Future will fail when the handler which is passed to Future.future throws an Exception. (#3057)

* Future will fail on `Future.future` throws an Exception.

Signed-off-by: iseki <admin@iseki.space>

* Modify testcase and fix format.

Signed-off-by: iseki <admin@iseki.space>

src/main/java/io/vertx/core/Future.java

@@ -36,7 +36,11 @@ public interface Future<T> extends AsyncResult<T> {
    */
   static <T> Future<T> future(Handler<Promise<T>> handler) {
     Promise<T> promise = Promise.promise();
-    handler.handle(promise);
+    try {
+      handler.handle(promise);
+    } catch (Exception e){
+      promise.tryFail(e);
+    }
     return promise.future();
   }
 

src/test/java/io/vertx/core/FutureTest.java

@@ -65,14 +65,10 @@ public class FutureTest extends VertxTestBase {
     assertSame(f2, ref.get().future());
     assertEquals(1, count.get());
     new Checker<>(f2).assertFailed(cause);
-    try {
-      Future.future(f -> {
-        throw cause;
-      });
-      fail();
-    } catch (Exception e) {
-      assertSame(cause, e);
-    }
+    Future f3 = Future.future(f -> {
+      throw cause;
+    });
+    assertSame(cause, f3.cause());
   }
 
   @Test