Added queries for release filter in issue search

Added new scopes related to issues and releases.
Updated IssuableFinder with use of new scopes.

app/finders/issuable_finder.rb

@@ -13,6 +13,7 @@
 #     group_id: integer
 #     project_id: integer
 #     milestone_title: string
+#     release_tag: string
 #     author_id: integer
 #     author_username: string
 #     assignee_id: integer or 'None' or 'Any'
@@ -59,6 +60,7 @@ class IssuableFinder
       author_username
       label_name
       milestone_title
+      release_tag
       my_reaction_emoji
       search
       in
@@ -126,6 +128,7 @@ class IssuableFinder
     items = by_non_archived(items)
     items = by_iids(items)
     items = by_milestone(items)
+    items = by_release(items)
     items = by_label(items)
     by_my_reaction_emoji(items)
   end
@@ -364,6 +367,10 @@ class IssuableFinder
     end
   end
 
+  def releases?
+    params[:release_tag].present?
+  end
+
   private
 
   def force_cte?
@@ -570,6 +577,20 @@ class IssuableFinder
   end
   # rubocop: enable CodeReuse/ActiveRecord
 
+  def by_release(items)
+    if releases?
+      items = if filter_by_no_release?
+                items.left_joins_milestones_joins_no_release
+              elsif filter_by_any_release?
+                items.left_joins_milestones_joins_releases
+              else
+                items.with_release(params[:release_tag])
+              end
+    end
+
+    items
+  end
+
   def filter_by_no_milestone?
     # Accepts `No Milestone` for compatibility
     params[:milestone_title].to_s.downcase == FILTER_NONE || params[:milestone_title] == Milestone::None.title
@@ -588,6 +609,14 @@ class IssuableFinder
     params[:milestone_title] == Milestone::Started.name
   end
 
+  def filter_by_no_release?
+    params[:release_tag].to_s.downcase == FILTER_NONE
+  end
+
+  def filter_by_any_release?
+    params[:release_tag].to_s.downcase == FILTER_ANY
+  end
+
   def by_label(items)
     return items unless labels?
 

app/finders/merge_requests_finder.rb

@@ -12,6 +12,7 @@
 #     group_id: integer
 #     project_id: integer
 #     milestone_title: string
+#     release_tag: string
 #     author_id: integer
 #     assignee_id: integer
 #     search: string

app/models/concerns/issuable.rb

@@ -100,6 +100,8 @@ module Issuable
     scope :of_milestones, ->(ids) { where(milestone_id: ids) }
     scope :any_milestone, -> { where('milestone_id IS NOT NULL') }
     scope :with_milestone, ->(title) { left_joins_milestones.where(milestones: { title: title }) }
+    scope :any_release, -> { left_joins_milestones_joins_releases }
+    scope :with_release, -> (tag) { left_joins_milestones_joins_releases.where( milestones: { releases: { tag: tag } } ) }
     scope :opened, -> { with_state(:opened) }
     scope :only_opened, -> { with_state(:opened) }
     scope :closed, -> { with_state(:closed) }
@@ -121,6 +123,22 @@ module Issuable
     scope :order_milestone_due_desc, -> { left_joins_milestones.reorder(Arel.sql('milestones.due_date IS NULL, milestones.id IS NULL, milestones.due_date DESC')) }
     scope :order_milestone_due_asc,  -> { left_joins_milestones.reorder(Arel.sql('milestones.due_date IS NULL, milestones.id IS NULL, milestones.due_date ASC')) }
 
+    scope :left_joins_milestones_joins_no_release, -> do
+      joins("LEFT OUTER JOIN milestones
+               LEFT OUTER JOIN milestone_releases ON milestones.id = milestone_releases.milestone_id
+            ON #{table_name}.milestone_id = milestones.id"
+           ).where('milestone_releases.release_id IS NULL')
+    end
+
+    scope :left_joins_milestones_joins_releases, -> do
+      joins("LEFT OUTER JOIN milestones
+              JOIN milestone_releases
+                JOIN releases ON milestone_releases.release_id = releases.id
+              ON milestones.id = milestone_releases.milestone_id
+            ON #{table_name}.milestone_id = milestones.id"
+           ).where('milestone_releases.release_id IS NOT NULL').distinct
+    end
+
     scope :without_label, -> { joins("LEFT OUTER JOIN label_links ON label_links.target_type = '#{name}' AND label_links.target_id = #{table_name}.id").where(label_links: { id: nil }) }
     scope :any_label, -> { joins(:label_links).group(:id) }
     scope :join_project, -> { joins(:project) }