refactor(middleware): update lib/middleware/source_files to ES6

lib/middleware/source_files.js

@@ -1,31 +1,28 @@
-var querystring = require('querystring')
-var _ = require('lodash')
+'use strict'
 
-var common = require('./common')
-var logger = require('../logger')
-var log = logger.create('middleware:source-files')
+const querystring = require('querystring')
+const common = require('./common')
 
-// Files is a Set
-var findByPath = function (files, path) {
-  return _.find(Array.from(files), function (file) {
-    return file.path === path
-  })
+const log = require('../logger').create('middleware:source-files')
+
+function findByPath (files, path) {
+  return Array.from(files).find((file) => file.path === path)
 }
 
-var composeUrl = function (url, basePath, urlRoot, mustEscape) {
-  return (mustEscape ? querystring.unescape(url) : url)
+function composeUrl (url, basePath, urlRoot) {
+  return url
     .replace(urlRoot, '/')
     .replace(/\?.*$/, '')
     .replace(/^\/absolute/, '')
     .replace(/^\/base/, basePath)
 }
 
 // Source Files middleware is responsible for serving all the source files under the test.
-var createSourceFilesMiddleware = function (filesPromise, serveFile, basePath, urlRoot) {
+function createSourceFilesMiddleware (filesPromise, serveFile, basePath, urlRoot) {
   return function (request, response, next) {
-    var requestedFilePath = composeUrl(request.url, basePath, urlRoot, true)
+    const requestedFilePath = composeUrl(request.url, basePath, urlRoot)
     // When a path contains HTML-encoded characters (e.g %2F used by Jenkins for branches with /)
-    var requestedFilePathUnescaped = composeUrl(request.url, basePath, urlRoot, false)
+    const requestedFilePathUnescaped = composeUrl(querystring.unescape(request.url), basePath, urlRoot)
 
     request.pause()
 
@@ -34,18 +31,15 @@ var createSourceFilesMiddleware = function (filesPromise, serveFile, basePath, u
 
     return filesPromise.then(function (files) {
       // TODO(vojta): change served to be a map rather then an array
-      var file = findByPath(files.served, requestedFilePath) ||
-                 findByPath(files.served, requestedFilePathUnescaped)
-      var rangeHeader = request.headers['range']
+      const file = findByPath(files.served, requestedFilePath) || findByPath(files.served, requestedFilePathUnescaped)
+      const rangeHeader = request.headers['range']
 
       if (file) {
         serveFile(file.contentPath || file.path, rangeHeader, response, function () {
           if (/\?\w+/.test(request.url)) {
-            // files with timestamps - cache one year, rely on timestamps
-            common.setHeavyCacheHeaders(response)
+            common.setHeavyCacheHeaders(response) // files with timestamps - cache one year, rely on timestamps
           } else {
-            // without timestamps - no cache (debug)
-            common.setNoCacheHeaders(response)
+            common.setNoCacheHeaders(response) // without timestamps - no cache (debug)
           }
         }, file.content, file.doNotCache)
       } else {
@@ -61,5 +55,4 @@ createSourceFilesMiddleware.$inject = [
   'filesPromise', 'serveFile', 'config.basePath', 'config.urlRoot'
 ]
 
-// PUBLIC API
 exports.create = createSourceFilesMiddleware