CSC/ECE 517 Spring 2020/E2012. refactor lottery controller.rb

Introduction

Expertiza Background

Expertiza is an open-source project written using the Ruby on Rails framework. The Expertiza platform aims to improve student learning by using active and cooperative learning, allowing distance education students to participate in active learning, and by discouraging plagiarism through the use of multiple deadlines. Expertiza helps to improve teaching and resource utilization by having students contribute to the creation of course materials and through peer-graded assignments. Expertiza manages objects related to a course such as instructors, TAs, students, and other users. It also manages assignments, teams, signup topics, rubrics, peer grading, and peer evaluations.

Lottery Controller Background

An assignment can have a list of signup topics. The teams associated with the assignment can bid on the signup topics to try and get assigned one they find more favorable. At a high level, the lottery controller assigns teams to topics based on the priorities the team gave to each signup topic during the bidding process.

In more detail, each student starts off on a team of size 1. They can bid on signup topics by arranging them in priority order. A team can invite other users to join their team. If student2 from Team B joins Team A which includes student1, student2 will lose their bids and take on the bids of TeamA and student1. When the lottery controller is called to run its method run_intelligent_assignment, a web service takes the bidding data from each team and returns a new list of teams, each of which is closer to the maximum team size specified for the assignment. The web service combines teams together that have similar bid data and then assigns those new teams to topics, giving each team their top bid on a topic that hasn't been assigned yet. Teams with larger team sizes and more bids are assigned their topics first.

Problem Statement

Code Climate currently grades `lottery_controller.rb` at a C level, finding issues with the controller's long methods and complex statements. Most methods are around 40 lines and hard to decipher with a quick look. Also, the file currently has only 10% test coverage. Our goal is to resolve the Code Climate issues, make methods simpler to understand and write new tests to improve test coverage.

Tasks Identified

• 1. Cut down on code in run_intelligent_assignment method by moving some code to helper methods
• 2. Cut down on code in create_new_teams_for_bidding_response by moving some code to helper methods
• 3. Cut down on code in match_new_teams_to_topics by moving some code to helper methods
• 4. Reduce cognitive complexity of merge_bids_from_different_previous_teams method
• 5. Add additional comments to clarify newly written methods
• 6. Add additional RSpec tests to increase the coverage percentage