Add supporting of masks

Author: eGavr

lib/index.js

@@ -1,7 +1,8 @@
 var _ = require('lodash'),
     HtmlDiff = require('./HtmlDiff'),
     modifyHtmlAccordingToOptions = require('./utils/modify'),
-    defaults = require('./utils/defaults');
+    defaults = require('./utils/defaults'),
+    handleMasks = require('./utils/mask');
 
 /**
  * Tokenizes the given HTML
@@ -11,7 +12,7 @@ var _ = require('lodash'),
 HtmlDiff.prototype.tokenize = function (html) {
     html = modifyHtmlAccordingToOptions(html, this.options);
 
-    return _.filter(html.split(/([{}:;,<>"'\[\]\/]|\s+)/));
+    return _.filter(html.split(/({{.+?[^\\]}}(?!})|[{}=:;,<>"'\[\]\/]|\s+)/));
 };
 
 /**
@@ -40,9 +41,10 @@ var HtmlDiffer = function (options) {
  * @returns {Diff}
  */
 HtmlDiffer.prototype.diffHtml = function (html1, html2) {
-    var htmlDiffer = new HtmlDiff(this.options);
+    var htmlDiffer = new HtmlDiff(this.options),
+        diff = htmlDiffer.diff(html1, html2);
 
-    return htmlDiffer.diff(html1, html2);
+    return handleMasks(diff);
 };
 
 /**

lib/utils/mask.js

@@ -0,0 +1,88 @@
+/**
+ * Mask
+ * ====
+ *
+ * {{RegExp}}
+ */
+var MASK_REGEXP = /(.*){{(.+[^\\])}}(?!})(.*)/;
+
+/**
+ * Checks whether the given part of the diff should be added or removed
+ * @param {Diff} part
+ * @returns {Boolean}
+ */
+function _isDiffPart(part) {
+    return part.added || part.removed;
+}
+
+/**
+ * Removes diff parts which are equal by mask
+ * @param {Diff[]} diff
+ * @returns {Diff[]}
+ */
+function _revealMasks(diff) {
+    for (var i = 0; i < diff.length; i++) {
+        var currPart = diff[i];
+
+        if (!_isDiffPart(currPart)) continue;
+
+        var prevPart = diff[i - 1],
+            nextPart = diff[i + 1],
+            matchedMask = currPart.value.match(MASK_REGEXP);
+
+        if (!matchedMask) continue;
+
+        var regExp = new RegExp('^' + matchedMask[1] + matchedMask[2] + matchedMask[3] + '$');
+        if (currPart.added && nextPart && nextPart.removed) {
+            if (nextPart.value.match(regExp)) {
+                nextPart.removed = undefined;
+                diff.splice(i--, 1);
+            }
+        } else if (currPart.removed && prevPart && prevPart.added) {
+            if (prevPart.value.match(regExp)) {
+                prevPart.added = undefined;
+                diff.splice(i--, 1);
+            }
+        }
+    }
+
+    return diff;
+}
+
+/**
+ * Concats not diff parts which go one by one
+ * @param {Diff[]} diff
+ * @returns {Diff[]}
+ */
+function _concatNotDiffParts(diff) {
+    for (var i = 1; i < diff.length; i++) {
+        var currPart = diff[i],
+            prevPart = diff[i - 1];
+
+        if (!_isDiffPart(currPart) && !_isDiffPart(prevPart)) {
+            prevPart.value += currPart.value;
+
+            diff.splice(i--, 1);
+        }
+    }
+
+    return diff;
+}
+
+/**
+ * @typedef {Object} Diff
+ * @property {String} value
+ * @property {String|undefined} added
+ * @property {String|undefined} removed
+ */
+
+/**
+ * Handles masks in the given diff
+ * @param {Diff[]} diff
+ * @returns {Diff[]}
+ */
+module.exports = function (diff) {
+    diff = _revealMasks(diff);
+
+    return _concatNotDiffParts(diff);
+};