CSC/ECE 517 Fall 2019 - E1942. Refactor stage deadlines in assignment.rb

Expertiza Background

Expertiza is an assignment portal developed by faculties and students at NCSU. It provides a platform for the faculties to create assignments for students. Faculties can have assignments with staged deadlines. Expertiza has support to create teams for students, track the team members and provide review for the work done by team members. Students can also provide reviews for peer team's assignment submission. Expertiza has been developed on Ruby on Rails and is available on github.

Problem Description

Following is an OSS project which deals with refactoring of stage deadlines in assignment.rb file. An assignment can have incremental deadlines for different topics in a single assignment. This project involves refactoring the functions in assignment.rb file related to stage deadlines. There were five functions to check what kind of stage an assignment is in. However, the names of these functions were ambiguous and functionalities implemented in some of them overlapped with each other. By the end of this project we have refactored these deadline functions.

Current Scenario

The assignment.rb file has the following functions implemented :
1. current_stage_name(topic_id = nil)
2. find_current_stage(topic_id = nil)
3. get_current_stage(topic_id = nil)
4. link_for_current_stage(topic_id = nil)
5. stage_deadline(topic_id = nil)

We have found the following issues with the code with respect to Ruby conventions :

Multiple calls to DueDate.get_next_due_date()

Problem with Existing code:
In the existing code, DueDate.get_next_due_date(self.id, topic_id) has been called at numerous places. This does not follow the ruby coding standards.

Solution:
New private method next_due_date(topic_id) has been added. This function returns the next_due_date by calling the get_next_due_date method on DueDate.

File: app/models/assignment.rb
Code:

def next_due_date(topic_id = nil)
 DueDate.get_next_due_date(self.id, topic_id)
end

Following places have been refactored.

Screenshots.

Checking finished status with static string “Finished”

Problem with Existing code:
The above methods have been used at various places to check finish status of assignment by comparing with “Finished”. This does not follow ruby coding standards, as we should never compare with static things. Otherwise it becomes difficult to refactor the code later.

Solution:
Assignment is said to be finished if the next due is nil. A new private method finished? has been added. It calls the above next_due_date method and returns true if the next_due_date is nil.

File: app/models/assignment.rb Code:

def finished?( topic_id = nil )
 next_due_date(topic_id).nil?
end

The check with “Finished” has been replaces with a call to finished? . The code has been refactored at following places.

Screenshots.