rewrite "less" test to work when deployed

packages/less/less_tests.js

@@ -1,20 +1,23 @@
 
 Tinytest.add("less - presence", function(test) {
 
-  // find the .less stylesheet, whose first rule contains "less-tests"
-  // in the selector
-  var sheet = _.find(document.styleSheets, function(sh) {
-    var rules = sh.cssRules || sh.rules;
-    return /less-tests/.test(rules[0].selectorText);
-  });
+  var div = document.createElement("DIV");
+  div.style.height = '0';
+  div.style.overflow = 'hidden';
+  div.innerHTML = '<p class="unlucky-left-border"></p>';
+  document.body.appendChild(div);
 
-  test.isTrue(sheet);
+  var p = div.firstChild;
+  var leftBorder;
+  if (p.currentStyle) { // IE
+    leftBorder = p.currentStyle.borderLeftWidth;
+  } else {
+    leftBorder =
+      window.getComputedStyle(p, null).getPropertyValue('border-left-width');
+  }
 
-  // `cssRules` is the W3C name, but isn't supported in IE until
-  // version 9.  IE<=8 has `rules`.  We prefer `cssRules` as
-  // it is less likely to have quirks if both are present.
-  var rules = sheet.cssRules || sheet.rules;
+  test.equal(leftBorder, "13px");
 
-  test.equal(rules[1].style.borderLeftWidth, "13px");
+  div.parentNode.removeChild(div);
 });
 

packages/less/less_tests.less

@@ -4,5 +4,5 @@
 @unlucky: 13px;
 
 .unlucky-left-border {
-  border-left-width: @unlucky;
+  border-left: @unlucky solid white;
 }