In SafariDriver's page script, copy window properties to goog.global.

When the page script is injected, it's called with an empty 'this'
object to avoid polluting the global namespace of the page under
test. However, some Closure libraries look for properties on
goog.global and fall back to worse or slower versions if those
properties are absent.

The specific motivating case is that if goog.async.nextTick can't find
goog.global.MessageChannel, it will fall back to a method that injects
an invisible iframe into the DOM. The page script's use of nextTick
would cause it to create an iframe in the DOM of the page under test,
which we'd like to avoid.

Signed-off-by: Seva Lotoshnikov <[email protected]>

Author: juangj

java/client/test/org/openqa/selenium/safari/CleanSessionTest.java

@@ -20,6 +20,7 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
+import org.openqa.selenium.By;
 import org.openqa.selenium.Cookie;
 import org.openqa.selenium.JavascriptExecutor;
 import org.openqa.selenium.remote.DesiredCapabilities;
@@ -107,6 +108,15 @@ public void doesNotLeakInternalMessagesToThePageUnderTest() {
     assertEquals(1L, numMessages);
   }
 
+  @Test
+  public void doesNotCreateExtraIframeOnPageUnderTest() {
+    driver.get(appServer.whereIs("messages.html"));
+    assertEquals(0, driver.findElements(By.tagName("iframe")).size());
+
+    ((JavascriptExecutor) driver).executeScript("return location.href;");
+    assertEquals(0, driver.findElements(By.tagName("iframe")).size());
+  }
+
   private void assertHasCookie(Cookie cookie) {
     assertTrue(driver.manage().getCookies().contains(cookie));
   }

javascript/safari-driver/inject/page/page.js

@@ -63,6 +63,14 @@ safaridriver.inject.page.encoder;
 safaridriver.inject.page.init = function() {
   goog.debug.LogManager.getRoot().setLevel(goog.debug.Logger.Level.INFO);
 
+  // The page script is installed with an empty 'this' object, to avoid
+  // polluting the global namespace. But we still want Closure libraries to be
+  // able to read the properties of window that would normally be in
+  // goog.global, so we copy those into goog.global.
+  if (window != goog.global) {
+    copyWindowPropertiesTo(goog.global);
+  }
+
   var handler = new safaridriver.logging.ForwardingHandler(window);
   handler.captureConsoleOutput();
 
@@ -97,6 +105,17 @@ safaridriver.inject.page.init = function() {
       return oldFn.toString();
     };
   }
+
+  function copyWindowPropertiesTo(obj) {
+    goog.array.forEach(Object.getOwnPropertyNames(window), function(name) {
+      if (!(name in obj)) {
+        var descriptor = Object.getOwnPropertyDescriptor(window, name);
+        if (descriptor) {
+          Object.defineProperty(obj, name, descriptor);
+        }
+      }
+    });
+  }
 };
 goog.exportSymbol('init', safaridriver.inject.page.init);