CSC/ECE 517 Spring 2013/OSS E608

Write-up of This Topic.

E608. Refactoring and Testing - Course Related Classes

Classes Involved:

• models/course.rb (76 lines)
• models/course_participant.rb (94 lines)
• models/course_team.rb (116 lines)
• models/course_node.rb (95 lines)

What it does: Involves creation and management of courses in Expertiza

What needs to be done:

• It is not clear what a method named 'create_node' is doing in the 'course' class. Refactor by renaming this method appropriately.
• In the course_team class the import method seems to be doing too many things. See if this method can be broken down into smaller methods with specific functionality.
• The 'get' method in course_node.rb appears to be doing a lot. Refactor this method by breaking it up into smaller methods.
• Look for any unused methods or variables in these files.
• Also apply other refactorings such as Rename variable, Rename method to give the variables and methods more meaningful names.
• Write unit tests for all the methods in each of the listed model classes.

Changes for models/course.rb

The following changes were made:

• Since the method create_node simply creates a course node associated with the newly created or copied course, we replaced its functionality by adding the line CourseNode.create(:node_object_id => course.id) in the course_controller's create method and copy method. The function of getting the CourseNode's parent id is extracted as a class method of CourseNode model, since this parent id is independent of the course. With all of its functionalities refactored to other places, this method is hereby removed.
• Added the line "has_many :assigments, :dependent => :destroy" to allow CourseTest.test_destroy unit test to pass.

Changes for models/course_participant.rb

• CourseParticipant.get_parent_name is removed
  • This method is never called in the project, plus method CourseParticipant.get_course_string provides the same functionality as CourseParticipant.get_parent_name. So we deleted this method following the principle of DRY.

Changes for models/course_node.rb

• models/course_node.rb
  • The "get" method was improved.
    • Added "get_courses_managed_by_user" method to hold logic extracted from the "get"method.
    • Added "get_course_query_conditions" method to hold logic extracted from the "get" method.
    • Modified any checks on if the user is a teaching assistant to use polymorphism to make the determination.
    • Removed the initial conditional for setting the "conditions" value since the remaining conditions was overwriting the value regardless of how the initial conditional was evaluated.
    • Renaming the "get" method was considered; however, the name of the method is necessary for polymorphism reasons related to Assignment nodes. As such, a comment was added to explain why the method name should remain.
    • The "sortorder" parameter is given a default value of "ASC" for ascending. This allowed for a related conditional to be removed from the method.
    • The "sortvar" parameter is given a default value of "name" for sorting by course name. This allowed for a related conditional to be removed from the method.
  • Renaming the "get_children" method was considered; however, the name of the method is necessary for polymorphism reasons related to Assignment Nodes. As such, a comment was added to explain why the method name should remain.
  • The "get_survey_distribution_id" method was removed after finding it to be dead code.
• models/ta.rb
  • Added "is_teaching_assistant?" method to override the inherited method from the User model. This supported usage of polymorphism to determine if the user is a teaching assistant.
• models/user.rb
  • Added "is_teaching_assistant?" method to enable usage of polymorphism to determine if the user is a teaching assistant.

Methods Found That Are Not Currently Being Used

The following methods were not found to be used currently by the project, but have been left in the code for potential future usages of the functionality:

• models/course.rb
  • Course.get_participant(user_id)
• models/course_participant.rb
  • CourseParticipant.copy(assignment_id)
  • CourseParticipant.get_parent_name
• models/course_node.rb
  • CourseNode.get_modified_date

List of New Unit Tests and Testcases

The following lists shows new unit files and/or new testcases:

• test/unit/course_node_test.rb (new test file)
  • test_get_children_with_show_true_and_non_TA_and_ascending_order_by_name
  • test_get_children_with_show_true_and_non_TA_and_descending_order_by_name
  • test_get_children_with_show_true_and_TA_and_ascending_order_by_name
  • test_get_children_with_show_true_and_TA_and_descending_order_by_name
  • test_get_children_with_show_false_and_non_TA_and_ascending_order_by_name
  • test_get_children_with_show_false_and_non_TA_and_descending_order_by_name
  • test_get_children_with_show_false_and_TA_and_ascending_order_by_name
  • test_get_children_with_show_false_and_TA_and_descending_order_by_name
  • test_get_children_with_show_false_and_non_TA_and_nil_order_by_nil
  • test_get_name
  • test_get_directory
  • test_get_creation_date
  • test_get_modified_date
  • test_get_teams
  • test_get_parent_id
• test/unit/course_test.rb (previously existing test file)
  • test_get_teams
  • test_get_path
  • test_get_participants
  • test_get_participant
  • test_add_participant
  • test_copy_participants
• test/unit/course_participant_test.rb (previously existing test file)
  • test_get_course_string
  • test_import
  • test_get_path
  • test_export
  • test_get_export_field

List of Modified Unit Tests

The following unit test files and/or testcases were modified:

• test/unit/course_test.rb
  • The line "fixtures :courses" was changed to "fixtures :courses,:teams,:users,:participants,:assignments,:nodes,:tree_folders".