Merge branch '52384-api-filter-assignee-none-any' into 'master'

Resolve "Filter by `None`/`Any` for assignee_id in issues/mrs API"

Closes #52384

See merge request gitlab-org/gitlab-ce!22598

12 files changed, 183 insertions, 25 deletions

diff --git a/app/finders/issuable_finder.rb b/app/finders/issuable_finder.rb
index 8abfe0c4c17..eb3d2498830 100644
--- a/app/finders/issuable_finder.rb
+++ b/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.downcase) || params[:assignee_username].to_s == NONE
+  end
+
+  def filter_by_any_assignee?
+    params[:assignee_id].to_s.downcase == 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
 
diff --git a/app/finders/issues_finder.rb b/app/finders/issues_finder.rb
index abdc47b9866..cee57a83df4 100644
--- a/app/finders/issues_finder.rb
+++ b/app/finders/issues_finder.rb
@@ -137,10 +137,12 @@ class IssuesFinder < IssuableFinder
 
   # 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
diff --git a/changelogs/unreleased/52384-api-filter-assignee-none-any.yml b/changelogs/unreleased/52384-api-filter-assignee-none-any.yml
new file mode 100644
index 00000000000..9acec04d946
--- /dev/null
+++ b/changelogs/unreleased/52384-api-filter-assignee-none-any.yml
@@ -0,0 +1,5 @@
+---
+title: Add None/Any option for assignee_id in Issues and Merge Requests API
+merge_request: 22598
+author: Heinrich Lee Yu
+type: added
diff --git a/doc/api/issues.md b/doc/api/issues.md
index cc1d6834a20..57e861bc62e 100644
--- a/doc/api/issues.md
+++ b/doc/api/issues.md
@@ -40,7 +40,7 @@ GET /issues?my_reaction_emoji=star
 | `milestone`         | string           | no         | The milestone title. `No+Milestone` lists all issues with no milestone. `Any+Milestone` lists all issues that have an assigned milestone            |
 | `scope`             | string           | no         | Return issues for the given scope: `created_by_me`, `assigned_to_me` or `all`. Defaults to `created_by_me`<br> For versions before 11.0, use the now deprecated `created-by-me` or `assigned-to-me` scopes instead.<br> _([Introduced][ce-13004] in GitLab 9.5. [Changed to snake_case][ce-18935] in GitLab 11.0)_ |
 | `author_id`         | integer          | no         | Return issues created by the given user `id`. Combine with `scope=all` or `scope=assigned_to_me`. _([Introduced][ce-13004] in GitLab 9.5)_          |
-| `assignee_id`       | integer          | no         | Return issues assigned to the given user `id` _([Introduced][ce-13004] in GitLab 9.5)_                                                              |
+| `assignee_id`       | integer          | no         | Return issues assigned to the given user `id`. `None` returns unassigned issues. `Any` returns issues with an assignee. _([Introduced][ce-13004] in GitLab 9.5)_ |
 | `my_reaction_emoji` | string           | no         | Return issues reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_                                      |
 | `iids[]`            | Array[integer]   | no         | Return only the issues having the given `iid`                                                                                                       |
 | `order_by`          | string           | no         | Return issues ordered by `created_at` or `updated_at` fields. Default is `created_at`                                                               |
@@ -154,7 +154,7 @@ GET /groups/:id/issues?my_reaction_emoji=star
 | `milestone`         | string           | no         | The milestone title. `No+Milestone` lists all issues with no milestone                                                                                                           |
 | `scope`             | string           | no         | Return issues for the given scope: `created_by_me`, `assigned_to_me` or `all`.<br> For versions before 11.0, use the now deprecated `created-by-me` or `assigned-to-me` scopes instead.<br> _([Introduced][ce-13004] in GitLab 9.5. [Changed to snake_case][ce-18935] in GitLab 11.0)_ |
 | `author_id`         | integer          | no         | Return issues created by the given user `id` _([Introduced][ce-13004] in GitLab 9.5)_                                         |
-| `assignee_id`       | integer          | no         | Return issues assigned to the given user `id` _([Introduced][ce-13004] in GitLab 9.5)_                                        |
+| `assignee_id`       | integer          | no         | Return issues assigned to the given user `id`. `None` returns unassigned issues. `Any` returns issues with an assignee. _([Introduced][ce-13004] in GitLab 9.5)_ |
 | `my_reaction_emoji` | string           | no         | Return issues reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_                |
 | `order_by`          | string           | no         | Return issues ordered by `created_at` or `updated_at` fields. Default is `created_at`                                         |
 | `sort`              | string           | no         | Return issues sorted in `asc` or `desc` order. Default is `desc`                                                              |
@@ -268,7 +268,7 @@ GET /projects/:id/issues?my_reaction_emoji=star
 | `milestone`         | string           | no         | The milestone title. `No+Milestone` lists all issues with no milestone                                                                                                           |
 | `scope`             | string           | no         | Return issues for the given scope: `created_by_me`, `assigned_to_me` or `all`.<br> For versions before 11.0, use the now deprecated `created-by-me` or `assigned-to-me` scopes instead.<br> _([Introduced][ce-13004] in GitLab 9.5. [Changed to snake_case][ce-18935] in GitLab 11.0)_ |
 | `author_id`         | integer          | no         | Return issues created by the given user `id` _([Introduced][ce-13004] in GitLab 9.5)_                                         |
-| `assignee_id`       | integer          | no         | Return issues assigned to the given user `id` _([Introduced][ce-13004] in GitLab 9.5)_                                        |
+| `assignee_id`       | integer          | no         | Return issues assigned to the given user `id`. `None` returns unassigned issues. `Any` returns issues with an assignee. _([Introduced][ce-13004] in GitLab 9.5)_ |
 | `my_reaction_emoji` | string           | no         | Return issues reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_                |
 | `order_by`          | string           | no         | Return issues ordered by `created_at` or `updated_at` fields. Default is `created_at`                                         |
 | `sort`              | string           | no         | Return issues sorted in `asc` or `desc` order. Default is `desc`                                                              |
diff --git a/doc/api/merge_requests.md b/doc/api/merge_requests.md
index 862ee398a84..0291b7e00c2 100644
--- a/doc/api/merge_requests.md
+++ b/doc/api/merge_requests.md
@@ -42,7 +42,7 @@ Parameters:
 | `updated_before`    | datetime | no       | Return merge requests updated on or before the given time                                                              |
 | `scope`             | string   | no       | Return merge requests for the given scope: `created_by_me`, `assigned_to_me` or `all`. Defaults to `created_by_me`<br> For versions before 11.0, use the now deprecated `created-by-me` or `assigned-to-me` scopes instead. |
 | `author_id`         | integer  | no       | Returns merge requests created by the given user `id`. Combine with `scope=all` or `scope=assigned_to_me`              |
-| `assignee_id`       | integer  | no       | Returns merge requests assigned to the given user `id`                                                                 |
+| `assignee_id`       | integer  | no       | Returns merge requests assigned to the given user `id`. `None` returns unassigned merge requests. `Any` returns merge requests with an assignee. |
 | `my_reaction_emoji` | string   | no       | Return merge requests reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_ |
 | `source_branch`     | string   | no       | Return merge requests with the given source branch                                                                     |
 | `target_branch`     | string   | no       | Return merge requests with the given target branch                                                                     |
@@ -166,7 +166,7 @@ Parameters:
 | `updated_before`    | datetime       | no       | Return merge requests updated on or before the given time                                                                      |
 | `scope`             | string         | no       | Return merge requests for the given scope: `created_by_me`, `assigned_to_me` or `all`.<br> For versions before 11.0, use the now deprecated `created-by-me` or `assigned-to-me` scopes instead.<br> _([Introduced][ce-13060] in GitLab 9.5. [Changed to snake_case][ce-18935] in GitLab 11.0)_ |
 | `author_id`         | integer        | no       | Returns merge requests created by the given user `id` _([Introduced][ce-13060] in GitLab 9.5)_                                 |
-| `assignee_id`       | integer        | no       | Returns merge requests assigned to the given user `id` _([Introduced][ce-13060] in GitLab 9.5)_                                |
+| `assignee_id`       | integer        | no       | Returns merge requests assigned to the given user `id`. `None` returns unassigned merge requests. `Any` returns merge requests with an assignee. _([Introduced][ce-13060] in GitLab 9.5)_ |
 | `my_reaction_emoji` | string         | no       | Return merge requests reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_         |
 | `source_branch`     | string   | no       | Return merge requests with the given source branch                                                                     |
 | `target_branch`     | string   | no       | Return merge requests with the given target branch                                                                     |
@@ -279,7 +279,7 @@ Parameters:
 | `updated_before`    | datetime       | no       | Return merge requests updated on or before the given time                                                                      |
 | `scope`             | string         | no       | Return merge requests for the given scope: `created_by_me`, `assigned_to_me` or `all`.<br>                                     |
 | `author_id`         | integer        | no       | Returns merge requests created by the given user `id` _([Introduced][ce-13060] in GitLab 9.5)_                                 |
-| `assignee_id`       | integer        | no       | Returns merge requests assigned to the given user `id` _([Introduced][ce-13060] in GitLab 9.5)_                                |
+| `assignee_id`       | integer        | no       | Returns merge requests assigned to the given user `id`. `None` returns unassigned merge requests. `Any` returns merge requests with an assignee. _([Introduced][ce-13060] in GitLab 9.5)_ |
 | `my_reaction_emoji` | string         | no       | Return merge requests reacted by the authenticated user by the given `emoji` _([Introduced][ce-14016] in GitLab 10.0)_         |
 | `source_branch`     | string   | no       | Return merge requests with the given source branch                                                                     |
 | `target_branch`     | string   | no       | Return merge requests with the given target branch                                                                     |
diff --git a/lib/api/helpers/custom_validators.rb b/lib/api/helpers/custom_validators.rb
index 23b1cd1ad45..1058f4e8a5e 100644
--- a/lib/api/helpers/custom_validators.rb
+++ b/lib/api/helpers/custom_validators.rb
@@ -10,8 +10,21 @@ module API
           raise Grape::Exceptions::Validation, params: [@scope.full_name(attr_name)], message: message(:absence)
         end
       end
+
+      class IntegerNoneAny < Grape::Validations::Base
+        def validate_param!(attr_name, params)
+          value = params[attr_name]
+
+          return if value.is_a?(Integer) ||
+              [IssuableFinder::FILTER_NONE, IssuableFinder::FILTER_ANY].include?(value.to_s.downcase)
+
+          raise Grape::Exceptions::Validation, params: [@scope.full_name(attr_name)],
+                                               message: "should be an integer, 'None' or 'Any'"
+        end
+      end
     end
   end
 end
 
 Grape::Validations.register_validator(:absence, ::API::Helpers::CustomValidators::Absence)
+Grape::Validations.register_validator(:integer_none_any, ::API::Helpers::CustomValidators::IntegerNoneAny)
diff --git a/lib/api/issues.rb b/lib/api/issues.rb
index 25d78053c88..405fc30a2ed 100644
--- a/lib/api/issues.rb
+++ b/lib/api/issues.rb
@@ -40,7 +40,8 @@ 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], integer_none_any: true,
+                               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'
diff --git a/lib/api/merge_requests.rb b/lib/api/merge_requests.rb
index 440d94ae186..a617efaaa4c 100644
--- a/lib/api/merge_requests.rb
+++ b/lib/api/merge_requests.rb
@@ -89,7 +89,8 @@ module API
         optional :updated_before, type: DateTime, desc: 'Return merge requests updated before the specified time'
         optional :view, type: String, values: %w[simple], desc: 'If simple, returns the `iid`, URL, title, description, and basic state of merge request'
         optional :author_id, type: Integer, desc: 'Return merge requests which are authored by the user with the given ID'
-        optional :assignee_id, type: Integer, desc: 'Return merge requests which are assigned to the user with the given ID'
+        optional :assignee_id, types: [Integer, String], integer_none_any: true,
+                               desc: 'Return merge requests 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 merge requests 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'
diff --git a/spec/finders/issues_finder_spec.rb b/spec/finders/issues_finder_spec.rb
index 0689c843104..2f164ffa8b0 100644
--- a/spec/finders/issues_finder_spec.rb
+++ b/spec/finders/issues_finder_spec.rb
@@ -57,11 +57,37 @@ describe IssuesFinder do
       end
 
       context 'filtering by no assignee' do
-        let(:params) { { assignee_id: 0 } }
+        let(:params) { { assignee_id: 'None' } }
 
-        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
+
+        it 'returns issues not assigned to any assignee' do
+          params[:assignee_id] = 0
+
+          expect(issues).to contain_exactly(issue4)
+        end
+
+        it 'returns issues not assigned to any assignee' do
+          params[:assignee_id] = 'none'
+
+          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
+
+        it 'returns issues assigned to any assignee' do
+          params[:assignee_id] = 'any'
+
+          expect(issues).to contain_exactly(issue1, issue2, issue3)
+        end
       end
 
       context 'filtering by group_id' do
diff --git a/spec/lib/api/helpers/custom_validators_spec.rb b/spec/lib/api/helpers/custom_validators_spec.rb
new file mode 100644
index 00000000000..41e6fb47b11
--- /dev/null
+++ b/spec/lib/api/helpers/custom_validators_spec.rb
@@ -0,0 +1,64 @@
+require 'spec_helper'
+
+describe API::Helpers::CustomValidators do
+  let(:scope) do
+    Struct.new(:opts) do
+      def full_name(attr_name)
+        attr_name
+      end
+    end
+  end
+
+  describe API::Helpers::CustomValidators::Absence do
+    subject do
+      described_class.new(['test'], {}, false, scope.new)
+    end
+
+    context 'empty param' do
+      it 'does not raise a validation error' do
+        expect_no_validation_error({})
+      end
+    end
+
+    context 'invalid parameters' do
+      it 'should raise a validation error' do
+        expect_validation_error({ 'test' => 'some_value' })
+      end
+    end
+  end
+
+  describe API::Helpers::CustomValidators::IntegerNoneAny do
+    subject do
+      described_class.new(['test'], {}, false, scope.new)
+    end
+
+    context 'valid parameters' do
+      it 'does not raise a validation error' do
+        expect_no_validation_error({ 'test' => 2 })
+        expect_no_validation_error({ 'test' => 100 })
+        expect_no_validation_error({ 'test' => 'None' })
+        expect_no_validation_error({ 'test' => 'Any' })
+        expect_no_validation_error({ 'test' => 'none' })
+        expect_no_validation_error({ 'test' => 'any' })
+      end
+    end
+
+    context 'invalid parameters' do
+      it 'should raise a validation error' do
+        expect_validation_error({ 'test' => 'some_other_string' })
+      end
+    end
+  end
+
+  def expect_no_validation_error(params)
+    expect { validate_test_param!(params) }.not_to raise_error
+  end
+
+  def expect_validation_error(params)
+    expect { validate_test_param!(params) }.to raise_error(Grape::Exceptions::Validation)
+  end
+
+  def validate_test_param!(params)
+    subject.validate_param!('test', params)
+  end
+end
diff --git a/spec/requests/api/issues_spec.rb b/spec/requests/api/issues_spec.rb
index 9f6cf12f9a7..9cda39a569b 100644
--- a/spec/requests/api/issues_spec.rb
+++ b/spec/requests/api/issues_spec.rb
@@ -178,6 +178,24 @@ 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
+        # This issue without assignee should not be returned
+        create(:issue, author: user2, project: project)
+
+        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')
diff --git a/spec/requests/api/merge_requests_spec.rb b/spec/requests/api/merge_requests_spec.rb
index 07d19e3ad29..e4e0ca285e0 100644
--- a/spec/requests/api/merge_requests_spec.rb
+++ b/spec/requests/api/merge_requests_spec.rb
@@ -143,6 +143,23 @@ describe API::MergeRequests do
         expect_response_ordered_exactly(merge_request3)
       end
 
+      it 'returns an array of merge requests with no assignee' do
+        merge_request3 = create(:merge_request, :simple, author: user, source_project: project2, target_project: project2, source_branch: 'other-branch')
+
+        get api('/merge_requests', user), assignee_id: 'None', scope: :all
+
+        expect_response_ordered_exactly(merge_request3)
+      end
+
+      it 'returns an array of merge requests with any assignee' do
+        # This MR with no assignee should not be returned
+        create(:merge_request, :simple, author: user, source_project: project2, target_project: project2, source_branch: 'other-branch')
+
+        get api('/merge_requests', user), assignee_id: 'Any', scope: :all
+
+        expect_response_contain_exactly(merge_request, merge_request2, merge_request_closed, merge_request_merged, merge_request_locked)
+      end
+
       it 'returns an array of merge requests assigned to me' do
         merge_request3 = create(:merge_request, :simple, author: user, assignee: user2, source_project: project2, target_project: project2, source_branch: 'other-branch')