CSC/ECE 517 Fall 2021 - E2121. Refactor suggestion controller.rb

This page provides a description of the Expertiza based OSS project.

About Expertiza

Expertiza is an open source project based on Ruby on Rails framework. Expertiza allows the instructor to create new assignments and customize 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 wiki pages.

Problem Statement

The following tasks were accomplished in this project:

Used more Ruby-like String concepts.
Refactor create_new_team to assignment_team.rb.
Refactor notification to simplify control logic.
Refactor approve_suggestion to indicate that notification is being sent.
Added RSPEC testcases for testing changes done in Suggestion Controller.

About Suggestion Controller

TBD

Problems and Solutions

Problem 1: The method paginate_list is doing more than one thing.

The method paginate_list was building a complex search criteria based on the input params, getting the list of versions from the Database matching this search criteria and then calling the Page API. All these tasks in a single method made it difficult to understand.

# This is the code area.

Solution: The implementation has been changed in such a way that the versions which a user is allowed to see depends on the privileges of the user. The approach we have taken is as follows:
- An administrator can see all the versions
- An instructor can see all the versions created by him and other users who are in his course or are participants in the assignments he creates.
- A TA can see all the versions created by him and other users who are in the course for which he/ she assists.
- A Student can see all the versions created by him/ her.

Problem 2: The search criteria created in the method paginate_list was difficult to comprehend.

The code which builds the search criteria in the method paginate_list uses many string literals and conditions and is hardly intuitive. The programmer will have to spend some time to understand what the code is really doing.

# This is the code area.

Solution: The implementation has been changed. A student is not allowed to delete any versions now. Other types of users, for instance administrators, instructors and TAs are allowed to delete only the versions they are authorized to view.

Problem 3: The paginate method can be moved to a helper class.

VersionsController is not the only component which require to paginate items. There are other components too. For instance, the UsersController has to paginate the list of users. Hence the Paginate method can be moved to a helper class which can be accessed by other components as well.

# This is the code area.

Solution: The filtering options has also been enhanced. The current user can now choose as part of the version search filter any user from a list of users if the current user is authorized to see the versions created by that user.

Automated Testing using RSPEC

The current version of expertiza did not have any test for VersionsController. Using the test driven development(TDD) approach, we have added an exhaustive set of RSPEC tests for VersionsController, to test all the modifications we have done to the code of the controller class. The tests use double and stub features of rspec-rails gem, to fake the log in by different users - Administrator, Instructor, Student etc. The tests can be executed "rpec spec" command as shown below.

user-expertiza $rspec spec
.
.
.
Finished in 5.39 seconds (files took 25.33 seconds to load)
66 examples, 0 failures

Randomized with seed 19254
.
.

Testing from UI

Following are a few testcases with respectto our code changes that can be tried from UI: 1. To go to versions index page, type in the following url after logging in:

  http://152.46.16.81:3000/versions

2. After logging in as student/instructor or admin : Try accessing the new, create, edit, update actions. These actions are not allowed to any of the users.

  http://152.46.16.81:3000/versions/new
  This calls the new action. In the current production version of expertiza, it is unhandled and application gives a default 404 page.

3. Another feature that can be tested from UI is Pagination. Try searching for a user's versions and see if the results are paginated or not. Search here:

  http://152.46.16.81:3000/versions/search

4. Visit the same URL as step 3, you should see only the students under that instructor in the users dropdown.

References

Expertiza on GitHub
GitHub Project Repository Fork
The live Expertiza website
VCL link (will expire in 3 weeks)
Expertiza project documentation wiki
Rspec Documentation
Clean Code: A handbook of agile software craftsmanship. Author: Robert C Martin