Replace the implementation of escapeTextContentForBrowser with escape…

…-html (#6862)

* Replacing the implementation of escapeTextContentForBrowser with escape-html for performance

* Addressing @spicyj's code review comment here: #6862 (comment) . Pulled the code of escape-html in to react and changed the encoding of single quote to &#x27.

* Addressing code review comment #6862 (comment) to make code more inlinable for v8. Thanks, @spicyj.

(cherry picked from commit d6e7058)

src/renderers/dom/shared/escapeTextContentForBrowser.js

@@ -1,29 +1,105 @@
 /**
- * Copyright 2013-present, Facebook, Inc.
+ * Copyright 2016-present, Facebook, Inc.
  * All rights reserved.
  *
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
  *
+ * Based on the escape-html library, which is used under the MIT License below:
+ *
+ * Copyright (c) 2012-2013 TJ Holowaychuk
+ * Copyright (c) 2015 Andreas Lubbe
+ * Copyright (c) 2015 Tiancheng "Timothy" Gu
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * 'Software'), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
  * @providesModule escapeTextContentForBrowser
  */
 
 'use strict';
 
-var ESCAPE_LOOKUP = {
-  '&': '&',
-  '>': '>',
-  '<': '&lt;',
-  '"': '&quot;',
-  '\'': '&#x27;',
-};
+// code copied and modified from escape-html
+/**
+ * Module variables.
+ * @private
+ */
+
+var matchHtmlRegExp = /["'&<>]/;
+
+/**
+ * Escape special characters in the given string of html.
+ *
+ * @param  {string} string The string to escape for inserting into HTML
+ * @return {string}
+ * @public
+ */
+
+function escapeHtml(string) {
+  var str = '' + string;
+  var match = matchHtmlRegExp.exec(str);
+
+  if (!match) {
+    return str;
+  }
 
-var ESCAPE_REGEX = /[&><"']/g;
+  var escape;
+  var html = '';
+  var index = 0;
+  var lastIndex = 0;
 
-function escaper(match) {
-  return ESCAPE_LOOKUP[match];
+  for (index = match.index; index < str.length; index++) {
+    switch (str.charCodeAt(index)) {
+      case 34: // "
+        escape = '&quot;';
+        break;
+      case 38: // &
+        escape = '&amp;';
+        break;
+      case 39: // '
+        escape = '&#x27;';  // modified from escape-html; used to be '&#39'
+        break;
+      case 60: // <
+        escape = '&lt;';
+        break;
+      case 62: // >
+        escape = '&gt;';
+        break;
+      default:
+        continue;
+    }
+
+    if (lastIndex !== index) {
+      html += str.substring(lastIndex, index);
+    }
+
+    lastIndex = index + 1;
+    html += escape;
+  }
+
+  return lastIndex !== index
+    ? html + str.substring(lastIndex, index)
+    : html;
 }
+// end code copied and modified from escape-html
+
 
 /**
  * Escapes text to prevent scripting attacks.
@@ -32,7 +108,13 @@ function escaper(match) {
  * @return {string} An escaped string.
  */
 function escapeTextContentForBrowser(text) {
-  return ('' + text).replace(ESCAPE_REGEX, escaper);
+  if (typeof text === 'boolean' || typeof text === 'number') {
+    // this shortcircuit helps perf for types that we know will never have
+    // special characters, especially given that this function is used often
+    // for numeric dom ids.
+    return '' + text;
+  }
+  return escapeHtml(text);
 }
 
 module.exports = escapeTextContentForBrowser;