improve containsDotFile and only run if necessary

benchmarks/containsDotFile.js

@@ -0,0 +1,15 @@
+'use strict'
+
+const benchmark = require('benchmark')
+const { containsDotFile } = require('../lib/containsDotFile')
+
+const hasDotFileSimple = '.github'.split('/')
+const hasDotFile = './.github'.split('/')
+const noDotFile = './index.html'.split('/')
+
+new benchmark.Suite()
+  .add(hasDotFileSimple.join('/'), function () { containsDotFile(hasDotFileSimple) }, { minSamples: 100 })
+  .add(noDotFile.join('/'), function () { containsDotFile(noDotFile) }, { minSamples: 100 })
+  .add(hasDotFile.join('/'), function () { containsDotFile(hasDotFile) }, { minSamples: 100 })
+  .on('cycle', function onCycle (event) { console.log(String(event.target)) })
+  .run({ async: false })

lib/SendStream.js

@@ -71,6 +71,12 @@ const ERROR_RESPONSES = {
   500: createHtmlDocument('Error', 'Internal Server Error')
 }
 
+const validDotFilesOptions = [
+  'allow',
+  'ignore',
+  'deny'
+]
+
 /**
  * Initialize a `SendStream` with the given `path`.
  *
@@ -105,10 +111,10 @@ function SendStream (req, path, options) {
     : true
 
   this._dotfiles = opts.dotfiles !== undefined
-    ? opts.dotfiles
-    : 'ignore'
+    ? validDotFilesOptions.indexOf(opts.dotfiles)
+    : 1 // 'ignore'
 
-  if (this._dotfiles !== 'ignore' && this._dotfiles !== 'allow' && this._dotfiles !== 'deny') {
+  if (this._dotfiles === -1) {
     throw new TypeError('dotfiles option must be "allow", "deny", or "ignore"')
   }
 
@@ -548,16 +554,25 @@ SendStream.prototype.pipe = function pipe (res) {
   }
 
   // dotfile handling
-  if (containsDotFile(parts)) {
-    debug('%s dotfile "%s"', this._dotfiles, path)
+  if (
+    (
+      debug.enabled || // if debugging is enabled, then check for all cases to log allow case
+      this._dotfiles !== 0 // if debugging is not enabled, then only check if 'deny' or 'ignore' is set
+    ) &&
+    containsDotFile(parts)
+  ) {
     switch (this._dotfiles) {
-      case 'allow':
+      /* istanbul ignore next: unreachable, because NODE_DEBUG can not be set after process is running */
+      case 0: // 'allow'
+        debug('allow dotfile "%s"', path)
         break
-      case 'deny':
+      case 2: // 'deny'
+        debug('deny dotfile "%s"', path)
         this.error(403)
         return res
-      case 'ignore':
+      case 1: // 'ignore'
       default:
+        debug('ignore dotfile "%s"', path)
         this.error(404)
         return res
     }

lib/containsDotFile.js

@@ -11,13 +11,13 @@
  * @api private
  */
 function containsDotFile (parts) {
-  for (let i = 0; i < parts.length; i++) {
-    const part = parts[i]
-    if (part.length > 1 && part[0] === '.') {
+  for (let i = 0, il = parts.length; i < il; ++i) {
+    if (parts[i].length !== 1 && parts[i][0] === '.') {
       return true
     }
   }
 
   return false
 }
-exports.containsDotFile = containsDotFile
+
+module.exports.containsDotFile = containsDotFile

test/containsDotFile.test.js

@@ -0,0 +1,18 @@
+'use strict'
+
+const { test } = require('tap')
+const { containsDotFile } = require('../lib/containsDotFile')
+
+test('containsDotFile', function (t) {
+  const testCases = [
+    ['/.github', true],
+    ['.github', true],
+    ['index.html', false],
+    ['./index.html', false]
+  ]
+  t.plan(testCases.length)
+
+  for (let i = 0; i < testCases.length; ++i) {
+    t.strictSame(containsDotFile(testCases[i][0].split('/')), testCases[i][1], testCases[i][0])
+  }
+})