added Tester.assertElementCount()

@@ -281,6 +281,35 @@ Tester.prototype.assertNotEquals = function assertNotEquals(subject, shouldnt, m
 };
 
 /**
+ * Asserts that a selector expression matches n elements.
+ *
+ * @param  Mixed   selector  A selector expression
+ * @param  Number  count     Expected number of matching elements
+ * @param  String  message   Test description (Optional)
+ * @return Object            An assertion result object
+ */
+Tester.prototype.assertElementCount = function assertElementCount(selector, count, message) {
+    "use strict";
+    if (!utils.isNumber(count) || count < 0) {
+        throw new CasperError('assertElementCount() needs a positive integer count');
+    }
+    return this.assert(this.casper.evaluate(function(selector) {
+        try {
+            return __utils__.findAll(selector).length;
+        } catch (e) {
+            return -1;
+        }
+    }, selector) === count, message, {
+        type: "assertElementCount",
+        standard: f("%d matching element(s) found", count),
+        values: {
+            selector: selector,
+            count:    count
+        }
+    });
+};
+
+/**
  * Asserts that a code evaluation in remote DOM resolves to true.
  *
  * @param  Function  fn       A function to be evaluated in remote DOM

@@ -2,7 +2,7 @@
 /*jshint strict:false maxstatements:99*/
 var fs = require('fs');
 
-casper.test.begin('Common assertions tests', 40, function(test) {
+casper.test.begin('Common assertions tests', 43, function(test) {
     casper.start('tests/site/index.html', function() {
         test.assertTextExists('form', 'Tester.assertTextExists() checks that page body contains text');
         test.assertTextExist('form', 'Tester.assertTextExist() checks that page body contains text [alias]');
@@ -29,6 +29,9 @@ casper.test.begin('Common assertions tests', 40, function(test) {
         test.assertEvalEqual(function() {
             return 42;
         }, 42, 'Tester.assertEvalEqual() works as expected [alias]');
+        test.assertElementCount('ul', 1, 'Tester.assertElementCount() works as expected');
+        test.assertElementCount('li', 3, 'Tester.assertElementCount() works as expected');
+        test.assertElementCount('address', 0, 'Tester.assertElementCount() works as expected');
         test.assertExists('body', 'Tester.assertExists() works as expected');
         test.assertExist('body', 'Tester.assertExist() works as expected [alias]');
         test.assertSelectorExists('body', 'Tester.assertSelectorExists() works as expected [alias]');