超过 10000 毫秒的摩卡单元测试超时使用 await Promise.all 时出错

Question

File: index.ts // Class Based Default exported

getItemsA() {
  return Promise.resolve({ // Api Call in real scenario. Mocking here for now.
    success: true;
    result: [{
     itemA: []
    }]
  });
}

getItemsB() {
  return Promise.resolve({ // Api Call in real scenario. Mocking here for now.
    success: true;
    result: [{
     itemB: []
    }]
  });
}

File service.ts

import { getItemsA, getItemsB } from 'index.ts';

getService() {
  return new Promise(async (resolve, reject) => {
    const parallelApis = await Promise.all([  // UT Stucks here. Not able to get the parallelApis response.
      getItemsA(), getItemsB()
    ]);

   .... other mapping

   resolve({
      .......
   });
  });
}

File test.ts

import items from 'index.ts'; // Class based. Default exported
import service from 'service.ts'; // Class based. Default exported
import { expect } from "chai";
import * as sinon from "sinon";

describe.only("Service", () => {
   let itemAStub;
   let itemBStub;

   beforeEach(() => {
     itemAStub = sinon.stub(items, "getItemsA");
     itemBStub = sinon.stub(items, "getItemsB");

     itemAStub.callsFake(() => {
        return Promise.resolve({
            body: myMock // Dummy
        });
     });

   itemBStub.callsFake(() => {
        return Promise.resolve({
            body: someOtherMock // Dummy
        });
     });
   });

   afterEach(() => {
        itemAStub.restore();
        itemBStub.restore();
   });

   it("Should filter valid gift options", (done) => {
      service.getService().then(res => {
                console.log("RESPONSEEEEEE", res);
                expect(res).to.deep.equal(myMockResponse);
                done();
            })
            .catch(err => {
                console.log("Errorr");
                done(err);
            });
   });
});

Can somebody help me to identify the issue when i tried to run the test case I am getting the below error.

Error: Timeout of 10000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.

I know that extending the timeout is not a solution to fix the issue. Stub is created, but not sure why it is getting timeout error when code reaches await Promise.all. If I remove done() then test case will succeed but then function is not getting executed. Any help would be really appreciated.

Answer 1

The promise returned by getService isn't being resolved in the code posted so would remain pending and hit the time limit.

Since you've used an async function as the executor in the call to new Promise , it is possible you don't need to create a new promise at all - depending on what the code does you could try something like

getService() {
    return Promise.all([
      getItemsA(), getItemsB()
    ]);
  });
}

This doesn't clear up what "other mapping" means, but keep in mind that an async function returns a promise that is resolved by the apparent return value of the function body, or rejected by an error thrown in the async function's body code.And you could make getService an async function if need be.

Answer 2

When we run Mocha from the command line, it will read this file which has a default timeout.

To change this time you can reset using:

./node_modules/.bin/mocha  --timeout 20000