Bingo for meetings–obsolete–part 6

Bingo

Bingo is a small project, written in TypeScript , and developed with Alexandru Badita in launch break (one hour - more or less). You can find sources at https://github.com/alexandru360/PresentationBingoCards/ . Those are my blog posts for Bingo : ( scroll below for the post)

Nr	Link
1	Create meeting
2	Create Tests
3	Finalize Create meeting
4	Sharing meeting
5	Keep Score
6	Add obsolete
7	Finalizing obsolete
8	End meeting
9	Dockerize tests
10	Azure CI tests
11	Yarn workspaces
12	CLI
13	Intermezzo - CLI improvements
14	typescript compile run with node
15	NestJS ,swagger and create a meeting
16	Finalizing API
17	Intermezzo - jest vs jasmine error
18	Refactor WebAPI and test service
19	Heroku Deploy NestJs
20	Angular
21	Deploy Angular to GitHub
22	WebAPI and Web
23	Documentation
24	Documentation of the code
25	Conclusions

The requirement says:

Meeting Obsolete:
The meeting is available for 35 minutes. After that, meeting is not available anymore.

How we can implement this ? Several solutions:

1. Make the meeting know about this ( and avoiding https://martinfowler.com/bliki/AnemicDomainModel.html )
2. Make a decorator class for this https://en.wikipedia.org/wiki/Decorator_pattern
3. Make a mixin in TypeScript https://www.typescriptlang.org/docs/handbook/mixins.html

 

I decide to KISS (https://en.wikipedia.org/wiki/KISS_principle ) and take the first point. We implement an Obsolete function. Remains who is responsible of the site to call it.

Now comes other question: When the meeting starts  ?I consider ( for the sake of easy path) that a meeting starts when it is created . So the code is like this

export default class Meeting{

    constructor(){
        this.Participants = [];        
        this.Cards = [];
        this.startedMeeting = Date.now();
    }
    public static  MaxTime=35 * 60 * 1000;
    // other code here
    public IsObsolete(): boolean{
        return (this.PassedTimeFromStart() > Meeting.MaxTime); //35 minutes
    }
    public PassedTimeFromStart():number{
        let dtNow =  Date.now();
        console.log(dtNow);
        return (dtNow - this.startedMeeting );
    }

 

 

Now the problem arises when testing code. It is very easy to say that a meeting is not obsolete when just created. However , I do not want to wait for 35minutes + 1 second in order for a meeting to become obsolete and the test to be successful( see
//TODO: wait 35 minutes + 1 second

below).

import  MeetingsFactory from '../MeetingsFactory';
import Meeting from '../meeting';
describe('Meeting Obsolete', () => {
    it('meeting should not be obsolete after creation', () => {
        const mf=new MeetingsFactory();
        const m1=mf.CreateMeeting("andrei","first meeting");
        expect(m1.IsObsolete()).toBe(false);
        
        
  
      })
      it('meeting should  be obsolete after 35 minutes', () => {
        const mf=new MeetingsFactory();

        const m1=mf.CreateMeeting("andrei","first meeting");
        //TODO: wait 35 minutes + 1 second
        expect(m1.IsObsolete()).toBe(true);
        
  
      })
  })
  

One possible resolution is https://ayende.com/blog/3408/dealing-with-time-in-tests . However, the problem is so common that here must be include in the test framework ( in this case, jest). And , indeed, it is a way: spyon. So the code is modified accordingly :

it('meeting should  be obsolete after 35 minutes', () => {
        const mf=new MeetingsFactory();

        const m1=mf.CreateMeeting("andrei","first meeting");
        const now = Date.now();
        const spy = jest.spyOn(Date,'now');
        spy.mockImplementation(()=>{
          console.log('calling DateTime Now');
          return now + 36 * 60* 1000;
        } );
        expect(m1.IsObsolete()).toBe(true);
        //spy.mockClear();        
        spy.mockRestore();
        expect(m1.IsObsolete()).toBe(false);
        
  
      })

The testing code now assumes that he knows inner working of the code – and the test will fail if we modify the call of Date.now().
So I think that https://ayende.com/blog/3408/dealing-with-time-in-tests is far superior.