ComponentsRule.java

/**
 * Copyright (c) 2017-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.litho.testing;

import android.app.Activity;

import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;
import org.robolectric.Robolectric;

import com.facebook.litho.R;
import com.facebook.litho.ComponentContext;

public class ComponentsRule implements TestRule {

  private ComponentContext mContext;

  @Override
  public Statement apply(final Statement base, final Description description) {
    return new Statement() {
      @Override
      public void evaluate() throws Throwable {
        final Activity activity = Robolectric.buildActivity(Activity.class)
            .create()
            .get();
        mContext = new ComponentContext(activity);
        setComponentStyleableAttributes();

        base.evaluate();
      }
    };
  }

  /**
   * Get a Component Context for this test instance.
   */
  public ComponentContext getContext() {
    return mContext;
  }

  /**
   * TODO natthu: this is just a hack around a BUCK issue whereby BUCK only generates random array
   * values. Component tests require the correct values for the ComponentLayout styleable array in
   * order to bind props to the layout. The array that we define here needs to be kept up-to-date
   * with the array defined in //android_res/com/facebook/components/res/values/attrs.xml.
   */
  static void setComponentStyleableAttributes() {

    System.arraycopy(
      new int[]{
        R.attr.flex_direction,
        R.attr.flex_layoutDirection,
        R.attr.flex_justifyContent,
        R.attr.flex_alignItems,
        R.attr.flex_alignSelf,
        R.attr.flex_positionType,
        R.attr.flex_wrap,
        R.attr.flex_left,
        R.attr.flex_top,
        R.attr.flex_right,
        R.attr.flex_bottom,
        R.attr.flex,
        android.R.attr.layout_width,
        android.R.attr.layout_height,
        android.R.attr.padding,
        android.R.attr.paddingLeft,
        android.R.attr.paddingTop,
        android.R.attr.paddingRight,
        android.R.attr.paddingBottom,
        android.R.attr.paddingStart,
        android.R.attr.paddingEnd,
        android.R.attr.layout_margin,
        android.R.attr.layout_marginLeft,
        android.R.attr.layout_marginTop,
        android.R.attr.layout_marginRight,
        android.R.attr.layout_marginBottom,
        android.R.attr.layout_marginStart,
        android.R.attr.layout_marginEnd,
        android.R.attr.contentDescription,
        android.R.attr.background,
        android.R.attr.foreground,
        android.R.attr.importantForAccessibility,
        android.R.attr.duplicateParentState,
      },
      /* srcPos */ 0,
      R.styleable.ComponentLayout,
      /* destPos */ 0,
      R.styleable.ComponentLayout.length);

    System.arraycopy(
      new int[]{
        android.R.attr.minLines,
        android.R.attr.maxLines,
        android.R.attr.textColor,
        android.R.attr.textColorLink,
        android.R.attr.textColorHighlight,
        android.R.attr.textSize,
        android.R.attr.lineSpacingMultiplier,
        android.R.attr.ellipsize,
        android.R.attr.textAlignment,
        android.R.attr.textStyle,
        android.R.attr.text,
        android.R.attr.textDirection,
        android.R.attr.includeFontPadding,
        android.R.attr.singleLine,
        android.R.attr.shadowColor,
        android.R.attr.shadowDx,
        android.R.attr.shadowDy,
        android.R.attr.shadowRadius,
        android.R.attr.gravity,
        android.R.attr.minEms,
        android.R.attr.minWidth,
        android.R.attr.maxEms,
        android.R.attr.maxWidth,
      },
      /* srcPos */ 0,
      R.styleable.Text,
      /* destPos */ 0,
      R.styleable.Text.length);

    System.arraycopy(
      new int[]{
        android.R.attr.src,
        android.R.attr.scaleType,
      },
      /* srcPos */ 0,
      R.styleable.Image,
      /* destPos */ 0,
      R.styleable.Image.length);

  }
}