move parseBackgroundImage to Util; add tests

src/Core.js

@@ -31,6 +31,26 @@ _html2canvas.Util.backgroundImage = function (src) {
     return src;
 };
 
+_html2canvas.Util.parseBackgroundImage = function (value) {
+    var rxBackgroundImage = /([a-z\-]+)\((("[^"]+)|([^)]+))\)/i,
+        match, results = [], n = 0;
+    if(!value) { return results; }
+
+    while( n++ < 100 && !!(match = value.match(rxBackgroundImage)) ) {
+      var def = match[2];
+      if(def.substr( 0, 1 ) === '"') {
+        def = def.substr(1, def.length-2);
+    }
+    results.push({
+        method: match[1],
+        definition: def,
+        value: match[0]
+    });  
+    value = value.replace( match[0], '' );
+    }  
+    return results;
+};
+
 _html2canvas.Util.Bounds = function getBounds (el) {
     var clientRect,
     bounds = {};

src/Preload.js

@@ -124,7 +124,7 @@ _html2canvas.Preload = function( options ) {
         h2clog("html2canvas: failed to get background-image - Exception: " + e.message);
       }
 
-      background_images = parseBackgroundImage(background_image);
+      background_images = _html2canvas.Util.parseBackgroundImage(background_image);
       while(!!(background_image = background_images.shift())) {
 
         if ( background_image.value && background_image.value !== "1" && background_image.value !== "none" ) {
@@ -153,25 +153,6 @@ _html2canvas.Preload = function( options ) {
     }
   }
 
-  function parseBackgroundImage(value) {
-    var rxBackgroundImage = /([a-z\-]+)\((("[^"]+)|([^)]+))\)/i,
-      match, results = [], n = 0;
-    if(!value) { return results; }
-    while(n++ < 100 && !!(match = value.match(rxBackgroundImage))) {
-      var def = match[2];
-      if(def.substr( 0, 1 ) === '"') {
-         def = def.substr(1, def.length-2);
-      }
-      results.push( {
-        method: match[1],
-        definition: def,
-        value: match[0]
-      } );  
-      value = value.replace( match[0], '' );
-    }  
-    return results;
-  }
-
   function setImageLoadHandlers(img, imageObj) {
     img.onload = function() {
       if ( imageObj.timer !== undefined ) {

tests/qunit/unit/css.js

@@ -145,6 +145,54 @@ $(function() {
         });
     }); 
     
+    test('background-image', function () {
+        test_parse_background_image(
+            'url(test)', 
+            { method: 'url', definition: 'test', value: 'url(test)' }, 
+            'basic url'
+        );
+
+        test_parse_background_image(
+            'url("test")', 
+            { method: 'url', definition: 'test', value: 'url("test")' }, 
+            'quoted url'
+        );
+
+        test_parse_background_image(
+            'url(data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)', 
+            { 
+                method: 'url', 
+                definition: 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7', 
+                value: 'url(data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)' 
+            }, 
+            'data url'
+        );
+
+        test_parse_background_image(
+            'linear-gradient(red,black)', 
+            { method: 'linear-gradient', definition: 'red,black', value: 'linear-gradient(red,black)' }, 
+            'linear-gradient'
+        );
+
+        test_parse_background_image(
+            'linear-gradient(red,black), url(test), url("test")', [
+            { method: 'linear-gradient', definition: 'red,black', value: 'linear-gradient(red,black)' },
+            { method: 'url', definition: 'test', value: 'url(test)' },
+            { method: 'url', definition: 'test', value: 'url("test")' }
+            ],
+            'multiple backgrounds'
+        );
+
+    });
+
+    function test_parse_background_image(value, expected, name) {
+        deepEqual(
+            _html2canvas.Util.parseBackgroundImage(value), 
+            Array.isArray(expected) ? expected : [expected], 
+            name
+        );
+    }
+
     // TODO add backgroundPosition % tests
     
 });