Fix eslint issues, add jsdoc

lib/plugin-loader.js

@@ -1,7 +1,12 @@
 'use strict';
 
-let Path = require('path');
+const Path = require('path');
 
+/**
+ * Requires a module.
+ * @param {*} path the module's path
+ * @return {Object}
+ */
 function try_load(path) {
   try {
     return require(path);
@@ -13,6 +18,17 @@ function try_load(path) {
   }
 }
 
+/**
+ * Load a plugin following the rules
+ * - First try to load from the internal directory plugins (which will disappear soon or later).
+ * - A seccond attempt from node_modules, in case to have multiple match as for instance verdaccio-ldap
+ * and sinopia-ldap. All verdaccio prefix will have preferences.
+ * @param {*} config a reference of the configuration settings
+ * @param {*} plugin_configs
+ * @param {*} params a set of params to initialise the plugin
+ * @param {*} sanity_check callback that check the shape that should fulfill the plugin
+ * @return {Array} list of plugins
+ */
 function load_plugins(config, plugin_configs, params, sanity_check) {
   let plugins = Object.keys(plugin_configs || {}).map(function(p) {
     let plugin;

lib/search.js

@@ -1,3 +1,5 @@
+/* eslint no-invalid-this: "off" */
+
 'use strict';
 
 const lunr = require('lunr');

lib/status-cats.js

@@ -1,3 +1,5 @@
+/* eslint prefer-rest-params: "off" */
+
 'use strict';
 
 // see https://secure.flickr.com/photos/girliemac/sets/72157628409467125

lib/utils.js

@@ -97,23 +97,25 @@ function filter_tarball_urls(pkg, req, config) {
 		if (!req.headers.host) {
 			return _url;
 		}
-		let filename = URL.parse(_url).pathname.replace(/^.*\//, '');
+		const filename = URL.parse(_url).pathname.replace(/^.*\//, '');
 		let result;
 		if (config.url_prefix != null) {
 			result = config.url_prefix.replace(/\/$/, '');
 		} else {
-			result = req.protocol + '://' + req.headers.host;
+			result = `${req.protocol}://${req.headers.host}`;
 		}
 		return `${result}/${pkg.name.replace(/\//g, '%2f')}/-/${filename}`;
 	};
 
 	for (let ver in pkg.versions) {
-		let dist = pkg.versions[ver].dist;
+		if (Object.prototype.hasOwnProperty.call(pkg.versions, ver)) {
+			const dist = pkg.versions[ver].dist;
 			if (dist != null && dist.tarball != null) {
 				// dist.__verdaccio_orig_tarball = dist.tarball
 				dist.tarball = filter(dist.tarball);
 			}
 		}
+	}
 	return pkg;
 }
 
@@ -227,7 +229,6 @@ function semver_sort(array) {
  */
 function normalize_dist_tags(data) {
 	let sorted;
-
 	if (!data['dist-tags'].latest) {
 		// overwrite latest with highest known version based on semver sort
 		sorted = module.exports.semver_sort(Object.keys(data.versions));