<Replace this line with a title. Use 1 line only, 67 chars or less>

Reviewed By: matryoshcow

Differential Revision: D3432084

fbshipit-source-id: fa94b1aca40c931cc273a5561adf37f458aaa0ff

ReactAndroid/src/androidTest/java/com/facebook/react/tests/JSResponderTestCase.java

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+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ * All rights reserved.
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.react.tests;
+
+import android.widget.ScrollView;
+
+import com.facebook.react.uimanager.PixelUtil;
+import com.facebook.react.testing.ReactAppInstrumentationTestCase;
+import com.facebook.react.testing.SingleTouchGestureGenerator;
+
+/**
+ * Test case to verify that JSResponder flow work correctly.
+ *
+ * In a single test case scenario we have a view with pan gesture recognizer containing a scrollview
+ * We werify that by vertical drags affects a scrollview while horizontal drags are suppose to
+ * be recognized by pan responder and setJSResponder should be triggered resulting in scrollview
+ * events being intercepted.
+ */
+public class JSResponderTestCase extends ReactAppInstrumentationTestCase {
+
+  @Override
+  protected String getReactApplicationKeyUnderTest() {
+    return "JSResponderTestApp";
+  }
+
+  public void testResponderLocksScrollView() {
+    ScrollView scrollView = getViewByTestId("scroll_view");
+    assertNotNull(scrollView);
+    assertEquals(0, scrollView.getScrollY());
+
+    float inpx40dp = PixelUtil.toPixelFromDIP(40f);
+    float inpx100dp = PixelUtil.toPixelFromDIP(100f);
+
+    SingleTouchGestureGenerator gestureGenerator = createGestureGenerator();
+
+    gestureGenerator
+        .startGesture(30, 30 + inpx100dp)
+        .dragTo(30 + inpx40dp, 30, 10, 1200)
+        .endGesture(180, 100);
+
+    waitForBridgeAndUIIdle();
+
+    assertTrue("Expected to scroll by at least 80 dp", scrollView.getScrollY() >= inpx100dp * .8f);
+
+    int previousScroll = scrollView.getScrollY();
+
+    gestureGenerator
+        .startGesture(30, 30 + inpx100dp)
+        .dragTo(30 + inpx40dp, 30 + inpx100dp, 10, 1200);
+
+    waitForBridgeAndUIIdle();
+
+    gestureGenerator
+        .dragTo(30 + inpx40dp, 30, 10, 1200)
+        .endGesture();
+
+    waitForBridgeAndUIIdle();
+    assertEquals("Expected not to scroll", scrollView.getScrollY(), previousScroll);
+
+  }
+
+}