Backport of multiple_assignees_feature [ci skip]

app/assets/javascripts/subscription_select.js

@@ -19,8 +19,8 @@
               return label;
             };
           })(this),
-          clicked: function(item, $el, e) {
-            return e.preventDefault();
+          clicked: function(options) {
+            return options.e.preventDefault();
           },
           id: function(obj, el) {
             return $(el).data("id");

app/assets/stylesheets/framework/avatar.scss

@@ -93,3 +93,14 @@
     align-self: center;
   }
 }
+
+.avatar-counter {
+  background-color: $gray-darkest;
+  color: $white-light;
+  border: 1px solid $border-color;
+  border-radius: 1em;
+  font-family: $regular_font;
+  font-size: 9px;
+  line-height: 16px;
+  text-align: center;
+}

app/assets/stylesheets/framework/dropdowns.scss

@@ -251,11 +251,9 @@
   }
   .dropdown-header {
-    color: $gl-text-color;
+    color: $gl-text-color-secondary;
     font-size: 13px;
-    font-weight: 600;
     line-height: 22px;
-    text-transform: capitalize;
     padding: 0 16px;
   }
@@ -337,8 +335,8 @@
 .dropdown-menu-user {
   .avatar {
     float: left;
-    width: 30px;
-    height: 30px;
+    width: 2 * $gl-padding;
+    height: 2 * $gl-padding;
     margin: 0 10px 0 0;
   }
 }
@@ -381,6 +379,7 @@
 .dropdown-menu-selectable {
   a {
     padding-left: 26px;
+    position: relative;
     &.is-indeterminate,
     &.is-active {
@@ -406,6 +405,9 @@
     &.is-active::before {
       content: "\f00c";
+      position: absolute;
+      top: 50%;
+      transform: translateY(-50%);
     }
   }
 }

app/assets/stylesheets/framework/lists.scss

@@ -255,6 +255,7 @@ ul.controls {
       .avatar-inline {
         margin-left: 0;
         margin-right: 0;
+        margin-bottom: 0;
       }
     }
   }

app/assets/stylesheets/pages/boards.scss

@@ -207,8 +207,13 @@
     margin-bottom: 5px;
   }
-  &.is-active {
+  &.is-active,
+  &.is-active .card-assignee:hover a {
     background-color: $row-hover;
+
+    &:first-child:not(:only-child) {
+      box-shadow: -10px 0 10px 1px $row-hover;
+    }
   }
   .label {
@@ -224,7 +229,7 @@
 }
 .card-title {
-  margin: 0;
+  margin: 0 30px 0 0;
   font-size: 1em;
   line-height: inherit;
@@ -240,10 +245,69 @@
   min-height: 20px;
   .card-assignee {
-    margin-left: auto;
-    margin-right: 5px;
-    padding-left: 10px;
+    display: flex;
+    justify-content: flex-end;
+    position: absolute;
+    right: 15px;
     height: 20px;
+    width: 20px;
+
+    .avatar-counter {
+      display: none;
+      vertical-align: middle;
+      min-width: 20px;
+      line-height: 19px;
+      height: 20px;
+      padding-left: 2px;
+      padding-right: 2px;
+      border-radius: 2em;
+    }
+
+    img {
+      vertical-align: top;
+    }
+
+    a {
+      position: relative;
+      margin-left: -15px;
+    }
+
+    a:nth-child(1) {
+      z-index: 3;
+    }
+
+    a:nth-child(2) {
+      z-index: 2;
+    }
+
+    a:nth-child(3) {
+      z-index: 1;
+    }
+
+    a:nth-child(4) {
+      display: none;
+    }
+
+    &:hover {
+      .avatar-counter {
+        display: inline-block;
+      }
+
+      a {
+        position: static;
+        background-color: $white-light;
+        transition: background-color 0s;
+        margin-left: auto;
+
+        &:nth-child(4) {
+          display: block;
+        }
+
+        &:first-child:not(:only-child) {
+          box-shadow: -10px 0 10px 1px $white-light;
+        }
+      }
+    }
   }
   .avatar {

app/assets/stylesheets/pages/diff.scss

@@ -570,14 +570,7 @@
 .diff-comments-more-count,
 .diff-notes-collapse {
-  background-color: $gray-darkest;
-  color: $white-light;
-  border: 1px solid $white-light;
-  border-radius: 1em;
-  font-family: $regular_font;
-  font-size: 9px;
-  line-height: 17px;
-  text-align: center;
+  @extend .avatar-counter;
 }
 .diff-notes-collapse {

app/assets/stylesheets/pages/issuable.scss

@@ -95,10 +95,15 @@
 }
 .right-sidebar {
-  a {
+  a,
+  .btn-link {
     color: inherit;
   }
+  .btn-link {
+    outline: none;
+  }
+
   .issuable-header-text {
     margin-top: 7px;
   }
@@ -215,6 +220,10 @@
       }
     }
+    .assign-yourself .btn-link {
+      padding-left: 0;
+    }
+
     .light {
       font-weight: normal;
     }
@@ -239,6 +248,10 @@
       margin-left: 0;
     }
+    .assignee .user-list .avatar {
+      margin: 0;
+    }
+
     .username {
       display: block;
       margin-top: 4px;
@@ -301,6 +314,10 @@
         margin-top: 0;
       }
+      .sidebar-avatar-counter {
+        padding-top: 2px;
+      }
+
       .todo-undone {
         color: $gl-link-color;
       }
@@ -309,10 +326,15 @@
         display: none;
       }
-      .avatar:hover {
+      .avatar:hover,
+      .avatar-counter:hover {
         border-color: $issuable-sidebar-color;
       }
+      .avatar-counter:hover {
+        color: $issuable-sidebar-color;
+      }
+
       .btn-clipboard {
         border: none;
         color: $issuable-sidebar-color;
@@ -322,6 +344,17 @@
           color: $gl-text-color;
         }
       }
+
+      &.multiple-users {
+        display: flex;
+        justify-content: center;
+      }
+    }
+
+    .sidebar-avatar-counter {
+      width: 24px;
+      height: 24px;
+      border-radius: 12px;
     }
     .sidebar-collapsed-user {
@@ -332,6 +365,37 @@
     .issuable-header-btn {
       display: none;
     }
+
+    .multiple-users {
+      height: 24px;
+      margin-bottom: 17px;
+      margin-top: 4px;
+      padding-bottom: 4px;
+
+      .btn-link {
+        padding: 0;
+        border: 0;
+
+        .avatar {
+          margin: 0;
+        }
+      }
+
+      .btn-link:first-child {
+        position: absolute;
+        left: 10px;
+        z-index: 1;
+      }
+
+      .btn-link:last-child {
+        position: absolute;
+        right: 10px;
+
+        &:hover {
+          text-decoration: none;
+        }
+      }
+    }
   }
   a {
@@ -380,17 +444,21 @@
 }
 .participants-list {
+  display: flex;
+  flex-wrap: wrap;
+  justify-content: space-between;
   margin: -5px;
 }
+.user-list {
+  display: flex;
+  flex-wrap: wrap;
+}
+
 .participants-author {
-  display: inline-block;
+  flex-basis: 14%;
   padding: 5px;
-  &:nth-of-type(7n) {
-    padding-right: 0;
-  }
-
   .author_link {
     display: block;
   }
@@ -400,13 +468,39 @@
   }
 }
-.participants-more {
+.user-item {
+  display: inline-block;
+  padding: 5px;
+  flex-basis: 20%;
+
+  .user-link {
+    display: inline-block;
+  }
+}
+
+.participants-more,
+.user-list-more {
   margin-top: 5px;
   margin-left: 5px;
-  a {
+  a,
+  .btn-link {
     color: $gl-text-color-secondary;
   }
+
+  .btn-link {
+    outline: none;
+    padding: 0;
+  }
+
+  .btn-link:hover {
+    @extend a:hover;
+    text-decoration: none;
+  }
+
+  .btn-link:focus {
+    text-decoration: none;
+  }
 }
 .issuable-form-padding-top {
@@ -499,6 +593,19 @@
   }
 }
+.issuable-list li,
+.issue-info-container .controls {
+  .avatar-counter {
+    display: inline-block;
+    vertical-align: middle;
+    min-width: 16px;
+    line-height: 14px;
+    height: 16px;
+    padding-left: 2px;
+    padding-right: 2px;
+  }
+}
+
 .time_tracker {
   padding-bottom: 0;
   border-bottom: 0;

app/controllers/concerns/issuable_actions.rb

@@ -66,6 +66,7 @@ module IssuableActions
       :milestone_id,
       :state_event,
       :subscription_event,
+      assignee_ids: [],
       label_ids: [],
       add_label_ids: [],
       remove_label_ids: []

app/controllers/concerns/issuable_collections.rb

@@ -43,7 +43,7 @@ module IssuableCollections
   end
   def issues_collection
-    issues_finder.execute.preload(:project, :author, :assignee, :labels, :milestone, project: :namespace)
+    issues_finder.execute.preload(:project, :author, :assignees, :labels, :milestone, project: :namespace)
   end
   def merge_requests_collection

app/controllers/projects/boards/issues_controller.rb

@@ -82,7 +82,7 @@ module Projects
           labels: true,
           only: [:id, :iid, :title, :confidential, :due_date, :relative_position],
           include: {
-            assignee: { only: [:id, :name, :username], methods: [:avatar_url] },
+            assignees: { only: [:id, :name, :username], methods: [:avatar_url] },
             milestone: { only: [:id, :title] }
           },
           user: current_user

app/controllers/projects/issues_controller.rb

@@ -67,7 +67,7 @@ class Projects::IssuesController < Projects::ApplicationController
   def new
     params[:issue] ||= ActionController::Parameters.new(
-      assignee_id: ""
+      assignee_ids: ""
     )
     build_params = issue_params.merge(
       merge_request_to_resolve_discussions_of: params[:merge_request_to_resolve_discussions_of],
@@ -150,7 +150,7 @@ class Projects::IssuesController < Projects::ApplicationController
         if @issue.valid?
           render json: @issue.to_json(methods: [:task_status, :task_status_short],
                                       include: { milestone: {},
-                                                 assignee: { only: [:name, :username], methods: [:avatar_url] },
+                                                 assignees: { only: [:id, :name, :username], methods: [:avatar_url] },
                                                  labels: { methods: :text_color } })
         else
           render json: { errors: @issue.errors.full_messages }, status: :unprocessable_entity
@@ -275,7 +275,7 @@ class Projects::IssuesController < Projects::ApplicationController
   def issue_params
     params.require(:issue).permit(
       :title, :assignee_id, :position, :description, :confidential,
-      :milestone_id, :due_date, :state_event, :task_num, :lock_version, label_ids: []
+      :milestone_id, :due_date, :state_event, :task_num, :lock_version, label_ids: [], assignee_ids: [],
     )
   end

app/finders/issuable_finder.rb

@@ -231,7 +231,7 @@ class IssuableFinder
     when 'created-by-me', 'authored'
       items.where(author_id: current_user.id)
     when 'assigned-to-me'
-      items.where(assignee_id: current_user.id)
+      items.assigned_to(current_user)
     else
       items
     end

app/finders/issues_finder.rb

@@ -26,17 +26,28 @@ class IssuesFinder < IssuableFinder
     IssuesFinder.not_restricted_by_confidentiality(current_user)
   end
+  def by_assignee(items)
+    if assignee
+      items.assigned_to(assignee)
+    elsif no_assignee?
+      items.unassigned
+    elsif assignee_id? || assignee_username? # assignee not found
+      items.none
+    else
+      items
+    end
+  end
+
   def self.not_restricted_by_confidentiality(user)
-    return Issue.where('issues.confidential IS NULL OR issues.confidential IS FALSE') if user.blank?
+    return Issue.where('issues.confidential IS NOT TRUE') if user.blank?
     return Issue.all if user.admin?
     Issue.where('
-      issues.confidential IS NULL
-      OR issues.confidential IS FALSE
+      issues.confidential IS NOT TRUE
       OR (issues.confidential = TRUE
         AND (issues.author_id = :user_id
-          OR issues.assignee_id = :user_id
+          OR EXISTS (SELECT TRUE FROM issue_assignees WHERE user_id = :user_id AND issue_id = issues.id)
           OR issues.project_id IN(:project_ids)))',
       user_id: user.id,
       project_ids: user.authorized_projects(Gitlab::Access::REPORTER).select(:id))

app/helpers/form_helper.rb

@@ -15,4 +15,37 @@ module FormHelper
         end
     end
   end
+
+  def issue_dropdown_options(issuable, has_multiple_assignees = true)
+    options = {
+      toggle_class: 'js-user-search js-assignee-search',
+      title: 'Select assignee',
+      filter: true,
+      dropdown_class: 'dropdown-menu-user dropdown-menu-selectable dropdown-menu-assignee',
+      placeholder: 'Search users',
+      data: {
+        first_user: current_user&.username,
+        null_user: true,
+        current_user: true,
+        project_id: issuable.project.try(:id),
+        field_name: "#{issuable.class.model_name.param_key}[assignee_ids][]",
+        default_label: 'Assignee',
+        'max-select': 1,
+        'dropdown-header': 'Assignee',
+      }
+    }
+
+    if has_multiple_assignees
+      options[:toggle_class] += ' js-multiselect js-save-user-data'
+      options[:title] = 'Select assignee(s)'
+      options[:data][:multi_select] = true
+      options[:data][:'input-meta'] = 'name'
+      options[:data][:'always-show-selectbox'] = true
+      options[:data][:current_user_info] = current_user.to_json(only: [:id, :name])
+      options[:data][:'dropdown-header'] = 'Assignee(s)'
+      options[:data].delete(:'max-select')
+    end
+
+    options
+  end
 end

app/helpers/issuables_helper.rb

@@ -63,6 +63,16 @@ module IssuablesHelper
     end
   end
+  def users_dropdown_label(selected_users)
+    if selected_users.length == 0
+      "Unassigned"
+    elsif selected_users.length == 1
+      selected_users[0].name
+    else
+      "#{selected_users[0].name} + #{selected_users.length - 1} more"
+    end
+  end
+
   def user_dropdown_label(user_id, default_label)
     return default_label if user_id.nil?
     return "Unassigned" if user_id == "0"

app/mailers/emails/issues.rb

@@ -11,10 +11,12 @@ module Emails
       mail_answer_thread(@issue, issue_thread_options(updated_by_user_id, recipient_id))
     end
-    def reassigned_issue_email(recipient_id, issue_id, previous_assignee_id, updated_by_user_id)
+    def reassigned_issue_email(recipient_id, issue_id, previous_assignee_ids, updated_by_user_id)
       setup_issue_mail(issue_id, recipient_id)
-      @previous_assignee = User.find_by(id: previous_assignee_id) if previous_assignee_id
+      @previous_assignees = []
+      @previous_assignees = User.where(id: previous_assignee_ids) if previous_assignee_ids.any?
+
       mail_answer_thread(@issue, issue_thread_options(updated_by_user_id, recipient_id))
     end

app/models/concerns/issuable.rb

@@ -26,7 +26,6 @@ module Issuable
     cache_markdown_field :description, issuable_state_filter_enabled: true
     belongs_to :author, class_name: "User"
-    belongs_to :assignee, class_name: "User"
     belongs_to :updated_by, class_name: "User"
     belongs_to :milestone
     has_many :notes, as: :noteable, inverse_of: :noteable, dependent: :destroy do
@@ -65,11 +64,8 @@ module Issuable
     validates :title, presence: true, length: { maximum: 255 }
     scope :authored, ->(user) { where(author_id: user) }
-    scope :assigned_to, ->(u) { where(assignee_id: u.id)}
     scope :recent, -> { reorder(id: :desc) }
     scope :order_position_asc, -> { reorder(position: :asc) }
-    scope :assigned, -> { where("assignee_id IS NOT NULL") }
-    scope :unassigned, -> { where("assignee_id IS NULL") }
     scope :of_projects, ->(ids) { where(project_id: ids) }
     scope :of_milestones, ->(ids) { where(milestone_id: ids) }
     scope :with_milestone, ->(title) { left_joins_milestones.where(milestones: { title: title }) }
@@ -92,7 +88,6 @@ module Issuable
     attr_mentionable :description
     participant :author
-    participant :assignee
     participant :notes_with_associations
     strip_attributes :title
@@ -102,13 +97,6 @@ module Issuable
     after_save :update_assignee_cache_counts, if: :assignee_id_changed?
     after_save :record_metrics, unless: :imported?
-    def update_assignee_cache_counts
-      # make sure we flush the cache for both the old *and* new assignees(if they exist)
-      previous_assignee = User.find_by_id(assignee_id_was) if assignee_id_was
-      previous_assignee&.update_cache_counts
-      assignee&.update_cache_counts
-    end
-
     # We want to use optimistic lock for cases when only title or description are involved
     # http://api.rubyonrails.org/classes/ActiveRecord/Locking/Optimistic.html
     def locking_enabled?
@@ -237,10 +225,6 @@ module Issuable
     today? && created_at == updated_at
   end
-  def is_being_reassigned?
-    assignee_id_changed?
-  end
-
   def open?
     opened? || reopened?
   end
@@ -269,7 +253,11 @@ module Issuable
       # DEPRECATED
       repository: project.hook_attrs.slice(:name, :url, :description, :homepage)
     }
-    hook_data[:assignee] = assignee.hook_attrs if assignee
+    if self.is_a?(Issue)
+      hook_data[:assignees] = assignees.map(&:hook_attrs) if assignees.any?
+    else
+      hook_data[:assignee] = assignee.hook_attrs if assignee
+    end
     hook_data
   end
@@ -331,11 +319,6 @@ module Issuable
     false
   end
-  def assignee_or_author?(user)
-    # We're comparing IDs here so we don't need to load any associations.
-    author_id == user.id || assignee_id == user.id
-  end
-
   def record_metrics
     metrics = self.metrics || create_metrics
     metrics.record!

app/models/concerns/milestoneish.rb

@@ -40,7 +40,7 @@ module Milestoneish
   def issues_visible_to_user(user)
     memoize_per_user(user, :issues_visible_to_user) do
       IssuesFinder.new(user, issues_finder_params)
-        .execute.where(milestone_id: milestoneish_ids)
+        .execute.includes(:assignees).where(milestone_id: milestoneish_ids)
     end
   end

app/models/global_milestone.rb

@@ -36,7 +36,7 @@ class GlobalMilestone
     closed = count_by_state(milestones_by_state_and_title, 'closed')
     all = milestones_by_state_and_title.map { |(_, title), _| title }.uniq.count
-    { 
+    {
       opened: opened,
       closed: closed,
       all: all
@@ -86,7 +86,7 @@ class GlobalMilestone
   end
   def issues
-    @issues ||= Issue.of_milestones(milestoneish_ids).includes(:project, :assignee, :labels)
+    @issues ||= Issue.of_milestones(milestoneish_ids).includes(:project, :assignees, :labels)
   end
   def merge_requests
@@ -94,7 +94,7 @@ class GlobalMilestone
   end
   def participants
-    @participants ||= milestones.includes(:participants).map(&:participants).flatten.compact.uniq
+    @participants ||= milestones.map(&:participants).flatten.uniq
   end
   def labels