js-cqrs

Usage

js-cqrs is a lightweight and easy to use implementation of the cqrs pattern. It allows for quick integration due to simplified API.

export class SaveUserRequest extends Command{
    data: any;
    constructor(data: any){
            this.data = data;
    }
}

export class SaveUserRequestHandler extends CommandHandler {
    handle(command: SaveUserRequest){
            var event = new UserSaved({firstName: command.data.firstName});
            Cqrs.Instance.Publish(event);
    }
}

export class UserSaved extends Event {
    data: any;
    constructor(data: any) {
        this.data = data;
    }
}

class EventListener1 extends EventListener {
    static processed: boolean = false;
    static firstName: string = "";
    handle(event: UserSaved) {
        EventListener1.processed = true;
        EventListener1.firstName = event.data.firstName;
    }
}

class EventListener2 extends EventListener {
    static processed: boolean = false;
    handle(event: UserSaved): void {
        EventListener2.processed = true;
    }
}

Cqrs.Instance.AddCommandHandler(SaveUserRequest, SaveUserRequestHandler, null);
Cqrs.Instance.AddEventListener(UserSaved, EventListener1, null);
Cqrs.Instance.AddEventListener(UserSaved, EventListener2, null);

let newSaveUserCommand = new SaveUserRequest({ id: '1', firstName: 'Sebastian' });
Cqrs.Instance.Send(newSaveUserCommand);

expect(EventListener1.processed).toBe(true);
expect(EventListener2.processed).toBe(true);
expect(EventListener1.firstName).toBe("Sebastian");