add grading period group association to enrollment terms

This adds the assocations required by the referenced ticket. Remaining
requirements for this ticket will be resolved in subsequent commits.

refs CNVS-26725

test plan:
1. run all the specs
2. confirm that they all pass

Change-Id: I0832a080582b4b99f63e546b0f56792b559d2692
Reviewed-on: https://gerrit.instructure.com/79113
Tested-by: Jenkins
Reviewed-by: Spencer Olson <solson@instructure.com>
QA-Review: KC Naegle <knaegle@instructure.com>
Product-Review: Cameron Matheson <cameron@instructure.com>

app/models/enrollment_term.rb

@@ -1,5 +1,5 @@
 #
-# Copyright (C) 2011 Instructure, Inc.
+# Copyright (C) 2011-2016 Instructure, Inc.
 #
 # This file is part of Canvas.
 #
@@ -23,6 +23,8 @@ class EnrollmentTerm < ActiveRecord::Base
 
   attr_accessible :name, :start_at, :end_at
   belongs_to :root_account, :class_name => 'Account'
+  belongs_to :grading_period_group, inverse_of: :enrollment_terms
+  has_many :grading_periods, through: :grading_period_group
   has_many :enrollment_dates_overrides
   has_many :courses
   has_many :enrollments, :through => :courses
@@ -33,6 +35,7 @@ class EnrollmentTerm < ActiveRecord::Base
 
   before_validation :verify_unique_sis_source_id
   before_save :update_courses_later_if_necessary
+  before_save :destroy_orphaned_grading_period_group
 
   include StickySisFields
   are_sis_sticky :name, :start_at, :end_at
@@ -164,5 +167,18 @@ class EnrollmentTerm < ActiveRecord::Base
     save!
   end
 
+  def destroy_orphaned_grading_period_group
+    is_being_destroyed = workflow_state_changed? && deleted?
+    had_previous_group = grading_period_group_id_changed? && grading_period_group_id_was
+
+    if is_being_destroyed || had_previous_group
+      grading_period_group_criteria = { grading_period_group_id: grading_period_group_id_was }
+      remaining_terms = EnrollmentTerm.active.where(grading_period_group_criteria).where.not(id: self)
+      unless remaining_terms.exists?
+        GradingPeriodGroup.destroy(grading_period_group_id_was)
+      end
+    end
+  end
+
   scope :active, -> { where("enrollment_terms.workflow_state<>'deleted'") }
 end

app/models/grading_period_group.rb

@@ -2,11 +2,12 @@ class GradingPeriodGroup < ActiveRecord::Base
   include Canvas::SoftDeletable
 
   attr_accessible # None of this model's attributes are mass-assignable
-  belongs_to :course
   belongs_to :account
+  belongs_to :course
   has_many :grading_periods, dependent: :destroy
+  has_many :enrollment_terms, inverse_of: :grading_period_group
 
-  validate :belongs_to_course_or_account_exclusive
+  validate :associated_with_course_or_account_or_enrollment_term?
 
   set_policy do
     given { |user| multiple_grading_periods_enabled? && (course || account).grants_right?(user, :read) }
@@ -24,18 +25,37 @@ class GradingPeriodGroup < ActiveRecord::Base
   end
 
   private
-  def belongs_to_course_or_account_exclusive
-    if course.blank? && account.blank?
-      errors.add(:course_id, t("cannot be nil when account_id is nil"))
-      errors.add(:account_id, t("cannot be nil when course_id is nil"))
-    end
 
-    if course.present? && account.present?
+  def associated_with_course_or_account_or_enrollment_term?
+    has_enrollment_terms = enrollment_terms.loaded? ? enrollment_terms.any?(&:active?) : enrollment_terms.active.exists?
+    if has_enrollment_terms
+      validate_with_enrollment_terms
+    else
+      validate_without_enrollment_terms if active?
+    end
+  end
+
+  def validate_without_enrollment_terms
+    if course_id.blank? && account_id.blank?
+      errors.add(:enrollment_terms, t("cannot be empty when course_id is nil and account_id is nil"))
+    elsif course_id.present? && account_id.present?
       errors.add(:course_id, t("cannot be present when account_id is present"))
       errors.add(:account_id, t("cannot be present when course_id is present"))
     end
   end
 
+  def validate_with_enrollment_terms
+    if enrollment_terms.loaded?
+      account_ids = enrollment_terms.map(&:root_account_id)
+    else
+      account_ids = enrollment_terms.uniq.pluck(:root_account_id)
+    end
+    account_ids << self.account_id if self.account_id.present?
+    if account_ids.uniq.count > 1
+      errors.add(:enrollment_terms, t("cannot be associated with different accounts"))
+    end
+  end
+
   def account_grading_period_allowed?
     !!(account && account.feature_allowed?(:multiple_grading_periods))
   end

db/migrate/20160509131527_add_grading_period_group_id_to_enrollment_term.rb

@@ -0,0 +1,13 @@
+class AddGradingPeriodGroupIdToEnrollmentTerm < ActiveRecord::Migration
+  tag :predeploy
+
+  def up
+    add_column :enrollment_terms, :grading_period_group_id, :integer, :limit => 8
+    add_index :enrollment_terms, :grading_period_group_id
+    add_foreign_key :enrollment_terms, :grading_period_groups
+  end
+
+  def down
+    remove_column :enrollment_terms, :grading_period_group_id
+  end
+end

spec/factories/grading_period_factory.rb

@@ -1,5 +1,5 @@
 #
-# Copyright (C) 2015 Instructure, Inc.
+# Copyright (C) 2015-2016 Instructure, Inc.
 #
 # This file is part of Canvas.
 #
@@ -64,3 +64,13 @@ def create_grading_periods_for(context, opts={})
   end
 end
 
+module Factories
+  class GradingPeriodGroupHelper
+    def create_for_enrollment_term(term)
+      grading_period_group = GradingPeriodGroup.new
+      grading_period_group.enrollment_terms << term
+      grading_period_group.save!
+      grading_period_group
+    end
+  end
+end

spec/models/enrollment_term_spec.rb

@@ -1,5 +1,5 @@
 #
-# Copyright (C) 2011 Instructure, Inc.
+# Copyright (C) 2011-2016 Instructure, Inc.
 #
 # This file is part of Canvas.
 #
@@ -19,6 +19,29 @@
 require File.expand_path(File.dirname(__FILE__) + '/../spec_helper.rb')
 
 describe EnrollmentTerm do
+  let(:group_helper) { Factories::GradingPeriodGroupHelper.new }
+
+  describe "validation" do
+    before(:once) do
+      @root_account = account_model
+    end
+
+    it "is valid with no grading_period_group" do
+      term = EnrollmentTerm.new
+      term.root_account = @root_account
+      expect(term).to be_valid
+    end
+
+    it "is valid with a grading period group shared with another enrollment term" do
+      term_1 = @root_account.enrollment_terms.create!
+      term_2 = @root_account.enrollment_terms.create!
+      group = group_helper.create_for_enrollment_term(term_1)
+      term_2.grading_period_group = group
+      expect(term_1).to be_valid
+      expect(term_2).to be_valid
+    end
+  end
+
   it "should handle the translated Default Term names correctly" do
     begin
       account_model
@@ -84,14 +107,63 @@ describe EnrollmentTerm do
     end
   end
 
+  describe "saving" do
+    before(:once) do
+      @account = account_model
+    end
+
+    context "when removing an associated grading period group" do
+      it "destroys the group when unshared" do
+        term = @account.enrollment_terms.create!
+        group = group_helper.create_for_enrollment_term(term)
+        term.grading_period_group = nil
+        term.save!
+        expect(GradingPeriodGroup.active.find_by_id(group.id)).to be_nil
+      end
+
+      it "does not destroy the group when associated with other enrollment terms" do
+        term_1 = @account.enrollment_terms.create!
+        group = group_helper.create_for_enrollment_term(term_1)
+        term_2 = @account.enrollment_terms.create!
+        term_2.update_attribute(:grading_period_group, group)
+        term_1.grading_period_group = nil
+        term_1.save!
+        expect(GradingPeriodGroup.active.find_by_id(group.id)).to eq(group)
+      end
+    end
+
+    context "when replacing an associated grading period group" do
+      it "destroys the group when unshared" do
+        term = @account.enrollment_terms.create!
+        group_1 = group_helper.create_for_enrollment_term(term)
+        group_2 = group_helper.create_for_enrollment_term(term)
+        expect(GradingPeriodGroup.active.find_by_id(group_1.id)).to be_nil
+        expect(GradingPeriodGroup.active.find_by_id(group_2.id)).to eq(group_2)
+      end
+
+      it "does not destroy the group when associated with other enrollment terms" do
+        term_1 = @account.enrollment_terms.create!
+        term_2 = @account.enrollment_terms.create!
+        group_1 = group_helper.create_for_enrollment_term(term_1)
+        group_1.enrollment_terms << term_2
+        group_1.save!
+        group_2 = group_helper.create_for_enrollment_term(term_1)
+        expect(GradingPeriodGroup.active.find_by_id(group_1.id)).to eq(group_1)
+        expect(GradingPeriodGroup.active.find_by_id(group_2.id)).to eq(group_2)
+      end
+    end
+  end
+
   describe "deletion" do
+    before(:once) do
+      @account = account_model
+    end
+
     it "should not be able to delete a default term" do
-      account_model
       expect { @account.default_enrollment_term.destroy }.to raise_error
     end
 
     it "should not be able to delete an enrollment term with active courses" do
-      account_model
       @term = @account.enrollment_terms.create!
       course account: @account
       @course.enrollment_term = @term
@@ -100,9 +172,34 @@ describe EnrollmentTerm do
       expect { @term.destroy }.to raise_error
 
       @course.destroy
-
       @term.destroy
     end
+
+    it "destroys an associated grading period group" do
+      term = @account.enrollment_terms.create!
+      group = group_helper.create_for_enrollment_term(term)
+      term.destroy
+      expect(GradingPeriodGroup.active.find_by_id(group.id)).to be_nil
+    end
+
+    it "does not destroy grading period groups associated with other active enrollment terms" do
+      term_1 = @account.enrollment_terms.create!
+      group = group_helper.create_for_enrollment_term(term_1)
+      term_2 = @account.enrollment_terms.create!
+      term_2.update_attribute(:grading_period_group, group)
+      term_1.destroy
+      expect(GradingPeriodGroup.active.find_by_id(group.id)).to eql(group)
+    end
+
+    it "destroys grading period groups associated with other deleted enrollment terms" do
+      term_1 = @account.enrollment_terms.create!
+      group = group_helper.create_for_enrollment_term(term_1)
+      term_2 = @account.enrollment_terms.create!
+      term_2.update_attribute(:grading_period_group, group)
+      term_1.destroy
+      term_2.destroy
+      expect(GradingPeriodGroup.active.find_by_id(group.id)).to be_nil
+    end
   end
 
   describe "counts" do
@@ -136,4 +233,54 @@ describe EnrollmentTerm do
       end
     end
   end
+
+  describe "#grading_period_group" do
+    before(:once) do
+      @account = account_model
+    end
+
+    it "returns the associated grading period group" do
+      term = @account.enrollment_terms.create!
+      group = group_helper.create_for_enrollment_term(term)
+      expect(term.grading_period_group).to eq group
+    end
+
+    it "returns nil when no grading period group is associated" do
+      term = @account.enrollment_terms.create!
+      expect(term.grading_period_group).to be_nil
+    end
+  end
+
+  describe "#grading_periods" do
+    before(:once) do
+      @account = account_model
+    end
+
+    def create_grading_period(group, start_weeks, end_weeks)
+      group.grading_periods.create!({
+        start_date: start_weeks.weeks.ago,
+        end_date: end_weeks.weeks.ago,
+        title: "Example Grading Period"
+      })
+    end
+
+    it "returns the grading periods from the associated grading period group" do
+      term = @account.enrollment_terms.create!
+      group = group_helper.create_for_enrollment_term(term)
+      period_1 = create_grading_period(group, 5, 3)
+      period_2 = create_grading_period(group, 3, 1)
+      expect(term.grading_periods).to match_array [period_1, period_2]
+    end
+
+    it "returns an empty array when the associated group has no grading periods" do
+      term = @account.enrollment_terms.create!
+      group_helper.create_for_enrollment_term(term)
+      expect(term.grading_periods).to eq []
+    end
+
+    it "returns an empty array when no grading period group is associated" do
+      term = @account.enrollment_terms.create!
+      expect(term.grading_periods).to eq []
+    end
+  end
 end

spec/models/grading_period_group_spec.rb

@@ -1,5 +1,5 @@
 #
-# Copyright (C) 2014 Instructure, Inc.
+# Copyright (C) 2014-2016 Instructure, Inc.
 #
 # This file is part of Canvas.
 #
@@ -19,39 +19,121 @@
 require File.expand_path(File.dirname(__FILE__) + '/../spec_helper.rb')
 
 describe GradingPeriodGroup do
+  let(:group_helper) { Factories::GradingPeriodGroupHelper.new }
+
   describe "validation" do
-    it "should not be valid without a course or account" do
-      grading_period_group = GradingPeriodGroup.new
-      expect(grading_period_group).to_not be_valid
+    it "is valid with only an active enrollment term" do
+      enrollment_term = Account.default.enrollment_terms.create!
+      group = GradingPeriodGroup.new
+      group.enrollment_terms << enrollment_term
+      expect(group).to be_valid
     end
 
-    it "should not be valid with a course AND an account" do
+    it "is valid with an account" do
+      group = GradingPeriodGroup.new
+      group.account = Account.default
+      expect(group).to be_valid
+    end
+
+    it "is valid with a course" do
+      course = Course.create!(account: Account.default)
+      group = GradingPeriodGroup.new
+      group.course = course
+      expect(group).to be_valid
+    end
+
+    it "is valid with both an account and enrollment terms" do
+      term_1 = Account.default.enrollment_terms.create!
+      term_2 = Account.default.enrollment_terms.create!
+      group = GradingPeriodGroup.new
+      group.account = Account.default
+      group.enrollment_terms << term_1
+      group.enrollment_terms << term_2
+      expect(group).to be_valid
+    end
+
+    it "is not valid without an account, a course, or an enrollment term" do
+      group = GradingPeriodGroup.new
+      expect(group).not_to be_valid
+    end
+
+    it "is not valid with both an account and a course" do
+      course = Course.create!(account: Account.default)
+      group = GradingPeriodGroup.new
+      group.account = Account.default
+      group.course = course
+      expect(group).not_to be_valid
+    end
+
+    it "is valid with only deleted enrollment terms and is deleted" do
+      enrollment_term = Account.default.enrollment_terms.create!
+      enrollment_term.destroy
+      group = GradingPeriodGroup.new
+      group.enrollment_terms << enrollment_term
+      group.workflow_state = 'deleted'
+      expect(group).to be_valid
+    end
+
+    it "is not valid with only deleted enrollment terms and not deleted" do
+      enrollment_term = Account.default.enrollment_terms.create!
+      enrollment_term.destroy
+      group = GradingPeriodGroup.new
+      group.enrollment_terms << enrollment_term
+      expect(group).not_to be_valid
+    end
+
+    it "is not valid with only deleted enrollment terms and undeleted" do
+      enrollment_term = Account.default.enrollment_terms.create!
+      group = group_helper.create_for_enrollment_term(enrollment_term)
+      enrollment_term.destroy
+      group.reload
+      group.workflow_state = 'active'
+      expect(group).not_to be_valid
+    end
+
+    it "is not valid with an account and enrollment terms from different accounts" do
+      group = GradingPeriodGroup.new
+      group.account = Account.default
+      other_account = account_model
+      term = other_account.enrollment_terms.create!
+      group.enrollment_terms << term
+      expect(group).not_to be_valid
+    end
+
+    it "is not valid with enrollment terms associated with different accounts" do
+      account_1 = account_model
+      account_2 = account_model
+      term_1 = account_1.enrollment_terms.create!
+      term_2 = account_2.enrollment_terms.create!
+      group = GradingPeriodGroup.new
+      group.enrollment_terms << term_1
+      group.enrollment_terms << term_2
+      expect(group).not_to be_valid
+    end
+
+    it "is not valid with enrollment terms with different accounts and workflow states" do
+      account_1 = account_model
+      account_2 = account_model
+      term_1 = account_1.enrollment_terms.create!
+      term_2 = account_2.enrollment_terms.create!
+      term_2.destroy
+      group = GradingPeriodGroup.new
+      group.enrollment_terms << term_1
+      group.enrollment_terms << term_2
+      expect(group).not_to be_valid
+    end
+
+    it "is not able to mass-assign the account id" do
+      group = GradingPeriodGroup.new(account_id: Account.default.id)
+      expect(group.account_id).to be_nil
+      expect(group.account).to be_nil
+    end
+
+    it "is not able to mass-assign the course id" do
       course = course()
-      grading_period_group = course.grading_period_groups.new
-      grading_period_group.account = Account.default
-      expect(grading_period_group).to_not be_valid
-    end
-
-    it "should be valid with an account" do
-      grading_period_group = Account.default.grading_period_groups.new
-      expect(grading_period_group).to be_valid
-    end
-
-    it "should not be able to mass-assign the account id" do
-      grading_period_group = GradingPeriodGroup.new(account_id: Account.default.id)
-      expect(grading_period_group).to_not be_valid
-    end
-
-    it "should be valid with a course" do
-      course = course()
-      grading_period_group = course.grading_period_groups.new
-      expect(grading_period_group).to be_valid
-    end
-
-    it "should not be able to mass-assign the course id" do
-      course = course()
-      grading_period_group = GradingPeriodGroup.new(course_id: course.id)
-      expect(grading_period_group).to_not be_valid
+      group = GradingPeriodGroup.new(course_id: course.id)
+      expect(group.course_id).to be_nil
+      expect(group.course).to be_nil
     end
   end
 
@@ -273,4 +355,17 @@ describe GradingPeriodGroup do
       end
     end
   end
+
+  describe "#enrollment_terms" do
+    it "returns the associated enrollment terms" do
+      account = Account.default
+      term_1 = account.enrollment_terms.create!
+      term_2 = account.enrollment_terms.create!
+      group = group_helper.create_for_enrollment_term(term_1)
+      term_2.update_attribute(:grading_period_group, group)
+      group.save!
+      group.reload
+      expect(group.enrollment_terms).to match_array([term_1, term_2])
+    end
+  end
 end