ExpectedCondition enhancement

TikhomirovSergey · TikhomirovSergey · commit f2b547d6de7b · 2016-12-18T21:14:55.000+03:00
Methods `compose` and `andThen` were overridden the way to prevent NPE occurence.
diff --git a/src/main/java/io/appium/java_client/functions/ExpectedCondition.java b/src/main/java/io/appium/java_client/functions/ExpectedCondition.java
@@ -18,6 +18,10 @@
 
 import org.openqa.selenium.WebDriver;
 
+import java.util.Objects;
+import java.util.Optional;
+import java.util.function.Function;
+
 /**
  * This is extended version of {@link org.openqa.selenium.support.ui.ExpectedCondition}. It is combined
  * with {@link java.util.function.Function}.
@@ -27,4 +31,20 @@
 @FunctionalInterface
 public interface ExpectedCondition<T> extends org.openqa.selenium.support.ui.ExpectedCondition<T>,
         java.util.function.Function<WebDriver, T> {
+
+    @Override default <V> Function<V, T> compose(Function<? super V, ? extends WebDriver> before) {
+        Objects.requireNonNull(before);
+        return (V v) -> {
+            WebDriver driver = before.apply(v);
+            return Optional.ofNullable(driver != null ? apply(driver) : null).orElse(null);
+        };
+    }
+
+    @Override default <V> Function<WebDriver, V> andThen(Function<? super T, ? extends V> after) {
+        Objects.requireNonNull(after);
+        return (WebDriver w) -> {
+            T result = apply(w);
+            return Optional.ofNullable(result != null ? after.apply(result) : null).orElse(null);
+        };
+    }
 }
