Filter by `None`/`Any` for labels in issues/mrs API52371-filter-by-none-any-for-labels-in-issues-mrs-api

By using the parameters `?labels=None|Any` the user can filter
issues/mrs from the API that has `none/any` label.

Affected endpoints are:

- /api/issues
- /api/projects/:id/issues
- /api/groups/:id/issues
- /api/merge_requests
- /api/projects/:id/merge_requests
- /api/groups/:id/merge_requests

9 files changed, 155 insertions, 51 deletions

diff --git a/app/finders/issuable_finder.rb b/app/finders/issuable_finder.rb
index fdc630cbf72..e04e3a2a7e0 100644
--- a/app/finders/issuable_finder.rb
+++ b/app/finders/issuable_finder.rb
@@ -210,7 +210,14 @@ class IssuableFinder
   end
 
   def filter_by_no_label?
-    labels? && params[:label_name].include?(Label::None.title)
+    downcased = label_names.map(&:downcase)
+
+    # Label::NONE is deprecated and should be removed in 12.0
+    downcased.include?(FILTER_NONE) || downcased.include?(Label::NONE)
+  end
+
+  def filter_by_any_label?
+    label_names.map(&:downcase).include?(FILTER_ANY)
   end
 
   def labels
@@ -465,6 +472,8 @@ class IssuableFinder
     items =
       if filter_by_no_label?
         items.without_label
+      elsif filter_by_any_label?
+        items.any_label
       else
         items.with_label(label_names, params[:sort])
       end
diff --git a/app/models/concerns/issuable.rb b/app/models/concerns/issuable.rb
index 69c5affe142..5080fe03cc8 100644
--- a/app/models/concerns/issuable.rb
+++ b/app/models/concerns/issuable.rb
@@ -90,6 +90,7 @@ module Issuable
     scope :order_milestone_due_asc,  -> { left_joins_milestones.reorder('milestones.due_date IS NULL, milestones.id IS NULL, milestones.due_date ASC') }
 
     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) }
     scope :inc_notes_with_associations, -> { includes(notes: [:project, :author, :award_emoji]) }
     scope :references_project, -> { references(:project) }
diff --git a/app/models/label.rb b/app/models/label.rb
index 165e4a8f3e5..5d2d1afd1d9 100644
--- a/app/models/label.rb
+++ b/app/models/label.rb
@@ -9,15 +9,10 @@ class Label < ActiveRecord::Base
   include Sortable
   include FromUnion
 
-  # Represents a "No Label" state used for filtering Issues and Merge
-  # Requests that have no label assigned.
-  LabelStruct = Struct.new(:title, :name)
-  None = LabelStruct.new('No Label', 'No Label')
-  Any = LabelStruct.new('Any Label', '')
-
   cache_markdown_field :description, pipeline: :single_line
 
-  DEFAULT_COLOR = '#428BCA'.freeze
+  DEFAULT_COLOR = '#428BCA'
+  NONE = 'no label'
 
   default_value_for :color, DEFAULT_COLOR
 
diff --git a/changelogs/unreleased/52371-filter-by-none-any-for-labels-in-issues-mrs-api.yml b/changelogs/unreleased/52371-filter-by-none-any-for-labels-in-issues-mrs-api.yml
new file mode 100644
index 00000000000..bb196af3e90
--- /dev/null
+++ b/changelogs/unreleased/52371-filter-by-none-any-for-labels-in-issues-mrs-api.yml
@@ -0,0 +1,5 @@
+---
+title: Filter by None/Any for labels in issues/mrs API
+merge_request: 22622
+author: Jacopo Beschi @jacopo-beschi
+type: added
diff --git a/doc/api/issues.md b/doc/api/issues.md
index 0e97d9ea6f5..9e245f820a3 100644
--- a/doc/api/issues.md
+++ b/doc/api/issues.md
@@ -36,7 +36,7 @@ GET /issues?my_reaction_emoji=star
 | Attribute           | Type             | Required   | Description                                                                                                                                         |
 | ------------------- | ---------------- | ---------- | --------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `state`             | string           | no         | Return all issues or just those that are `opened` or `closed`                                                                                       |
-| `labels`            | string           | no         | Comma-separated list of label names, issues must have all labels to be returned. `No+Label` lists all issues with no labels                         |
+| `labels`            | string           | no         | Comma-separated list of label names, issues must have all labels to be returned. `None` lists all issues with no labels. `Any` lists all issues with at least one label. `No+Label` (Deprecated) lists all issues with no labels. |
 | `milestone`         | string           | no         | The milestone title. `None` lists all issues with no milestone. `Any` 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)_          |
@@ -149,7 +149,7 @@ GET /groups/:id/issues?my_reaction_emoji=star
 | ------------------- | ---------------- | ---------- | ----------------------------------------------------------------------------------------------------------------------------- |
 | `id`                | integer/string   | yes        | The ID or [URL-encoded path of the group](README.md#namespaced-path-encoding) owned by the authenticated user                 |
 | `state`             | string           | no         | Return all issues or just those that are `opened` or `closed`                                                                 |
-| `labels`            | string           | no         | Comma-separated list of label names, issues must have all labels to be returned. `No+Label` lists all issues with no labels   |
+| `labels`            | string           | no         | Comma-separated list of label names, issues must have all labels to be returned. `None` lists all issues with no labels. `Any` lists all issues with at least one label. `No+Label` (Deprecated) lists all issues with no labels. |
 | `iids[]`            | Array[integer]   | no         | Return only the issues having the given `iid`                                                                                 |
 | `milestone`         | string           | no         | The milestone title. `None` lists all issues with no milestone. `Any` 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`.<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)_ |
@@ -264,7 +264,7 @@ GET /projects/:id/issues?my_reaction_emoji=star
 | `id`                | integer/string   | yes        | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user               |
 | `iids[]`            | Array[integer]   | no         | Return only the milestone having the given `iid`                                                                              |
 | `state`             | string           | no         | Return all issues or just those that are `opened` or `closed`                                                                 |
-| `labels`            | string           | no         | Comma-separated list of label names, issues must have all labels to be returned. `No+Label` lists all issues with no labels   |
+| `labels`            | string           | no         | Comma-separated list of label names, issues must have all labels to be returned. `None` lists all issues with no labels. `Any` lists all issues with at least one label. `No+Label` (Deprecated) lists all issues with no labels. |
 | `milestone`         | string           | no         | The milestone title. `None` lists all issues with no milestone. `Any` 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`.<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)_                                         |
diff --git a/doc/api/merge_requests.md b/doc/api/merge_requests.md
index 9cb3f0d9c0c..30b31a04475 100644
--- a/doc/api/merge_requests.md
+++ b/doc/api/merge_requests.md
@@ -35,7 +35,7 @@ Parameters:
 | `sort`              | string   | no       | Return requests sorted in `asc` or `desc` order. Default is `desc`                                                     |
 | `milestone`         | string   | no       | Return merge requests for a specific milestone. `None` returns merge requests with no milestone. `Any` returns merge requests that have an assigned milestone. |
 | `view`              | string   | no       | If `simple`, returns the `iid`, URL, title, description, and basic state of merge request                              |
-| `labels`            | string   | no       | Return merge requests matching a comma separated list of labels                                                        |
+| `labels`            | string   | no       | Return merge requests matching a comma separated list of labels. `None` lists all merge requests with no labels. `Any` lists all merge requests with at least one label. `No+Label` (Deprecated) lists all merge requests with no labels. |
 | `created_after`     | datetime | no       | Return merge requests created on or after the given time                                                               |
 | `created_before`    | datetime | no       | Return merge requests created on or before the given time                                                              |
 | `updated_after`     | datetime | no       | Return merge requests updated on or after the given time                                                               |
@@ -170,7 +170,7 @@ Parameters:
 | `sort`              | string         | no       | Return requests sorted in `asc` or `desc` order. Default is `desc`                                                             |
 | `milestone`         | string         | no       | Return merge requests for a specific milestone. `None` returns merge requests with no milestone. `Any` returns merge requests that have an assigned milestone. |
 | `view`              | string         | no       | If `simple`, returns the `iid`, URL, title, description, and basic state of merge request                                      |
-| `labels`            | string         | no       | Return merge requests matching a comma separated list of labels                                                                |
+| `labels`            | string         | no       | Return merge requests matching a comma separated list of labels. `None` lists all merge requests with no labels. `Any` lists all merge requests with at least one label. `No+Label` (Deprecated) lists all merge requests with no labels. |
 | `created_after`     | datetime       | no       | Return merge requests created on or after the given time                                                                       |
 | `created_before`    | datetime       | no       | Return merge requests created on or before the given time                                                                      |
 | `updated_after`     | datetime       | no       | Return merge requests updated on or after the given time                                                                       |
@@ -294,7 +294,7 @@ Parameters:
 | `sort`              | string         | no       | Return merge requests sorted in `asc` or `desc` order. Default is `desc`                                                       |
 | `milestone`         | string         | no       | Return merge requests for a specific milestone. `None` returns merge requests with no milestone. `Any` returns merge requests that have an assigned milestone. |
 | `view`              | string         | no       | If `simple`, returns the `iid`, URL, title, description, and basic state of merge request                                      |
-| `labels`            | string         | no       | Return merge requests matching a comma separated list of labels                                                                |
+| `labels`            | string         | no       | Return merge requests matching a comma separated list of labels. `None` lists all merge requests with no labels. `Any` lists all merge requests with at least one label. `No+Label` (Deprecated) lists all merge requests with no labels. |
 | `created_after`     | datetime       | no       | Return merge requests created on or after the given time                                                                       |
 | `created_before`    | datetime       | no       | Return merge requests created on or before the given time                                                                      |
 | `updated_after`     | datetime       | no       | Return merge requests updated on or after the given time                                                                       |
diff --git a/spec/finders/issues_finder_spec.rb b/spec/finders/issues_finder_spec.rb
index c0488c83bd8..515f6f70b99 100644
--- a/spec/finders/issues_finder_spec.rb
+++ b/spec/finders/issues_finder_spec.rb
@@ -256,19 +256,51 @@ describe IssuesFinder do
           create(:label_link, label: label2, target: issue2)
         end
 
-        it 'returns the unique issues with any of those labels' do
+        it 'returns the unique issues with all those labels' do
+          expect(issues).to contain_exactly(issue2)
+        end
+      end
+
+      context 'filtering by a label that includes any or none in the title' do
+        let(:params) { { label_name: [label.title, label2.title].join(',') } }
+        let(:label) { create(:label, title: 'any foo', project: project2) }
+        let(:label2) { create(:label, title: 'bar none', project: project2) }
+
+        it 'returns the unique issues with all those labels' do
+          create(:label_link, label: label2, target: issue2)
+
           expect(issues).to contain_exactly(issue2)
         end
       end
 
       context 'filtering by no label' do
-        let(:params) { { label_name: Label::None.title } }
+        let(:params) { { label_name: described_class::FILTER_NONE } }
 
         it 'returns issues with no labels' do
           expect(issues).to contain_exactly(issue1, issue3, issue4)
         end
       end
 
+      context 'filtering by legacy No+Label' do
+        let(:params) { { label_name: Label::NONE } }
+
+        it 'returns issues with no labels' do
+          expect(issues).to contain_exactly(issue1, issue3, issue4)
+        end
+      end
+
+      context 'filtering by any label' do
+        let(:params) { { label_name: described_class::FILTER_ANY } }
+
+        it 'returns issues that have one or more label' do
+          2.times do
+            create(:label_link, label: create(:label, project: project2), target: issue3)
+          end
+
+          expect(issues).to contain_exactly(issue2, issue3)
+        end
+      end
+
       context 'filtering by issue term' do
         let(:params) { { search: 'git' } }
 
diff --git a/spec/requests/api/issues_spec.rb b/spec/requests/api/issues_spec.rb
index 3d532dd83c7..1827da61e2d 100644
--- a/spec/requests/api/issues_spec.rb
+++ b/spec/requests/api/issues_spec.rb
@@ -300,17 +300,31 @@ describe API::Issues do
         expect(json_response.first['state']).to eq('opened')
       end
 
-      it 'returns unlabeled issues for "No Label" label' do
-        get api("/issues", user), labels: 'No Label'
+      it 'returns an empty array if no issue matches labels and state filters' do
+        get api("/issues", user), labels: label.title, state: :closed
+
+        expect_paginated_array_response(size: 0)
+      end
+
+      it 'returns an array of issues with any label' do
+        get api("/issues", user), labels: IssuesFinder::FILTER_ANY
 
         expect_paginated_array_response(size: 1)
-        expect(json_response.first['labels']).to be_empty
+        expect(json_response.first['id']).to eq(issue.id)
       end
 
-      it 'returns an empty array if no issue matches labels and state filters' do
-        get api("/issues?labels=#{label.title}&state=closed", user)
+      it 'returns an array of issues with no label' do
+        get api("/issues", user), labels: IssuesFinder::FILTER_NONE
 
-        expect_paginated_array_response(size: 0)
+        expect_paginated_array_response(size: 1)
+        expect(json_response.first['id']).to eq(closed_issue.id)
+      end
+
+      it 'returns an array of issues with no label when using the legacy No+Label filter' do
+        get api("/issues", user), labels: "No Label"
+
+        expect_paginated_array_response(size: 1)
+        expect(json_response.first['id']).to eq(closed_issue.id)
       end
 
       it 'returns an empty array if no issue matches milestone' do
@@ -492,58 +506,58 @@ describe API::Issues do
       end
 
       it 'returns group issues without confidential issues for non project members' do
-        get api("#{base_url}?state=opened", non_member)
+        get api(base_url, non_member), state: :opened
 
         expect_paginated_array_response(size: 1)
         expect(json_response.first['title']).to eq(group_issue.title)
       end
 
       it 'returns group confidential issues for author' do
-        get api("#{base_url}?state=opened", author)
+        get api(base_url, author), state: :opened
 
         expect_paginated_array_response(size: 2)
       end
 
       it 'returns group confidential issues for assignee' do
-        get api("#{base_url}?state=opened", assignee)
+        get api(base_url, assignee), state: :opened
 
         expect_paginated_array_response(size: 2)
       end
 
       it 'returns group issues with confidential issues for project members' do
-        get api("#{base_url}?state=opened", user)
+        get api(base_url, user), state: :opened
 
         expect_paginated_array_response(size: 2)
       end
 
       it 'returns group confidential issues for admin' do
-        get api("#{base_url}?state=opened", admin)
+        get api(base_url, admin), state: :opened
 
         expect_paginated_array_response(size: 2)
       end
 
       it 'returns an array of labeled group issues' do
-        get api("#{base_url}?labels=#{group_label.title}", user)
+        get api(base_url, user), labels: group_label.title
 
         expect_paginated_array_response(size: 1)
         expect(json_response.first['labels']).to eq([group_label.title])
       end
 
       it 'returns an array of labeled group issues where all labels match' do
-        get api("#{base_url}?labels=#{group_label.title},foo,bar", user)
+        get api(base_url, user), labels: "#{group_label.title},foo,bar"
 
         expect_paginated_array_response(size: 0)
       end
 
       it 'returns issues matching given search string for title' do
-        get api("#{base_url}?search=#{group_issue.title}", user)
+        get api(base_url, user), search: group_issue.title
 
         expect_paginated_array_response(size: 1)
         expect(json_response.first['id']).to eq(group_issue.id)
       end
 
       it 'returns issues matching given search string for description' do
-        get api("#{base_url}?search=#{group_issue.description}", user)
+        get api(base_url, user), search: group_issue.description
 
         expect_paginated_array_response(size: 1)
         expect(json_response.first['id']).to eq(group_issue.id)
@@ -556,7 +570,7 @@ describe API::Issues do
         create(:label_link, label: label_b, target: group_issue)
         create(:label_link, label: label_c, target: group_issue)
 
-        get api("#{base_url}", user), labels: "#{group_label.title},#{label_b.title},#{label_c.title}"
+        get api(base_url, user), labels: "#{group_label.title},#{label_b.title},#{label_c.title}"
 
         expect_paginated_array_response(size: 1)
         expect(json_response.first['labels']).to eq([label_c.title, label_b.title, group_label.title])
@@ -576,40 +590,55 @@ describe API::Issues do
       end
 
       it 'returns an empty array if no group issue matches labels' do
-        get api("#{base_url}?labels=foo,bar", user)
+        get api(base_url, user), labels: 'foo,bar'
 
         expect_paginated_array_response(size: 0)
       end
 
+      it 'returns an array of group issues with any label' do
+        get api(base_url, user), labels: IssuesFinder::FILTER_ANY
+
+        expect_paginated_array_response(size: 1)
+        expect(json_response.first['id']).to eq(group_issue.id)
+      end
+
+      it 'returns an array of group issues with no label' do
+        get api(base_url, user), labels: IssuesFinder::FILTER_NONE
+
+        response_ids = json_response.map { |issue| issue['id'] }
+
+        expect_paginated_array_response(size: 2)
+        expect(response_ids).to contain_exactly(group_closed_issue.id, group_confidential_issue.id)
+      end
+
       it 'returns an empty array if no issue matches milestone' do
-        get api("#{base_url}?milestone=#{group_empty_milestone.title}", user)
+        get api(base_url, user), milestone: group_empty_milestone.title
 
         expect_paginated_array_response(size: 0)
       end
 
       it 'returns an empty array if milestone does not exist' do
-        get api("#{base_url}?milestone=foo", user)
+        get api(base_url, user), milestone: 'foo'
 
         expect_paginated_array_response(size: 0)
       end
 
       it 'returns an array of issues in given milestone' do
-        get api("#{base_url}?state=opened&milestone=#{group_milestone.title}", user)
+        get api(base_url, user), state: :opened, milestone: group_milestone.title
 
         expect_paginated_array_response(size: 1)
         expect(json_response.first['id']).to eq(group_issue.id)
       end
 
       it 'returns an array of issues matching state in milestone' do
-        get api("#{base_url}?milestone=#{group_milestone.title}"\
-                '&state=closed', user)
+        get api(base_url, user), milestone: group_milestone.title, state: :closed
 
         expect_paginated_array_response(size: 1)
         expect(json_response.first['id']).to eq(group_closed_issue.id)
       end
 
       it 'returns an array of issues with no milestone' do
-        get api("#{base_url}?milestone=#{no_milestone_title}", user)
+        get api(base_url, user), milestone: no_milestone_title
 
         expect(response).to have_gitlab_http_status(200)
 
@@ -645,7 +674,7 @@ describe API::Issues do
       end
 
       it 'sorts by updated_at ascending when requested' do
-        get api("#{base_url}?order_by=updated_at&sort=asc", user)
+        get api(base_url, user), order_by: :updated_at, sort: :asc
 
         response_dates = json_response.map { |issue| issue['updated_at'] }
 
@@ -748,7 +777,7 @@ describe API::Issues do
     end
 
     it 'returns an array of labeled project issues' do
-      get api("#{base_url}/issues?labels=#{label.title}", user)
+      get api("#{base_url}/issues", user), labels: label.title
 
       expect_paginated_array_response(size: 1)
       expect(json_response.first['labels']).to eq([label.title])
@@ -800,26 +829,42 @@ describe API::Issues do
       expect_paginated_array_response(size: 0)
     end
 
+    it 'returns an array of project issues with any label' do
+      get api("#{base_url}/issues", user), labels: IssuesFinder::FILTER_ANY
+
+      expect_paginated_array_response(size: 1)
+      expect(json_response.first['id']).to eq(issue.id)
+    end
+
+    it 'returns an array of project issues with no label' do
+      get api("#{base_url}/issues", user), labels: IssuesFinder::FILTER_NONE
+
+      response_ids = json_response.map { |issue| issue['id'] }
+
+      expect_paginated_array_response(size: 2)
+      expect(response_ids).to contain_exactly(closed_issue.id, confidential_issue.id)
+    end
+
     it 'returns an empty array if no project issue matches labels' do
-      get api("#{base_url}/issues?labels=foo,bar", user)
+      get api("#{base_url}/issues", user), labels: 'foo,bar'
 
       expect_paginated_array_response(size: 0)
     end
 
     it 'returns an empty array if no issue matches milestone' do
-      get api("#{base_url}/issues?milestone=#{empty_milestone.title}", user)
+      get api("#{base_url}/issues", user), milestone: empty_milestone.title
 
       expect_paginated_array_response(size: 0)
     end
 
     it 'returns an empty array if milestone does not exist' do
-      get api("#{base_url}/issues?milestone=foo", user)
+      get api("#{base_url}/issues", user), milestone: :foo
 
       expect_paginated_array_response(size: 0)
     end
 
     it 'returns an array of issues in given milestone' do
-      get api("#{base_url}/issues?milestone=#{milestone.title}", user)
+      get api("#{base_url}/issues", user), milestone: milestone.title
 
       expect_paginated_array_response(size: 2)
       expect(json_response.first['id']).to eq(issue.id)
@@ -827,21 +872,21 @@ describe API::Issues do
     end
 
     it 'returns an array of issues matching state in milestone' do
-      get api("#{base_url}/issues?milestone=#{milestone.title}&state=closed", user)
+      get api("#{base_url}/issues", user), milestone: milestone.title, state: :closed
 
       expect_paginated_array_response(size: 1)
       expect(json_response.first['id']).to eq(closed_issue.id)
     end
 
     it 'returns an array of issues with no milestone' do
-      get api("#{base_url}/issues?milestone=#{no_milestone_title}", user)
+      get api("#{base_url}/issues", user), milestone: no_milestone_title
 
       expect_paginated_array_response(size: 1)
       expect(json_response.first['id']).to eq(confidential_issue.id)
     end
 
     it 'returns an array of issues with any milestone' do
-      get api("#{base_url}/issues?milestone=#{any_milestone_title}", user)
+      get api("#{base_url}/issues", user), milestone: any_milestone_title
 
       response_ids = json_response.map { |issue| issue['id'] }
 
@@ -859,7 +904,7 @@ describe API::Issues do
     end
 
     it 'sorts ascending when requested' do
-      get api("#{base_url}/issues?sort=asc", user)
+      get api("#{base_url}/issues", user), sort: :asc
 
       response_dates = json_response.map { |issue| issue['created_at'] }
 
@@ -868,7 +913,7 @@ describe API::Issues do
     end
 
     it 'sorts by updated_at descending when requested' do
-      get api("#{base_url}/issues?order_by=updated_at", user)
+      get api("#{base_url}/issues", user), order_by: :updated_at
 
       response_dates = json_response.map { |issue| issue['updated_at'] }
 
@@ -877,7 +922,7 @@ describe API::Issues do
     end
 
     it 'sorts by updated_at ascending when requested' do
-      get api("#{base_url}/issues?order_by=updated_at&sort=asc", user)
+      get api("#{base_url}/issues", user), order_by: :updated_at, sort: :asc
 
       response_dates = json_response.map { |issue| issue['updated_at'] }
 
diff --git a/spec/support/shared_examples/requests/api/merge_requests_list.rb b/spec/support/shared_examples/requests/api/merge_requests_list.rb
index 668a390b5d2..92d4dd598d5 100644
--- a/spec/support/shared_examples/requests/api/merge_requests_list.rb
+++ b/spec/support/shared_examples/requests/api/merge_requests_list.rb
@@ -186,6 +186,23 @@ shared_examples 'merge requests list' do
       expect(json_response.length).to eq(0)
     end
 
+    it 'returns an array of merge requests with any label when filtering by any label' do
+      get api(endpoint_path, user), labels: IssuesFinder::FILTER_ANY
+
+      expect_paginated_array_response
+      expect(json_response.length).to eq(1)
+      expect(json_response.first['id']).to eq(merge_request.id)
+    end
+
+    it 'returns an array of merge requests without a label when filtering by no label' do
+      get api(endpoint_path, user), labels: IssuesFinder::FILTER_NONE
+
+      response_ids = json_response.map { |merge_request| merge_request['id'] }
+
+      expect_paginated_array_response
+      expect(response_ids).to contain_exactly(merge_request_closed.id, merge_request_merged.id, merge_request_locked.id)
+    end
+
     it 'returns an array of labeled merge requests that are merged for a milestone' do
       bug_label = create(:label, title: 'bug', color: '#FFAABB', project: project)