perf(system): improve commonFileName, commonFileExt, fileType, directoryPath performance

fixes #822

1 files changed, 70 insertions, 62 deletions

diff --git a/lib/system.js b/lib/system.js
index f3428271..564d46c0 100644
--- a/lib/system.js
+++ b/lib/system.js
@@ -1,27 +1,72 @@
 // generates fake data for many computer systems properties
 
+var commonFileTypes = [
+  "video",
+  "audio",
+  "image",
+  "text",
+  "application"
+];
+
+var commonMimeTypes = [
+  "application/pdf",
+  "audio/mpeg",
+  "audio/wav",
+  "image/png",
+  "image/jpeg",
+  "image/gif",
+  "video/mp4",
+  "video/mpeg",
+  "text/html"
+];
+
+function setToArray(set) {
+  // shortcut if Array.from is available
+  if (Array.from) { return Array.from(set); }
+
+  var array = [];
+  set.forEach(function (item) {
+    array.push(item);
+  });
+  return array;
+}
+
 /**
  *
  * @namespace faker.system
  */
-function System (faker) {
+function System(faker) {
+  var typeSet = new Set();
+  var extensionSet = new Set();
+  var mimeTypes = faker.definitions.system.mimeTypes;
+
+  Object.keys(mimeTypes).forEach(function (m) {
+    var type = m.split("/")[0];
+
+    typeSet.add(type);
+
+    if (mimeTypes[m].extensions instanceof Array) {
+      mimeTypes[m].extensions.forEach(function (ext) {
+        extensionSet.add(ext);
+      });
+    }
+  });
+
+  var types = setToArray(typeSet);
+  var extensions = setToArray(extensionSet);
+  var mimeTypeKeys = Object.keys(faker.definitions.system.mimeTypes);
+
 
   /**
-   * generates a file name with extension or optional type
+   * generates a file name
    *
    * @method faker.system.fileName
-   * @param {string} ext
-   * @param {string} type
    */
-  this.fileName = function (ext, type) {
-    var str = faker.fake("{{random.words}}.{{system.fileExt}}");
-    str = str.replace(/ /g, '_');
-    str = str.replace(/\,/g, '_');
-    str = str.replace(/\-/g, '_');
-    str = str.replace(/\\/g, '_');
-    str = str.replace(/\//g, '_');
-    str = str.toLowerCase();
-    return str;
+  this.fileName = function () {
+    var str = faker.random.words() + "." + faker.system.fileExt();
+    return str
+        .toLowerCase()
+        .replace(/\W/g, "_");
   };
 
   /**
@@ -29,17 +74,12 @@ function System (faker) {
    *
    * @method faker.system.commonFileName
    * @param {string} ext
-   * @param {string} type
    */
-  this.commonFileName = function (ext, type) {
+  this.commonFileName = function (ext) {
     var str = faker.random.words() + "." + (ext || faker.system.commonFileExt());
-    str = str.replace(/ /g, '_');
-    str = str.replace(/\,/g, '_');
-    str = str.replace(/\-/g, '_');
-    str = str.replace(/\\/g, '_');
-    str = str.replace(/\//g, '_');
-    str = str.toLowerCase();
-    return str;
+    return str
+        .toLowerCase()
+        .replace(/\W/g, "_");
   };
 
   /**
@@ -48,7 +88,7 @@ function System (faker) {
    * @method faker.system.mimeType
    */
   this.mimeType = function () {
-    return faker.random.arrayElement(Object.keys(faker.definitions.system.mimeTypes));
+    return faker.random.arrayElement(mimeTypeKeys);
   };
 
   /**
@@ -57,29 +97,16 @@ function System (faker) {
    * @method faker.system.commonFileType
    */
   this.commonFileType = function () {
-    var types = ['video', 'audio', 'image', 'text', 'application'];
-    return faker.random.arrayElement(types)
+    return faker.random.arrayElement(commonFileTypes);
   };
 
   /**
-   * returns a commonly used file extension based on optional type
+   * returns a commonly used file extension
    *
    * @method faker.system.commonFileExt
-   * @param {string} type
    */
-  this.commonFileExt = function (type) {
-    var types = [
-      'application/pdf',
-      'audio/mpeg',
-      'audio/wav',
-      'image/png',
-      'image/jpeg',
-      'image/gif',
-      'video/mp4',
-      'video/mpeg',
-      'text/html'
-    ];
-    return faker.system.fileExt(faker.random.arrayElement(types));
+  this.commonFileExt = function () {
+    return faker.system.fileExt(faker.random.arrayElement(commonMimeTypes));
   };
 
 
@@ -89,14 +116,6 @@ function System (faker) {
    * @method faker.system.fileType
    */
   this.fileType = function () {
-    var types = [];
-    var mimes = faker.definitions.system.mimeTypes;
-    Object.keys(mimes).forEach(function(m){
-      var parts = m.split('/');
-      if (types.indexOf(parts[0]) === -1) {
-        types.push(parts[0]);
-      }
-    });
     return faker.random.arrayElement(types);
   };
 
@@ -107,23 +126,12 @@ function System (faker) {
    * @param {string} mimeType
    */
   this.fileExt = function (mimeType) {
-    var exts = [];
-    var mimes = faker.definitions.system.mimeTypes;
-
-    // get specific ext by mime-type
-    if (typeof mimes[mimeType] === "object") {
+    if (mimeType) {
+      var mimes = faker.definitions.system.mimeTypes;
       return faker.random.arrayElement(mimes[mimeType].extensions);
     }
 
-    // reduce mime-types to those with file-extensions
-    Object.keys(mimes).forEach(function(m){
-      if (mimes[m].extensions instanceof Array) {
-        mimes[m].extensions.forEach(function(ext){
-          exts.push(ext)
-        });
-      }
-    });
-    return faker.random.arrayElement(exts);
+    return faker.random.arrayElement(extensions);
   };
 
   /**