BODY element is always shown/displayed.

related section in the W3C spec:
https://dvcs.w3.org/hg/webdriver/raw-file/default/webdriver-spec.html#determining-if-an-element-is-displayed

Author: sevaseva

javascript/atoms/dom.js

@@ -559,6 +559,12 @@ bot.dom.isShown = function(elem, opt_ignoreOpacity) {
     throw new Error('Argument to isShown must be of type Element');
   }
 
+  // By convention, BODY element is always shown: BODY represents the document
+  // and even if there's nothing rendered in there, user can always see there's the document.
+  if (bot.dom.isElement(elem, goog.dom.TagName.BODY)) {
+    return true;
+  }
+
   // Option or optgroup is shown iff enclosing select is shown (ignoring the
   // select's opacity).
   if (bot.dom.isElement(elem, goog.dom.TagName.OPTION) ||

javascript/atoms/test/shown_test.html

@@ -40,9 +40,9 @@
       expectedFailures = new goog.testing.ExpectedFailures();
     }
 
-
     function tearDown() {
       expectedFailures.handleTearDown();
+      goog.style.setStyle(document.body, 'display', 'block');
       goog.style.setStyle(document.body, 'overflow', 'auto');
     }
 
@@ -52,6 +52,15 @@
       });
     }
 
+    function testBodyShown() {
+      assertTrue(isShown(document.body));
+    }
+
+    function testBodyAlwaysShown() {
+      goog.style.setStyle(document.body, 'display', 'none');
+      assertTrue("BODY element must *always* be shown", isShown(document.body));
+    }
+
     function testCanDetermineIfAnElementIsShownOrNot() {
       assertTrue(isShown(findElement({id: 'displayed'})));
       assertFalse(isShown(findElement({id: 'none'})));