Refactor to avoid double unescape

7ammer · May 25, 2015 · 8126cec · 8126cec
1 parent bdfe868
commit 8126cec
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Showing 2 changed files with 47 additions and 12 deletions.
diff --git a/index.js b/index.js
@@ -6,6 +6,14 @@
  * Licensed under the MIT license.
  */
 
+var chars = {
+  '&amp;': '&',
+  '&quot;': '"',
+  '&#39;': '\'',
+  '&lt;': '<',
+  '&gt;': '>'
+};
+
 /**
  * Escape special characters in the given string of html.
  *
@@ -14,12 +22,20 @@
  */
 module.exports = {
   escape: function(html) {
-    return String(html)
-      .replace(/&/g, '&amp;')
-      .replace(/"/g, '&quot;')
-      .replace(/'/g, '&#39;')
-      .replace(/</g, '&lt;')
-      .replace(/>/g, '&gt;');
+    if (!html) {
+      return '';
+    }
+
+    var values = Object.keys(chars).map(function(key) { return chars[key]; });
+    var re = new RegExp('(' + values.join('|') + ')', 'g');
+
+    return String(html).replace(re, function(match) {
+      for (var key in chars) {
+        if (chars.hasOwnProperty(key) && chars[key] === match) {
+          return key;
+        }
+      }
+    });
   },
 
   /**
@@ -29,11 +45,14 @@ module.exports = {
    * @return {String}
    */
   unescape: function(html) {
-    return String(html)
-      .replace(/&amp;/g, '&')
-      .replace(/&quot;/g, '"')
-      .replace(/&#39;/g, '\'')
-      .replace(/&lt;/g, '<')
-      .replace(/&gt;/g, '>');
+    if (!html) {
+      return '';
+    }
+
+    var re = new RegExp('(' + Object.keys(chars).join('|') + ')', 'g');
+
+    return String(html).replace(re, function(match) {
+      return chars[match];
+    });
   }
 };
diff --git a/test/index.js b/test/index.js
@@ -23,6 +23,12 @@ describe('#escape', function() {
   it('converts > into &gt;', function() {
     escape('>').should.equal('&gt;');
   });
+
+  it('returns empty string if called with falsey value', function() {
+    escape().should.equal('');
+    escape('').should.equal('');
+    escape(null).should.equal('');
+  });
 });
 
 describe('#unescape', function() {
@@ -45,4 +51,14 @@ describe('#unescape', function() {
   it('converts &gt; into >', function() {
     unescape('&gt;').should.equal('>');
   });
+
+  it('does not double unescape values', function() {
+    unescape('&amp;quot;').should.equal('&quot;');
+  });
+
+  it('returns empty string if called with falsey value', function() {
+    unescape().should.equal('');
+    unescape('').should.equal('');
+    unescape(null).should.equal('');
+  });
 });