react-native/ReactAndroid/src/androidTest/java/com/facebook/react/tests/LayoutEventsTestCase.java

/**
 * 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 com.facebook.react.testing.ReactAppInstrumentationTestCase;
import com.facebook.react.testing.ReactInstanceSpecForTest;
import com.facebook.react.testing.StringRecordingModule;

/**
 * Simple test to verify that layout events (onLayout) propagate to JS from native.
 */
public class LayoutEventsTestCase extends ReactAppInstrumentationTestCase {

  private StringRecordingModule mStringRecordingModule;

  @Override
  protected String getReactApplicationKeyUnderTest() {
    return "LayoutEventsTestApp";
  }

  /**
   * Creates a UI in JS and verifies the onLayout handler is called.
   */
  public void testOnLayoutCalled() {
    assertEquals(3, mStringRecordingModule.getCalls().size());
    assertEquals("10,10-100x100", mStringRecordingModule.getCalls().get(0));
    assertEquals("10,10-50x50", mStringRecordingModule.getCalls().get(1));
    assertEquals("0,0-50x50", mStringRecordingModule.getCalls().get(2));
  }

  @Override
  protected ReactInstanceSpecForTest createReactInstanceSpecForTest() {
    mStringRecordingModule = new StringRecordingModule();
    return super.createReactInstanceSpecForTest()
        .addNativeModule(mStringRecordingModule);
  }
}