Legacy Associations and Validations

Description

Take an existing legacy codebase with no associations or validations and add them.

Objectives

After completing this assignment, you should...

• Become more comfortable working with code which you did not write
• Become more comfortable adding functionality to an existing codebase
• Understand how two developers can work on the same codebase
• Be able to branch your code
• Be able to handle merge conflicts
• Be able to write associations
• Be able to write validations
• Be able to add tests to verify associations and validations

Deliverables

• A GitHub organization. Your team should create a new organization in GitHub for this assignment.
• A pull request to this repository. Fork this repository to your organization, do the work, then create a pull request.
• A modified README.
• A test suite. This test suite must be written using TDD.

This means that BEFORE adding any of these validations or associations you must:

• Write a new test.
• Run your tests and see that ONLY the new one fails (but make sure that it DOES fail).
• Write code to make the test pass.
• Run your tests and see that all tests pass.
• (Repeat those last two as necessary.)

Use the homework submission form on the course website to state when you are done.

Normal Mode

Your assignment is to take the existing code in this folder and add associations and validations to it. You will be working with a partner, but you will be branching your code, splitting the tasks amongst the two of you, and working on them separately. Once you have finished your separate tasks, then you will merge your branches together and deal with any merge conflicts that arise.

If you would like, you can merge your branches more than once.

The tasks will be divided as follows. "Associate" means to place has_many, belongs_to, has_and_belongs_to_many, etc in the appropriate classes. "Validate" means to use validates in the appropriate classes with the appropriate parameters.

Person A:

• Associate schools with terms (both directions).
• Associate terms with courses (both directions). If a term has any courses associated with it, the term should not be deletable.
• Associate courses with course_students (both directions). If the course has any students associated with it, the course should not be deletable.
• Associate assignments with courses (both directions). When a course is destroyed, its assignments should be automatically destroyed.
• Associate lessons with their pre_class_assignments (both directions).
• Set up a School to have many courses through the school's terms.
• Validate that Lessons have names.
• Validate that Readings must have an order_number, a lesson_id, and a url.
• Validate that the Readings url must start with http:// or https://. Use a regular expression.
• Validate that Courses have a course_code and a name.
• Validate that the course_code is unique within a given term_id.
• Validate that the course_code starts with three letters and ends with three numbers. Use a regular expression.

Person B:

• Associate lessons with readings (both directions). When a lesson is destroyed, its readings should be automatically destroyed.
• Associate lessons with courses (both directions). When a course is destroyed, its lessons should be automatically destroyed.
• Associate courses with course_instructors (both directions). If the course has any instructors associated with it, the course should not be deletable.
• Associate lessons with their in_class_assignments (both directions).
• Set up a Course to have many readings through the Course's lessons.
• Validate that Schools must have name.
• Validate that Terms must have name, starts_on, ends_on, and school_id.
• Validate that the User has a first_name, a last_name, and an email.
• Validate that the User's email is unique.
• Validate that the User's email has the appropriate form for an e-mail address. Use a regular expression.
• Validate that the User's photo_url must start with http:// or https://. Use a regular expression.
• Validate that Assignments have a course_id, name, and percent_of_grade.
• Validate that the Assignment name is unique within a given course_id.

Don't forget to write tests for each of these before coding them!

Hard Mode

After merging, add the following validations and associations, then merge again:

Person A:

• Associate course_instructors with instructors (who happen to be users)
• Associate assignments with assignment_grades (both directions)
• Set up a Course to have many instructors through the Course's course_instructors.
• Validate that an Assignment's due_at field is not before the Assignment's active_at.

Person B:

• Associate CourseStudents with students (who happen to be users)
• Associate CourseStudents with assignment_grades (both directions)
• Set up a Course to have many students through the course's course_students.
• Associate a Course with its ONE primary_instructor. This primary instructor is the one who is referenced by a course_instructor which has its primary flag set to true.

Again, don't forget to write tests!

Nightmare Mode

Although you've set up associations between these records, there's no telling what order the associated records will come back in. For instance, when you call course.assignments, they may or may not be sorted by the due date.

After merging hard mode, modify the associations to do the following, then merge again:

Person A:

• A Course's assignments should be ordered by due_at, then active_at.

Person B:

• A Course's students should be ordered by last_name, then first_name.

Then, together:

• Associate Lessons with their child_lessons (and vice-versa). Sort the child_lessons by id.

(And, of course, tests tests tests).