tools/winscope/src/common/function_utils.ts

/*
 * Copyright (C) 2022 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Type of the onProgressUpdate callback function.
 */
export type OnProgressUpdateType = (percentage: number) => void;

/**
 * A function that does nothing.
 */
export const DO_NOTHING = () => {
  // do nothing
};

/**
 * A function that does nothing asynchronously.
 */
export const DO_NOTHING_ASYNC = (): Promise<void> => {
  return Promise.resolve();
};

/**
 * Mixin two objects together.
 *
 * This function takes two objects and returns a new object that is the
 * result of merging the two objects. The properties of the first object
 * take precedence over the properties of the second object if there are
 * any conflicts.
 *
 * @param a The first object.
 * @param b The second object.
 * @return The merged object.
 */
export function mixin<T extends object, U extends object>(a: T, b: U): T & U {
  const ret = {};
  Object.assign(ret, a);
  Object.assign(ret, b);

  const assignMethods = (dst: object, src: object) => {
    for (const methodName of Object.getOwnPropertyNames(
      Object.getPrototypeOf(src),
    )) {
      const method = (src as any)[methodName];
      (dst as any)[methodName] = method;
    }
  };

  assignMethods(ret, a);
  assignMethods(ret, b);

  return ret as T & U;
}