java: add ExpectedConditions#numberOfWindowsToBe

Also, clean up unit tests in ExpectedConditionsTest: when an exception is expected to be thrown,
there's no need to make an assertion on the return value.

Signed-off-by: Daniel Davison <[email protected]>

Author: alb-i986

java/client/src/org/openqa/selenium/support/ui/ExpectedConditions.java

@@ -847,6 +847,24 @@ public String toString() {
     };
   }
 
+  public static ExpectedCondition<Boolean> numberOfwindowsToBe(final int expectedNumberOfWindows) {
+    return new ExpectedCondition<Boolean>() {
+      @Override
+      public Boolean apply(WebDriver driver) {
+        try {
+          return driver.getWindowHandles().size() == expectedNumberOfWindows;
+        } catch (WebDriverException e) {
+          return null;
+        }
+      }
+
+      @Override
+      public String toString() {
+        return "number of open windows to be " + expectedNumberOfWindows;
+      }
+    };
+  }
+
   /**
    * An expectation with the logical opposite condition of the given condition.
    *

java/client/test/org/openqa/selenium/support/ui/ExpectedConditionsTest.java

@@ -34,8 +34,10 @@
 import static org.openqa.selenium.support.ui.ExpectedConditions.visibilityOf;
 import static org.openqa.selenium.support.ui.ExpectedConditions.visibilityOfAllElements;
 import static org.openqa.selenium.support.ui.ExpectedConditions.visibilityOfAllElementsLocatedBy;
+import static org.openqa.selenium.support.ui.ExpectedConditions.numberOfwindowsToBe;
 
 import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -48,9 +50,11 @@
 import org.openqa.selenium.StaleElementReferenceException;
 import org.openqa.selenium.TimeoutException;
 import org.openqa.selenium.WebDriver;
+import org.openqa.selenium.WebDriverException;
 import org.openqa.selenium.WebElement;
 
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.TimeUnit;
 
 /**
@@ -432,14 +436,41 @@ public void waitingElementSelectionStateToBeFalseReturnsTrue() {
   public void waitingElementSelectionStateToBeThrowsTimeoutExceptionWhenStateDontMatch() {
     when(mockElement.isSelected()).thenReturn(true);
 
-    assertTrue(wait.until(elementSelectionStateToBe(mockElement, false)));
+    wait.until(elementSelectionStateToBe(mockElement, false));
   }
 
   @Test(expected = StaleElementReferenceException.class)
   public void waitingElementSelectionStateToBeThrowsStaleExceptionWhenElementIsStale() {
     when(mockElement.isSelected()).thenThrow(new StaleElementReferenceException("Stale element"));
 
-    assertTrue(wait.until(elementSelectionStateToBe(mockElement, false)));
+    wait.until(elementSelectionStateToBe(mockElement, false));
+  }
+
+  @Test
+  public void waitingNumberOfWindowsToBeTwoWhenThereAreTwoWindowsOpen() {
+    Set<String> twoWindowHandles = Sets.newHashSet("w1", "w2");
+    when(mockDriver.getWindowHandles()).thenReturn(twoWindowHandles);
+
+    assertTrue(wait.until(numberOfwindowsToBe(2)));
+  }
+
+  @Test(expected = TimeoutException.class)
+  public void waitingNumberOfWindowsToBeTwoThrowsTimeoutExceptionWhenThereAreThreeWindowsOpen() {
+    Set<String> threeWindowHandles = Sets.newHashSet("w1", "w2", "w3");
+    when(mockDriver.getWindowHandles()).thenReturn(threeWindowHandles);
+
+    wait.until(numberOfwindowsToBe(2));
+
+    // then TimeoutException is thrown
+  }
+
+  @Test(expected = TimeoutException.class)
+  public void waitingNumberOfWindowsToBeThrowsTimeoutExceptionWhenGetWindowHandlesThrowsWebDriverException() {
+    when(mockDriver.getWindowHandles()).thenThrow(WebDriverException.class);
+
+    wait.until(numberOfwindowsToBe(2));
+
+    // then TimeoutException is thrown
   }
 
   interface GenericCondition extends ExpectedCondition<Object> {}