如何测试 promise 中调用的方法

Question

I have a function that saves an entity and in the promise i want to check the delete is called.

In my jest test it whizzes past and can't think how to test it

Here is the partial snippets, it all works, Promises called etc. just can't figure how to test that 'deleteMessage' is called

              this.service
              .save(entity)
              .then(() => {
                this.sqsQueue.deleteMessage(message.ReceiptHandle!);
              })
              .catch((error) => {
                this.log.error('Error saving');
              });

In my test i use

service.save = jest.fn().mockResolvedValue(null);
expect(sqsQueue.deleteMessage).toHaveBeenNthCalledWith(
      1,
      deleteItem1.ReceiptHandle
    );

As mentioned because it's a Promise, the test doesn't wait for the save and and runs the expect which of course fails because the function has not run yet.

Answer 1

test('item is deleted', () => {
  return service.save().then(() => {
   // Put your expects here
   });
});

For more info see the docs: https://jestjs.io/docs/en/asynchronous