CSC/ECE 517 Spring 2015/oss E1503 RSA

E1503. Refactor Leaderboard model, Leaderboard_helper and LeaderboardController classes

This page provides a description of the Expertiza based OSS project. This project aimed at refactoring the Leaderboard model, LeaderboardController, and Leaderboard_helper classes as per standard coding methodology for Ruby on Rails.

Introduction to Expertiza

Expertiza is a peer review based system used to provide improved learning experience. Project is developed as a combined effort of students and faculty using the Ruby on Rails framework. Expertiza allows the instructor to create and customize assignments, create a list of topics the students can sign up for, have students work on teams and then review each other's assignments at the end. Expertiza supports submission of almost any document type, including the URLs and wiki pages.

Leaderboard is a module that can be used to find top three leaders in any class based on the score they have received on their submissions and reviews.

Project Description

Classes involved:

leaderboard.rb
leaderboard_controller.rb

Modules involved:

leaderboard_helper.rb

What they do

These class are responsible for calculating top 3 individuals which is to be displayed as the leaderboard for the class and generate a metric which aggregates peer review scores for all course assignments and then sorts individuals.

What needs to be done

Methods like getParticipantsScore and extractPersonalAchievements needs to be refactored as these single functions have multiple responsibilities. They can be modularized delegating single resposibility to single function. sortHash method is not an explicit leaderboard model and can be moved to helper functions. Some snippets of code are redundant and have no effect on functionality. They can be removed.

Changes Made

Leaderboard model was having public methods containing more than one feature in each method. We refactored such public methods in necessary public and private methods. Since we didn't create any new public method, we used the existing test cases to validate the changes. We removed helper methods from model class to respective helper class and changed all the references in model and controller classes.

Leaderboard Model

Method Name	Changes Made	Reason For Change
model/Leaderboard#getParticipantsScore	Refactored original method functionality into getAssignmentUniqueParticipantList, getAssignmentUniqueParticipantTeamList, getAggregatedAssignmentRevieweeList, getRevieweeListScore, and getUserScoreHashForCourse methods	Many different features were originally written in one method. We refactored this method into many methods to achieve singularity.
model/Leaderboard#sortHash helpers/leaderboard_helper#sortHash	Migrated method from Leaderboard model to leaderboard_helper class.	sortHash is a helper method and is not explicit part of model class, hence it was moved to achieve code reusability and remove redundancy.
model/Leaderboard scoreEntryScore parameter	Parameter name is changed to entryScore	The name was confusing. It was used to represent each entry's score, hence we changed the name to maintain readability of code.
model/Leaderboard#extractPersonalAchievements	Removed unwanted code snippets	Redundant code snippet was found which has no affect on program.
model/Leaderboard#extractPersonalAchievements	Refactored method functionality and created private method, getCourseAccomplishmentHash	More than one feature was implemented into one method. we split the functionality and remove code redundancy.

Leaderboard Controller

Method Name	Changes Made	Reason For Change
index	Updated reference to sortHash method	We moved sortHash method from model class to helper class. We updated all the old references for this method in index method on mentioned controller.

Re-factored Code Cases

Case 1 : Refactoring ...

Functions added

  # This method returns the unique participants for assignment list.
  def self.getAssignmentUniqueParticipantList(assignmentList)
    AssignmentParticipant.where(:parent_id => assignmentList.pluck(:id)).uniq
  end

  # This method returns the unique participant teams for assignment list.
  def self.getAssignmentUniqueParticipantTeamList(assignmentList)
    Team.where("parent_id IN (?) AND type = ?", assignmentList.pluck(:id), 'AssignmentTeam').uniq
  end

Before Refactoring

assignmentMap = getAssignmentMapping(assignmentList, participantList, teamList)

After Refactoring

assignmentMap = getAssignmentMapping(assignmentList, getAssignmentUniqueParticipantList(assignmentList), getAssignmentUniqueParticipantTeamList(assignmentList))

Automated Tests

Unit test

We didn't create any new public method as part of this project, instead we refactored the existing code. Existing test suit was suitable for testing our modifications.