Issues API: Add None/Any option to assignee_id

app/finders/issuable_finder.rb

@@ -14,7 +14,7 @@
 #     project_id: integer
 #     milestone_title: string
 #     author_id: integer
-#     assignee_id: integer
+#     assignee_id: integer or 'None' or 'Any'
 #     search: string
 #     label_name: string
 #     sort: string
@@ -34,6 +34,11 @@ class IssuableFinder
   requires_cross_project_access unless: -> { project? }
+  # This is used as a common filter for None / Any
+  FILTER_NONE = 'None'.freeze
+  FILTER_ANY = 'Any'.freeze
+
+  # This is accepted as a deprecated filter and is also used in unassigning users
   NONE = '0'.freeze
   attr_accessor :current_user, :params
@@ -236,16 +241,20 @@ class IssuableFinder
   # rubocop: enable CodeReuse/ActiveRecord
   def assignee_id?
-    params[:assignee_id].present? && params[:assignee_id].to_s != NONE
+    params[:assignee_id].present?
   end
   def assignee_username?
-    params[:assignee_username].present? && params[:assignee_username].to_s != NONE
+    params[:assignee_username].present?
   end
-  def no_assignee?
+  def filter_by_no_assignee?
     # Assignee_id takes precedence over assignee_username
-    params[:assignee_id].to_s == NONE || params[:assignee_username].to_s == NONE
+    [NONE, FILTER_NONE].include?(params[:assignee_id].to_s) || params[:assignee_username].to_s == NONE
+  end
+
+  def filter_by_any_assignee?
+    params[:assignee_id].to_s == FILTER_ANY
   end
   # rubocop: disable CodeReuse/ActiveRecord
@@ -399,15 +408,17 @@ class IssuableFinder
   # rubocop: disable CodeReuse/ActiveRecord
   def by_assignee(items)
-    if assignee
-      items = items.where(assignee_id: assignee.id)
-    elsif no_assignee?
-      items = items.where(assignee_id: nil)
+    if filter_by_no_assignee?
+      items.where(assignee_id: nil)
+    elsif filter_by_any_assignee?
+      items.where('assignee_id IS NOT NULL')
+    elsif assignee
+      items.where(assignee_id: assignee.id)
     elsif assignee_id? || assignee_username? # assignee not found
-      items = items.none
+      items.none
+    else
+      items
     end
-
-    items
   end
   # rubocop: enable CodeReuse/ActiveRecord

app/finders/issues_finder.rb

@@ -135,12 +135,13 @@ class IssuesFinder < IssuableFinder
     current_user.blank?
   end
-  # rubocop: disable CodeReuse/ActiveRecord
   def by_assignee(items)
-    if assignee
-      items.assigned_to(assignee)
-    elsif no_assignee?
+    if filter_by_no_assignee?
       items.unassigned
+    elsif filter_by_any_assignee?
+      items.assigned
+    elsif assignee
+      items.assigned_to(assignee)
     elsif assignee_id? || assignee_username? # assignee not found
       items.none
     else

lib/api/issues.rb

@@ -40,7 +40,11 @@ module API
         optional :updated_after, type: DateTime, desc: 'Return issues updated after the specified time'
         optional :updated_before, type: DateTime, desc: 'Return issues updated before the specified time'
         optional :author_id, type: Integer, desc: 'Return issues which are authored by the user with the given ID'
-        optional :assignee_id, type: Integer, desc: 'Return issues which are assigned to the user with the given ID'
+        optional :assignee_id, types: [Integer, String],
+                               values: -> (v) {
+                                 v.is_a?(Integer) or [IssuableFinder::FILTER_NONE, IssuableFinder::FILTER_ANY].include?(v)
+                               },
+                               desc: 'Return issues which are assigned to the user with the given ID'
         optional :scope, type: String, values: %w[created-by-me assigned-to-me created_by_me assigned_to_me all],
                          desc: 'Return issues for the given scope: `created_by_me`, `assigned_to_me` or `all`'
         optional :my_reaction_emoji, type: String, desc: 'Return issues reacted by the authenticated user by the given emoji'

spec/finders/issues_finder_spec.rb

@@ -59,11 +59,27 @@ describe IssuesFinder do
       context 'filtering by no assignee' do
         let(:params) { { assignee_id: 0 } }
-        it 'returns issues not assign to any assignee' do
+        it 'returns issues not assigned to any assignee' do
           expect(issues).to contain_exactly(issue4)
         end
       end
+      context 'filtering by no assignee' do
+        let(:params) { { assignee_id: 'None' } }
+
+        it 'returns issues not assigned to any assignee' do
+          expect(issues).to contain_exactly(issue4)
+        end
+      end
+
+      context 'filtering by any assignee' do
+        let(:params) { { assignee_id: 'Any' } }
+
+        it 'returns issues assigned to any assignee' do
+          expect(issues).to contain_exactly(issue1, issue2, issue3)
+        end
+      end
+
       context 'filtering by group_id' do
         let(:params) { { group_id: group.id } }

spec/requests/api/issues_spec.rb

@@ -178,6 +178,21 @@ describe API::Issues do
         expect(first_issue['id']).to eq(issue2.id)
       end
+      it 'returns issues with no assignee' do
+        issue2 = create(:issue, author: user2, project: project)
+
+        get api('/issues', user), assignee_id: 'None', scope: 'all'
+
+        expect_paginated_array_response(size: 1)
+        expect(first_issue['id']).to eq(issue2.id)
+      end
+
+      it 'returns issues with any assignee' do
+        get api('/issues', user), assignee_id: 'Any', scope: 'all'
+
+        expect_paginated_array_response(size: 3)
+      end
+
       it 'returns issues reacted by the authenticated user by the given emoji' do
         issue2 = create(:issue, project: project, author: user, assignees: [user])
         award_emoji = create(:award_emoji, awardable: issue2, user: user2, name: 'star')