Add api to lookup epics by reaction emoji

- Add my_reaction_emoji lookup to epics finder
- Add option to epics api and docs
- Migrated epics_finder_spec to use let_it_be

Relates to https://gitlab.com/gitlab-org/gitlab/issues/7783

doc/api/epics.md

@@ -67,6 +67,7 @@ GET /groups/:id/epics?state=opened
 | `updated_before`    | datetime         | no         | Return epics updated on or before the given time                                                                            |
 | `include_ancestor_groups` | boolean    | no         | Include epics from the requested group's ancestors. Default is `false`                                                      |
 | `include_descendant_groups` | boolean  | no         | Include epics from the requested group's descendants. Default is `true`                                                     |
+| `my_reaction_emoji` | string           | no         | Return epics reacted by the authenticated user by the given emoji. `None` returns epics not given a reaction. `Any` returns epics given at least one reaction. Introduced in [GitLab 13.0](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/31479)|
 
 ```shell
 curl --header "PRIVATE-TOKEN: <your_access_token>" https://gitlab.example.com/api/v4/groups/1/epics

ee/app/finders/epics_finder.rb

@@ -34,6 +34,7 @@ class EpicsFinder < IssuableFinder
       start_date
       end_date
       search
+      my_reaction_emoji
     ]
   end
 
@@ -63,6 +64,7 @@ class EpicsFinder < IssuableFinder
     items = by_parent(items)
     items = by_iids(items)
     items = starts_with_iid(items)
+    items = by_my_reaction_emoji(items)
 
     # This has to be last as we use a CTE as an optimization fence
     # for counts by passing the force_cte param and enabling the

ee/changelogs/unreleased-ee/alexives-7783-filter_epics_by_reaction_emoji_in_api.yml

+---
+title: Add my_reaction_emoji param to epics list api
+merge_request: 31479
+author:
+type: added

ee/lib/api/epics.rb

@@ -37,6 +37,7 @@ module API
         optional :updated_before, type: DateTime, desc: 'Return epics updated before the specified time'
         optional :include_ancestor_groups, type: Boolean, default: false, desc: 'Include epics from ancestor groups'
         optional :include_descendant_groups, type: Boolean, default: true, desc: 'Include epics from descendant groups'
+        optional :my_reaction_emoji, type: String, desc: 'Return epics reacted by the authenticated user by the given emoji'
         use :pagination
       end
       get ':id/(-/)epics' do

ee/spec/finders/epics_finder_spec.rb

@@ -3,14 +3,14 @@
 require 'spec_helper'
 
 describe EpicsFinder do
-  let(:user) { create(:user) }
-  let(:search_user) { create(:user) }
-  let(:group) { create(:group, :private) }
-  let(:another_group) { create(:group) }
-  let!(:epic1) { create(:epic, :opened, group: group, title: 'This is awesome epic', created_at: 1.week.ago) }
-  let!(:epic2) { create(:epic, :opened, group: group, created_at: 4.days.ago, author: user, start_date: 2.days.ago, end_date: 3.days.from_now) }
-  let!(:epic3) { create(:epic, :closed, group: group, description: 'not so awesome', start_date: 5.days.ago, end_date: 3.days.ago) }
-  let!(:epic4) { create(:epic, :closed, group: another_group) }
+  let_it_be(:user) { create(:user) }
+  let_it_be(:search_user) { create(:user) }
+  let_it_be(:group) { create(:group, :private) }
+  let_it_be(:another_group) { create(:group) }
+  let_it_be(:epic1) { create(:epic, :opened, group: group, title: 'This is awesome epic', created_at: 1.week.ago) }
+  let_it_be(:epic2) { create(:epic, :opened, group: group, created_at: 4.days.ago, author: user, start_date: 2.days.ago, end_date: 3.days.from_now) }
+  let_it_be(:epic3) { create(:epic, :closed, group: group, description: 'not so awesome', start_date: 5.days.ago, end_date: 3.days.ago) }
+  let_it_be(:epic4) { create(:epic, :closed, group: another_group) }
 
   describe '#execute' do
     def epics(params = {})
@@ -91,6 +91,15 @@ describe EpicsFinder do
           end
         end
 
+        context 'by user reaction emoji' do
+          it 'returns epics reacted to by user' do
+            create(:award_emoji, name: 'thumbsup', awardable: epic1, user: search_user )
+            create(:award_emoji, name: 'star', awardable: epic3, user: search_user )
+
+            expect(epics(my_reaction_emoji: 'star')).to contain_exactly(epic3)
+          end
+        end
+
         context 'by author' do
           it 'returns all epics authored by the given user' do
             expect(epics(author_id: user.id)).to contain_exactly(epic2)
@@ -98,8 +107,8 @@ describe EpicsFinder do
         end
 
         context 'by label' do
-          let(:label) { create(:label) }
-          let!(:labeled_epic) { create(:labeled_epic, group: group, labels: [label]) }
+          let_it_be(:label) { create(:label) }
+          let_it_be(:labeled_epic) { create(:labeled_epic, group: group, labels: [label]) }
 
           it 'returns all epics with given label' do
             expect(epics(label_name: label.title)).to contain_exactly(labeled_epic)
@@ -113,10 +122,10 @@ describe EpicsFinder do
         end
 
         context 'when subgroups are supported' do
-          let(:subgroup) { create(:group, :private, parent: group) }
-          let(:subgroup2) { create(:group, :private, parent: subgroup) }
-          let!(:subgroup_epic) { create(:epic, group: subgroup) }
-          let!(:subgroup2_epic) { create(:epic, group: subgroup2) }
+          let_it_be(:subgroup) { create(:group, :private, parent: group) }
+          let_it_be(:subgroup2) { create(:group, :private, parent: subgroup) }
+          let_it_be(:subgroup_epic) { create(:epic, group: subgroup) }
+          let_it_be(:subgroup2_epic) { create(:epic, group: subgroup2) }
 
           it 'returns all epics that belong to the given group and its subgroups' do
             expect(epics).to contain_exactly(epic1, epic2, epic3, subgroup_epic, subgroup2_epic)
@@ -220,8 +229,8 @@ describe EpicsFinder do
         end
 
         context 'by iids' do
-          let(:subgroup)  { create(:group, :private, parent: group) }
-          let!(:subepic1) { create(:epic, group: subgroup, iid: epic1.iid) }
+          let_it_be(:subgroup) { create(:group, :private, parent: group) }
+          let_it_be(:subepic1) { create(:epic, group: subgroup, iid: epic1.iid) }
 
           it 'returns the specified epics' do
             params = { iids: [epic1.iid, epic2.iid] }
@@ -237,10 +246,10 @@ describe EpicsFinder do
         end
 
         context 'when using iid starts with query' do
-          let!(:epic1) { create(:epic, :opened, group: group, iid: '11') }
-          let!(:epic2) { create(:epic, :opened, group: group, iid: '1112') }
-          let!(:epic3) { create(:epic, :closed, group: group, iid: '9978') }
-          let!(:epic4) { create(:epic, :closed, group: another_group, iid: '111') }
+          let_it_be(:epic1) { create(:epic, :opened, group: group, iid: '11') }
+          let_it_be(:epic2) { create(:epic, :opened, group: group, iid: '1112') }
+          let_it_be(:epic3) { create(:epic, :closed, group: group, iid: '9978') }
+          let_it_be(:epic4) { create(:epic, :closed, group: another_group, iid: '111') }
 
           it 'returns the expected epics if just the first two numbers are given' do
             params = { iid_starts_with: '11' }
@@ -277,7 +286,7 @@ describe EpicsFinder do
           context 'and two labels more search string are present' do
             let_it_be(:label1) { create(:label) }
             let_it_be(:label2) { create(:label) }
-            let!(:labeled_epic) { create(:labeled_epic, group: group, title: 'filtered epic', labels: [label1, label2]) }
+            let_it_be(:labeled_epic) { create(:labeled_epic, group: group, title: 'filtered epic', labels: [label1, label2]) }
 
             it 'returns correct epics' do
               filtered_epics =
@@ -310,10 +319,10 @@ describe EpicsFinder do
   end
 
   describe '#row_count' do
-    let(:label) { create(:label) }
-    let(:label2) { create(:label) }
-    let!(:labeled_epic) { create(:labeled_epic, group: group, labels: [label]) }
-    let!(:labeled_epic2) { create(:labeled_epic, group: group, labels: [label, label2]) }
+    let_it_be(:label) { create(:label) }
+    let_it_be(:label2) { create(:label) }
+    let_it_be(:labeled_epic) { create(:labeled_epic, group: group, labels: [label]) }
+    let_it_be(:labeled_epic2) { create(:labeled_epic, group: group, labels: [label, label2]) }
 
     before do
       group.add_developer(search_user)

ee/spec/requests/api/epics_spec.rb

@@ -3,10 +3,10 @@
 require 'spec_helper'
 
 describe API::Epics do
-  let(:user) { create(:user) }
+  let_it_be(:user) { create(:user) }
   let(:group) { create(:group) }
   let(:project) { create(:project, :public, group: group) }
-  let(:label) { create(:label) }
+  let_it_be(:label) { create(:label) }
   let!(:epic) { create(:labeled_epic, group: group, labels: [label]) }
   let(:params) { nil }
 
@@ -178,6 +178,15 @@ describe API::Epics do
         expect_paginated_array_response([epic2.id])
       end
 
+      it 'returns epics reacted to by current user' do
+        create(:award_emoji, awardable: epic, user: user, name: 'star')
+        create(:award_emoji, awardable: epic2, user: user2, name: 'star')
+
+        get api(url, user), params: { my_reaction_emoji: 'Any', scope: 'all' }
+
+        expect_paginated_array_response([epic.id])
+      end
+
       it 'returns epics matching given search string for title' do
         get api(url), params: { search: epic2.title }