packages/dubbo/src/__tests__/async-test.ts

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
async function hello() {
  return {err: null, res: 'hello'};
}

async function world() {
  return {err: null, res: 'world'};
}

async function temp() {
  return {err: new Error('I am error'), res: null};
}

class AsyncWrapper {
  public error: Error;

  private constructor() {
    this.error = null;
  }

  static create() {
    return new AsyncWrapper();
  }

  async go(fn) {
    if (this.error) {
      return null;
    }

    const {err, res} = await fn();

    if (err) {
      this.error = err;
      return null;
    }

    return {err, res};
  }

  get err() {
    return this.error;
  }
}

it('test async', async () => {
  const aw = AsyncWrapper.create();
  const res = await aw.go(hello);
  expect(res).toEqual({err: null, res: 'hello'});

  const res1 = await aw.go(temp);
  expect(res1).toEqual(null);

  const res2 = await aw.go(world);
  expect(res2).toEqual(null);

  if (aw.error) {
    expect(aw.error.message).toEqual('I am error');
  }
});