Change SearchContext so that findElements can return a list that sub-classes WebElement

java/client/src/org/openqa/selenium/SearchContext.java

@@ -19,15 +19,15 @@
 
 import java.util.List;
 
-public interface SearchContext {
+public interface SearchContext{
   /**
    * Find all elements within the current context using the given mechanism.
    *
    * @param by The locating mechanism to use
    * @return A list of all {@link WebElement}s, or an empty list if nothing matches
    * @see org.openqa.selenium.By
    */
-  List<WebElement> findElements(By by);
+  <W extends WebElement> List<W> findElements(By by);
 
 
   /**

java/client/test/org/openqa/selenium/SearchContextTest.java

@@ -0,0 +1,72 @@
+package org.openqa.selenium;
+
+import org.junit.Test;
+
+import java.util.List;
+
+// this class just tests we can compile the code
+public class SearchContextTest {
+
+  private final SubClassingSearchContext subClassingSearchContext = new SubClassingSearchContext();
+  private final SameClassSearchContext sameClassSearchContext = new SameClassSearchContext() {
+    @Override
+    public List<WebElement> findElements(By by) {
+      return null;
+    }
+
+    @Override
+    public WebElement findElement(By by) {
+      return null;
+    }
+  };
+
+  private interface TestWebElement extends WebElement {
+
+  }
+
+  private static class SubClassingSearchContext implements SearchContext {
+
+    @Override
+    public List<TestWebElement> findElements(By by) {
+      return null;
+    }
+
+    @Override
+    public TestWebElement findElement(By by) {
+      return null;
+    }
+  }
+
+  private interface SameClassSearchContext extends SearchContext {
+
+  }
+
+  @Test
+  public void makeSureFindElementsIsBackwardsCompatible() throws Exception {
+
+    @SuppressWarnings("unused")
+    List<? extends WebElement> elements = sameClassSearchContext.findElements(null);
+  }
+
+  @Test
+  public void makeSureFindElementIsBackwardsCompatible() throws Exception {
+
+    @SuppressWarnings("unused")
+    WebElement element = sameClassSearchContext.findElement(null);
+  }
+
+  @Test
+  public void makeSureFindElementsCanUseSuperClass() throws Exception {
+    @SuppressWarnings("unused")
+    List<TestWebElement> elements = subClassingSearchContext.findElements(null);
+  }
+
+  @Test
+  public void makeSureFindElementCanUseSuperClass() throws Exception {
+
+    @SuppressWarnings("unused")
+    WebElement element = subClassingSearchContext.findElement(null);
+
+
+  }
+}