePath);

  return Promise
    .bind({})
    .then(function () {
      if (!exists) {
        // if destination path doesn't exist, add module to cache then add
        // module to app
        return updateCache(name, url, version)
          .bind(this)
          .then(function (cacheEntry) {
            this.cacheEntry = cacheEntry;
            return addModuleToApp(app, cacheEntry, name, opts);
          });
      }
    })
    .then(function () {
      // modulePath may be invalid if name is a URL, use the cacheEntry for the
      // latest values
      if (this.cacheEntry) {
        name = this.cacheEntry.name;
        modulePath = path.join(app.paths.modules, this.cacheEntry.name);
      }

      if (opts.link) { displayLinkWarning(app, modulePath); }

      return Module.setVersion(modulePath, version, {
        forceInstall: true,
        unsafe: opts.unsafe
      });
    })
    .then(function (installedVersion) {
      this.installedVersion = installedVersion;

      app.reloadModules(); // synchronous
      return app.addDependency(name, {
        url: this.cacheEntry && this.cacheEntry.url,
        version: this.installedVersion
      });
    })
    .then(function () {
      // Return value for installModuleFromURL
      return this.installedVersion;
    });
}

/**
 * Link module into app's moudles folder