Page factory list element not initialized when parameterized by generic type

[JamesSassano]

Description

Given the following class (We have a base screen class that is used for Android and iOS that each specify T as AndroidElement and IOSElement, respectively, where we want to retain the specific platform element type):

 public class ScreenWithLists<T extends MobileElement> {
 public List<MobileElement> listME;
 public List<T> listT;
 }

and initialization with:

 PageFactory.initElements(new AppiumFieldDecorator(driver),
 new ScreenWithLists<MobileElement>()); // Or AndroidElement or IOSElement

The "listT" field does not get initialized as it fails the isDecoratableList check in AppiumFieldDecorator's DefaultFieldDecorator implementation when checking the list's type is one of "availableElementClasses".

Environment

• appium java client build version: 6.1.0
• selenium client build version: 3.12

Details

This generic type may be able to be checked with an additional bounds check in AppiumFieldDecorator's isDecoratableList:

 if ((listType instanceof TypeVariable) &&
 Arrays.asList(((TypeVariable<?>) listType).getBounds())
 .stream().anyMatch(item -> availableElementClasses.contains(item))) {
 return true;
 }

Testing

https://github.com/appium/java-client/blob/master/src/test/java/io/appium/java_client/pagefactory_tests/GenericTest.java
could update the Supplier to:

 TempGenericPage<?> page = new TempGenericPage<>();
 PageFactory
 .initElements(new AppiumFieldDecorator(new MockWebDriver()),
 page);
 return null != page.getItems();

Related issue:

#368

Code To Reproduce Issue [ Good To Have ]

public class ListParameterReproductionTest {
 public static class ScreenWithLists<T> {
 public List<MobileElement> listME;
 public List<T> listT;
 }

 public static void main(String[] args) {
 SearchContext mockSearchContext = new SearchContext() {
 @Override
 public <T extends WebElement> List<T> findElements(By by) {
 return null;
 }

 @Override
 public <T extends WebElement> T findElement(By by) {
 return null;
 }
 };

 ScreenWithLists<MobileElement> screen = new ScreenWithLists<MobileElement>();
 PageFactory.initElements(new AppiumFieldDecorator(mockSearchContext), screen);
 assertNotNull(screen.listME);
 assertNotNull(screen.listT);
 }
}