graphql: assignment override types

closes RECNVS-27

Test plan:
  * create different types of overrides for assignment(s)
  * make sure you can view the overrides with graphql

Change-Id: I557e1e8b26f8ead6c26bbddb5e09fd5ac425d421
Reviewed-on: https://gerrit.instructure.com/138381
Tested-by: Jenkins
Reviewed-by: Michael Jasper <mjasper@instructure.com>
QA-Review: Collin Parrish <cparrish@instructure.com>
Product-Review: Cameron Matheson <cameron@instructure.com>

app/graphql/types/assignment_override_type.rb

@@ -0,0 +1,67 @@
+module Types
+  AssignmentOverrideType = GraphQL::ObjectType.define do
+    name "AssignmentOverride"
+
+    interfaces [Interfaces::TimestampInterface]
+
+    field :_id, !types.ID, "legacy canvas id", property: :id
+
+    field :assignment, AssignmentType, resolve: ->(override, _, _) {
+      Loaders::AssociationLoader.for(AssignmentOverride, :assignment)
+        .load(override)
+        .then { override.assignment }
+    }
+
+    field :title, types.String
+
+    field :set, AssignmentOverrideSetUnion do
+      description "This object specifies what students this override applies to"
+
+      resolve ->(override, _, _) {
+        if override.set_type == "ADHOC"
+          # AdhocStudentsType will load the actual students
+          override
+        else
+          Loaders::AssociationLoader.for(AssignmentOverride, :set)
+            .load(override)
+            .then { override.set }
+        end
+      }
+    end
+
+    field :dueAt, TimeType, property: :due_at
+    field :lockAt, TimeType, property: :lock_at
+    field :unlockAt, TimeType, property: :unlock_at
+    field :allDay, types.Boolean, property: :all_day
+  end
+
+  AssignmentOverrideSetUnion = GraphQL::UnionType.define do
+    name "AssignmentOverrideSet"
+
+    description "Objects that can be assigned overridden dates"
+
+    possible_types [SectionType, GroupType, AdhocStudentsType]
+
+    resolve_type ->(obj, _) {
+      case obj
+      when CourseSection then SectionType
+      when Group then GroupType
+      when AssignmentOverride then AdhocStudentsType
+      end
+    }
+  end
+
+  AdhocStudentsType = GraphQL::ObjectType.define do
+    name "AdhocStudents"
+
+    description "A list of students that an `AssignmentOverride` applies to"
+
+    field :students, types[UserType], resolve: ->(override, _, _) {
+      Loaders::AssociationLoader.for(AssignmentOverride,
+                                     assignment_override_students: :user)
+      .load(override)
+      .then { override.assignment_override_students.map(&:user) }
+    }
+
+  end
+end

app/graphql/types/assignment_type.rb

@@ -90,6 +90,15 @@ module Types
        `AssignmentOverride` applies.",
       property: :only_visible_to_overrides
 
+    connection :assignmentOverrides, AssignmentOverrideType.connection_type, resolve:
+      ->(assignment, _, ctx) {
+        # this is the assignment overrides index method of loading
+        # overrides... there's also the totally different method found in
+        # assignment_overrides_json. they may not return the same results?
+        # ¯\_(ツ)_/¯
+        AssignmentOverrideApplicator.overrides_for_assignment_and_user(assignment, ctx[:current_user])
+      }
+
     connection :submissionsConnection, SubmissionType.connection_type do
       description "submissions for this assignment"
       resolve ->(assignment, _, ctx) {

schema.graphql

@@ -1,7 +1,25 @@
+# A list of students that an `AssignmentOverride` applies to
+type AdhocStudents {
+  students: [User]
+}
+
 type Assignment implements Node, Timestamped {
   # legacy canvas id
   _id: ID!
   assignmentGroup: AssignmentGroup
+  assignmentOverrides(
+    # Returns the elements in the list that come after the specified global ID.
+    after: String
+
+    # Returns the elements in the list that come before the specified global ID.
+    before: String
+
+    # Returns the first _n_ elements from the list.
+    first: Int
+
+    # Returns the last _n_ elements from the list.
+    last: Int
+  ): AssignmentOverrideConnection
   course: Course
   createdAt: Time
   description: String
@@ -126,6 +144,43 @@ input AssignmentInput {
   name: String!
 }
 
+type AssignmentOverride implements Timestamped {
+  # legacy canvas id
+  _id: ID!
+  allDay: Boolean
+  assignment: Assignment
+  createdAt: Time
+  dueAt: Time
+  lockAt: Time
+
+  # This object specifies what students this override applies to
+  set: AssignmentOverrideSet
+  title: String
+  unlockAt: Time
+  updatedAt: Time
+}
+
+# The connection type for AssignmentOverride.
+type AssignmentOverrideConnection {
+  # A list of edges.
+  edges: [AssignmentOverrideEdge]
+
+  # Information to aid in pagination.
+  pageInfo: PageInfo!
+}
+
+# An edge in a connection.
+type AssignmentOverrideEdge {
+  # A cursor for use in pagination.
+  cursor: String!
+
+  # The item at the end of the edge.
+  node: AssignmentOverride
+}
+
+# Objects that can be assigned overridden dates
+union AssignmentOverrideSet = AdhocStudents | Group | Section
+
 # States that an Assignment can be in
 enum AssignmentState {
   deleted

spec/graphql/types/assignment_override_type_spec.rb

@@ -0,0 +1,63 @@
+#
+# Copyright (C) 2017 - present Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+require File.expand_path(File.dirname(__FILE__) + '/../../spec_helper')
+require File.expand_path(File.dirname(__FILE__) + '/../../helpers/graphql_type_tester')
+
+describe Types::AssignmentOverrideType do
+  let_once(:course) { course_factory(active_all: true) }
+  let_once(:teacher) { teacher_in_course(course: course).user }
+  let_once(:student) { student_in_course(course: course).user }
+  let_once(:section) { course.course_sections.create! name: "section" }
+  let_once(:group) {
+    gc = assignment.group_category = GroupCategory.create! name: "asdf", context: course
+    gc.groups.create! name: "group", context: course
+  }
+  let_once(:assignment) { course.assignments.create! name: "asdf" }
+  let_once(:adhoc_override) {
+    assignment.assignment_overrides.new(set_type: "ADHOC").tap { |override|
+      override.assignment_override_students.build(assignment: assignment, user: student, assignment_override: override)
+      override.save!
+    }
+  }
+  let_once(:group_override) { assignment.assignment_overrides.create!(set: group) }
+  let_once(:section_override) { assignment.assignment_overrides.create!(set: section) }
+
+  def assignment_override_type(override)
+    GraphQLTypeTester.new(Types::AssignmentOverrideType, override)
+  end
+
+  it "works" do
+    override_type = assignment_override_type(adhoc_override)
+    expect(override_type._id).to eq adhoc_override.id
+    expect(override_type.title).to eq adhoc_override.title
+  end
+
+  it "returns override sets" do
+    expect(assignment_override_type(section_override).set).to eq section
+    expect(assignment_override_type(group_override).set).to eq group
+    expect(assignment_override_type(adhoc_override).set).to eq adhoc_override
+  end
+
+  describe Types::AdhocStudentsType do
+    let(:adhoc_students_type) { GraphQLTypeTester.new(Types::AdhocStudentsType, adhoc_override) }
+    it "it returns students" do
+      expect(adhoc_students_type.students).to eq [student]
+    end
+  end
+end