The purpose of this exercise is to train basic inheritance features.

Estimated workload of this exercise is 120 min.

In this exercise we are going to manage business logic of planning a sprint. A sprint is the basic unit of software development in SCRUM. Sprints are timeboxed. Time capacity of a sprint is agreed while planning. Then we consdier a sprint to be filled with some tasks.

We consider a task to be implemented with general-purpose Ticket class. But we also consider a sprint to accept only subtypes of the Ticket class: Bug and UserStory.

Here is a diagram depicting the public interface of these classes and their relations:

Here are API details:

• Ticket
  Every ticket has an id, a name and an estimate of hours to complete it. One provides them via the constructor of the Ticket class. Also, a ticket may be completed or not. When a ticket is created, it is not completed.
  • getId() - Returns the id of the ticket.
  • getName() - Returns the name of the ticket.
  • getEstimate() - Returns the estimate of the ticket.
  • isCompleted() - Returns true if the ticket is completed, false otherwise.
  • complete() - Sets the ticket to completed state.
• UserStory
  We consider a user story to be a ticket that may contain some dependencies. A dependency is another user story that must be completed first to allow the dependent user story to complete. One provides dependencies of the UserStory via the constructor of the UserStory class.
  • complete() - Like the Ticket#complete() method, this sets the ticket to completed state. The difference is that the user story may not be completed if its dependencies are not completed yet.
  • getDependencies() - Returns a defensive copy of dependencies array.
  • toString() - Returns a String representing this user story, using its id and name. Example: "[US 1] User Registration Entity"
• Bug
  We consider a bug to be a ticket, that is related to some completed user story. Bugs may not exists by their on, without a related user story.
  • createBug(int id, String name, int estimate, UserStory userStory) - A static method to create a Bug instance.
    Returns null if the related user story is null or is not completed. Otherwise, returns a created Bug instance.
  • toString() - Returns a String representing this bug, using its id, name and the name of the related user story.
    Example: with id = 2, name = "Add password repeat" and the related user story name = "Registration Form" the resulting string would be "[Bug 2] Registration Form: Add password repeat"
• Sprint
  Sprints has the time capacity and the tickets limit, specified via constructor. It is not allowed for a Sprint to contain tickets with total estimate greater than time capacity. It is not allowed for a Sprint to contain total amount of tickets greater than tickets limit.
  We consider a sprint to accept tickets via add* methods. That methods return true when an input ticket was accepted and false otherwise. Note that we consider a sprint to not accept:
  1. null values,
  2. tickets, that are already completed
  3. tickets, that has an estimate value that will lead to capacity overflow if added
  4. any ticket, if the sprint ticket limit is reached.
  • addUserStory(UserStory userStory) - accepts a userStory, if it is not null, not completed and its uncompleted dependencies are already accepted to the sprint. Returns true if the user story is accepted, false otherwise.
  • addBug(Bug bugReport) - accepts a bug, if it is not null and not completed. Returns true if the bug is accepted, false otherwise.
  • getTickets() - Returns a defensive copy of the array of the sprint tickets. Make sure the order of tickets is as they were accepted to the sprint.
  • getTotalEstimate() - Returns the sum of estimates of all the tickets accepted to the sprint.

Important restriction: Note that in this exercise you may not use Collections and Streams.

See usage examples in tests inside src/test/java.

Wikipedia on the Scrum Sprint: https://en.wikipedia.org/wiki/Scrum_(software_development)#Sprint