CSC/ECE 517 Fall 2016/E1634.Refactor and write unit test of due date.rb and deadline helper.rb

Introduction

Expertiza

Expertiza is an open source project for school assignment management for instructors and students based on the Ruby on Rails framework. Expertiza allows the instructor to create new assignments and customise new or existing assignments. It also allows the instructor to create a list of topics the students can sign up for. Students can form teams in Expertiza to work on various projects and assignments. Students can also peer review other students' submissions. Expertiza supports submission across various document types, including the URLs and word documents. Expertiza provides a dashboard for all the assignments corresponding to a course and provides absolute control to the Instructors and Teaching Assistants. In addition to assignments, it encompasses peer reviews wherein participants are allowed to provide feedback anonymously about each other's work thereby providing scope for the better outcome. The due_date.rb file is responsible for informing the users about the deadline for submission of the each assignment. Due dates in Expertiza have their association with many other components like assignments, reviews etc.

Code Climate

Code Climate<ref></ref> is a tool that runs static analysis on a GitHub project and outputs many details like test coverage, complexity, duplication, security, style, and more. There is a Google Chrome extension to integrate the Code Climate results generated directly into GitHub which is visible when browsing the repository on the browser. It allows us to see issues displayed directly inside GitHub's UI, to review which lines are covered in diffs and files, and add repositories and open tickets without changing your workflow.

Tasks Identified

To install Code climate Chrome Extension that highlights the duplicated code.

To refactor the following two files:

• Due_date.rb
  • Ternary operators must not be nested. Prefer `if` or `else` constructs instead.
  • Useless assignment to variable - `sorted_deadlines`.
  • Prefer `each` over `for`.
  • Use `find_by` instead of `where.first`.
  • Correct the use of Time function
• Deadline_helper.rb
  • Do not use `Time.now` without zone. Use one of `Time.zone.now`, `Time.current`, `Time.now.in_time_zone`, `Time.now.utc`, `Time.now.getlocal`, `Time.now.iso8601`, `Time.now.jisx0301`, `Time.now.rfc3339`, `Time.now.to_i`, `Time.now.to_f` instead.
  • Trailing whitespace detected.
  • Extra empty line detected at module body end.

• Create respective RSpec files in /spec/models/ and /spec/helper folder and write unit tests for each method in due_date.rb and deadline_helper.rb.

Current Implementation

DueDate is a Model class to manage the deadlines of an assignment. It has methods for setting due dates for an assignment, copying due dates from one assignment to a new assignment etc. DeadlineHelper provides helper functions that help DueDate perform certain tasks. The assignment focuses on refactoring some of the methods based on warnings received from Code Climate's static analysis and modifying the language to make it more Ruby-friendly. The assignment also involves writing unit test cases for due_date.rb and deadline_helper.rb in order to increase test coverage.

The goal of this project is to attempt to make this part of the application easier to read and write unit test cases that the application must pass.

Changed Implementation

Changes implemented involves refactoring the code and making it more understandable by adding comments in the code.

The modified files are

• Due_date.rb (path: /app/models)

• Deadline_helper.rb (path: /app/helpers)

Testing files

• Due_date_spec.rb (path: /spec/models)
• Deadline_helper_spec.rb (path: /spec/helpers)

Due_date.rb

• Converted for..in loop to object.each in order to follow better Ruby syntax.
• Unnecessary assignment to sorted_deadlines removed.
• Nested ternary operators have been changed to if..else in order to make it more readable.

  • 

    Due_date.rb

• Changed where(...).first to find_by(...) which is the newer recommended syntax.
• Corrected the Time.now functions by adding the correct zones to them such as Time.zone.now.
• Removed trailing whitespaces.

  

Deadline_helper.rb

• Time functions were changed to functions with zones
• Extra line removed

Deadline_helper

RSpec testing

There were no existing tests for the functions in due_date.rb and deadline_helper.rb. We have added exhaustive set of RSpec tests to test all the code. We have added two new spec files 'due_date_spec.rb' and ‘deadline_helper_spec.rb’ which cover the testing scenarios for the functions in ‘due_date.rb’ and ‘deadline_helper.rb’.

These RSpec files have 100% code coverage visible at: /coverage/index.html

due_date_spec.rb

This file is located at spec/models and tests the functionalities of the due_date.rb file located in app/models. There are 18 test cases in total which are listed below.

• If the factory is successfully able to build the due_date objects.

  it "due date factory created successfully" do
      expect(@assignment_due_date).to be_valid
  end
  

  it "due dates created correctly" do
      expect(@due_dates.length).to be == 10
  end
  

• If the function "set_flag" successfully sets the due_date flag.

  it "due date flag is set" do
      expect(@assignment_due_date.flag).to be false
      @assignment_due_date.set_flag
      expect(@assignment_due_date.flag).to be true
  end
  

• If the function "due_at_is_valid_datetime" returns nil (no errors) for a valid datetime in due_at (no invalid test cases can be added here because model does not allow invalid datetime to be set at all).

  it "due at is valid datetime" do
      expect(@assignment_due_date.due_at_is_valid_datetime).to be nil
  end
  

• If the function "self.copy" is able to copy due dates from one assignment to another.

  it "copy due dates to new assignment" do
      new_assignment_id = build(:assignment, id: 999).id
      old_assignment_id = @assignment_due_date.assignment.id
      DueDate.copy(old_assignment_id, new_assignment_id)
      expect(DueDate.where(parent_id: new_assignment_id).count).to eql DueDate.where(parent_id: old_assignment_id).count
  end
  

• If the function "self.set_duedate" is able to create another due date by copying data from an existing due date object.

  it "create new duedate record with values" do
      DueDate.set_duedate({id: 999}, @assignment_due_date.deadline_type_id,
                          @assignment_due_date.parent_id, @assignment_due_date.round)
      new_due_date = DueDate.find_by(id: 999)
      expect(new_due_date).to be_valid
      expect(new_due_date.deadline_type_id).to eql @assignment_due_date.deadline_type_id
      expect(new_due_date.parent_id).to eql @assignment_due_date.parent_id
      expect(new_due_date.round).to eql @assignment_due_date.round
  end
  

• If the function "self.deadline_sort" is able to sort the due dates in ascending order.

  it "sort duedate records" do
      sorted_due_dates = @due_dates
      expect(sorted_due_dates.each_cons(2).all?{|m1, m2| (m1.due_at <=> m2.due_at) != 1}).to eql false
  
      sorted_due_dates = DueDate.deadline_sort(@due_dates)
      expect(sorted_due_dates.each_cons(2).all?{|m1, m2| (m1.due_at <=> m2.due_at) != 1}).to eql true
  end
  

• If the function "self.done_in_assignment_round" returns the correct number of rounds for specific inputs. This involves an invalid test case as well for 0 rounds.

  describe "#done_in_assignment_round" do
      it "return 0 when no response map" do
        response = ReviewResponseMap.create
        response.type = "ResponseMap"
        response.save
        expect(DueDate.done_in_assignment_round(1, response)).to eql 0
      end
  
      it "return round 1 for single round" do
        response = ReviewResponseMap.create
        expect(DueDate.done_in_assignment_round(@assignment_due_date.parent_id, response)).to eql 1
      end
  end
  

• If the function "self.get_next_due_date" works as expected. This involves several invalid test cases as well.

  describe "#get_next_due_date" do
      it "no subsequent due date" do
        expect(DueDate.get_next_due_date(@assignment_due_date.parent_id)).to be nil
      end
  
      it "nil value throws exception" do
        expect { DueDate.get_next_due_date(nil) }.to raise_exception(ActiveRecord::RecordNotFound)
      end
  
      it "get next assignment due date" do
        due_date = create(:assignment_due_date, deadline_type: @deadline_type,
          submission_allowed_id: @deadline_right.id, review_allowed_id: @deadline_right.id,
          review_of_review_allowed_id: @deadline_right.id, due_at: Time.zone.now + 5000)
        expect(DueDate.get_next_due_date(due_date.parent_id)).to be_valid
      end
  
      it "get next due date from topic for staggered deadline" do
        assignment_id = create(:assignment, staggered_deadline: true, name: "testassignment").id
        due_date = create(:topic_due_date, deadline_type: @deadline_type,
          submission_allowed_id: @deadline_right.id, review_allowed_id: @deadline_right.id,
          review_of_review_allowed_id: @deadline_right.id, due_at: Time.zone.now + 5000, parent_id: assignment_id)
        expect(DueDate.get_next_due_date(assignment_id, due_date.parent_id)).to be_valid
      end
  
      it "next due date does not exist for staggered deadline" do
        assignment_id = create(:assignment, staggered_deadline: true, name: "testassignment").id
        due_date = create(:topic_due_date, deadline_type: @deadline_type,
          submission_allowed_id: @deadline_right, review_allowed_id: @deadline_right,
          review_of_review_allowed_id: @deadline_right, due_at: Time.zone.now + 5000, parent_id: assignment_id)
        expect(DueDate.get_next_due_date(assignment_id)).to be nil
      end
  
      it "next due date is before Time.now for staggered deadline" do
        assignment_id = create(:assignment, staggered_deadline: true, name: "testassignment").id
        due_date = create(:topic_due_date, deadline_type: @deadline_type,
          submission_allowed_id: @deadline_right, review_allowed_id: @deadline_right,
          review_of_review_allowed_id: @deadline_right, due_at: Time.zone.now - 5000, parent_id: assignment_id)
        expect(DueDate.get_next_due_date(assignment_id, due_date.parent_id)).to be nil
      end
  
      it "get next due date from assignment for staggered deadline" do
        assignment_id = create(:assignment, staggered_deadline: true, name: "testassignment").id
        due_date = create(:assignment_due_date, deadline_type: @deadline_type,
          submission_allowed_id: @deadline_right, review_allowed_id: @deadline_right,
          review_of_review_allowed_id: @deadline_right, due_at: Time.zone.now + 5000, parent_id: assignment_id)
        expect(DueDate.get_next_due_date(assignment_id)).to be_valid
      end
  end
  

• If the function "self.default_permission" returns the correct default permissions for particular deadline and permission types.

  it "metareview review_of_review_allowed default permission OK" do
      expect(DueDate.default_permission('metareview', 'review_of_review_allowed')).to be == DeadlineRight::OK
  end
  

  it "review submission_allowed default permission NO" do
      expect(DueDate.default_permission('review', 'submission_allowed')).to be == DeadlineRight::NO
  end
  

To test this file run the following command:

rspec spec/models/due_date_spec.rb

The output of this RSpec file is present in below screenshot:

Code coverage details of the above RSpec files is present in below screenshot:

Code coverage details of the above RSpec files is present in below screenshot:

deadline_helper_spec.rb

This is a test file for testing the functionalities of Deadline_helper.rb file located at app/helpers. Different test cases present in this file are:

• Check if the factory is valid:

it "has a valid factory" do
    factory = FactoryGirl.build(:topic_due_date)
    expect(factory).to be_valid
end

• Fail if the due date is invalid:

it "should fail because of invalid due_date" do
      expect { DeadlineHelper.create_topic_deadline(nil, 0, 0)}.to raise_exception(NoMethodError)
end

• If new due_date object is created:

  it "new due_date object created" do
        DeadlineHelper.create_topic_deadline(@topic_due_date, 0, 1)
        expect(TopicDueDate.count).to be == 2
  end
  

• due_at should be same for 0 offset:

   it "due_at should be same for 0 offset" do
        DeadlineHelper.create_topic_deadline(@topic_due_date, 0, 10)
        new_due_date = TopicDueDate.find_by(parent_id: 10)
        expect(new_due_date).to be_valid
        expect(new_due_date.due_at.to_s).to be == @topic_due_date.due_at.to_s
  end
  

• due_at is calculated correctly if offset is positive:

  it "due_at calculated correctly for positive offset" do
        DeadlineHelper.create_topic_deadline(@topic_due_date, 5000, 10)
        new_due_date = TopicDueDate.find_by(parent_id: 10)
        expect(new_due_date).to be_valid
        expect(new_due_date.due_at.to_s).to be == (Time.zone.parse(@topic_due_date.due_at.to_s) + 5000).to_s
  end
  

• due_at is calculated correctly if offset is negative:

  it "due_at calculated correctly for negative offset" do
        DeadlineHelper.create_topic_deadline(@topic_due_date, -5000, 10)
        new_due_date = TopicDueDate.find_by(parent_id: 10)
        expect(new_due_date).to be_valid
        expect(new_due_date.due_at.to_s).to be == (Time.zone.parse(@topic_due_date.due_at.to_s) - 5000).to_s
  end
  

• The offset is being converted to integer properly:

  it "offset converted to integer correctly" do
        DeadlineHelper.create_topic_deadline(@topic_due_date, 5000.15, 10)
        new_due_date = TopicDueDate.find_by(parent_id: 10)
        expect(new_due_date).to be_valid
        expect(new_due_date.due_at.to_s).to be == (Time.zone.parse(@topic_due_date.due_at.to_s) + 5000).to_s
  end
  

To test this file run the following command:

rspec spec/models/deadline_helper_spec.rb

The output of this RSpec file is present in below screenshot:

Code coverage details of the above RSpec files is present in below screenshot: