Merge branch 'new-ff-remaining-crud' into 'master'

Support Version 2 Feature Flags in API POST, PUT, and DELETE

See merge request gitlab-org/gitlab!27026

ee/app/models/operations/feature_flag.rb

@@ -34,7 +34,7 @@ module Operations
     before_create :build_default_scope, if: -> { legacy_flag? && scopes.none? }
 
     accepts_nested_attributes_for :scopes, allow_destroy: true
-    accepts_nested_attributes_for :strategies
+    accepts_nested_attributes_for :strategies, allow_destroy: true
 
     scope :ordered, -> { order(:name) }
 

ee/app/models/operations/feature_flags/strategy.rb

@@ -26,6 +26,8 @@ module Operations
 
       validate :parameters_validations, if: -> { errors[:name].blank? }
 
+      accepts_nested_attributes_for :scopes, allow_destroy: true
+
       private
 
       def parameters_validations

ee/lib/api/feature_flags.rb

@@ -30,9 +30,7 @@ module API
             .new(user_project, current_user, declared_params(include_missing: false))
             .execute
 
-          present paginate(feature_flags),
-            with: EE::API::Entities::FeatureFlag,
-            feature_flags_new_version_enabled: feature_flags_new_version_enabled?
+          present_entity(paginate(feature_flags))
         end
 
         desc 'Create a new feature flag' do
@@ -42,26 +40,39 @@ module API
         params do
           requires :name, type: String, desc: 'The name of feature flag'
           optional :description, type: String, desc: 'The description of the feature flag'
+          optional :version, type: String, desc: 'The version of the feature flag', values: Operations::FeatureFlag.versions.keys
           optional :scopes, type: Array do
             requires :environment_scope, type: String, desc: 'The environment scope of the scope'
             requires :active, type: Boolean, desc: 'Active/inactive of the scope'
             requires :strategies, type: JSON, desc: 'The strategies of the scope'
           end
+          optional :strategies, type: Array do
+            requires :name, type: String, desc: 'The strategy name'
+            requires :parameters, type: JSON, desc: 'The strategy parameters'
+            optional :scopes, type: Array do
+              requires :environment_scope, type: String, desc: 'The environment scope of the scope'
+            end
+          end
         end
         post do
           authorize_create_feature_flag!
 
           attrs = declared_params(include_missing: false)
+
+          ensure_post_version_2_flags_enabled! if attrs[:version] == 'new_version_flag'
+
           rename_key(attrs, :scopes, :scopes_attributes)
+          rename_key(attrs, :strategies, :strategies_attributes)
+          update_value(attrs, :strategies_attributes) do |strategies|
+            strategies.map { |s| rename_key(s, :scopes, :scopes_attributes) }
+          end
 
           result = ::FeatureFlags::CreateService
             .new(user_project, current_user, attrs)
             .execute
 
           if result[:status] == :success
-            present result[:feature_flag],
-              with: EE::API::Entities::FeatureFlag,
-              feature_flags_new_version_enabled: feature_flags_new_version_enabled?
+            present_entity(result[:feature_flag])
           else
             render_api_error!(result[:message], result[:http_status])
           end
@@ -79,9 +90,7 @@ module API
         get do
           authorize_read_feature_flag!
 
-          present feature_flag,
-            with: EE::API::Entities::FeatureFlag,
-            feature_flags_new_version_enabled: feature_flags_new_version_enabled?
+          present_entity(feature_flag)
         end
 
         desc 'Enable a strategy for a feature flag on an environment' do
@@ -94,13 +103,14 @@ module API
         end
         post :enable do
           not_found! unless Feature.enabled?(:feature_flag_api, user_project)
+          render_api_error!('Version 2 flags not supported', :unprocessable_entity) if new_version_flag_present?
 
           result = ::FeatureFlags::EnableService
             .new(user_project, current_user, params).execute
 
           if result[:status] == :success
             status :ok
-            present result[:feature_flag], with: EE::API::Entities::FeatureFlag
+            present_entity(result[:feature_flag])
           else
             render_api_error!(result[:message], result[:http_status])
           end
@@ -116,13 +126,55 @@ module API
         end
         post :disable do
           not_found! unless Feature.enabled?(:feature_flag_api, user_project)
+          render_api_error!('Version 2 flags not supported', :unprocessable_entity) if feature_flag.new_version_flag?
 
           result = ::FeatureFlags::DisableService
             .new(user_project, current_user, params).execute
 
           if result[:status] == :success
             status :ok
-            present result[:feature_flag], with: EE::API::Entities::FeatureFlag
+            present_entity(result[:feature_flag])
+          else
+            render_api_error!(result[:message], result[:http_status])
+          end
+        end
+
+        desc 'Update a feature flag' do
+          detail 'This feature will be introduced in GitLab 13.1 if feature_flags_new_version feature flag is removed'
+          success EE::API::Entities::FeatureFlag
+        end
+        params do
+          optional :description, type: String, desc: 'The description of the feature flag'
+          optional :strategies, type: Array do
+            optional :id, type: Integer, desc: 'The strategy id'
+            optional :name, type: String, desc: 'The strategy type'
+            optional :parameters, type: JSON, desc: 'The strategy parameters'
+            optional :_destroy, type: Boolean, desc: 'Delete the strategy when true'
+            optional :scopes, type: Array do
+              optional :id, type: Integer, desc: 'The environment scope id'
+              optional :environment_scope, type: String, desc: 'The environment scope of the scope'
+              optional :_destroy, type: Boolean, desc: 'Delete the scope when true'
+            end
+          end
+        end
+        put do
+          not_found! unless feature_flags_new_version_enabled?
+          authorize_update_feature_flag!
+          render_api_error!('PUT operations are not supported for legacy feature flags', :unprocessable_entity) if feature_flag.legacy_flag?
+
+          attrs = declared_params(include_missing: false)
+
+          rename_key(attrs, :strategies, :strategies_attributes)
+          update_value(attrs, :strategies_attributes) do |strategies|
+            strategies.map { |s| rename_key(s, :scopes, :scopes_attributes) }
+          end
+
+          result = ::FeatureFlags::UpdateService
+            .new(user_project, current_user, attrs)
+            .execute(feature_flag)
+
+          if result[:status] == :success
+            present_entity(result[:feature_flag])
           else
             render_api_error!(result[:message], result[:http_status])
           end
@@ -140,9 +192,7 @@ module API
             .execute(feature_flag)
 
           if result[:status] == :success
-            present result[:feature_flag],
-              with: EE::API::Entities::FeatureFlag,
-              feature_flags_new_version_enabled: feature_flags_new_version_enabled?
+            present_entity(result[:feature_flag])
           else
             render_api_error!(result[:message], result[:http_status])
           end
@@ -163,18 +213,38 @@ module API
         authorize! :create_feature_flag, user_project
       end
 
+      def authorize_update_feature_flag!
+        authorize! :update_feature_flag, feature_flag
+      end
+
       def authorize_destroy_feature_flag!
         authorize! :destroy_feature_flag, feature_flag
       end
 
+      def present_entity(result)
+        present result,
+          with: EE::API::Entities::FeatureFlag,
+          feature_flags_new_version_enabled: feature_flags_new_version_enabled?
+      end
+
+      def ensure_post_version_2_flags_enabled!
+        unless feature_flags_new_version_enabled?
+          render_api_error!('Version 2 flags are not enabled for this project', :unprocessable_entity)
+        end
+      end
+
       def feature_flag
-        @feature_flag ||= if Feature.enabled?(:feature_flags_new_version, user_project)
+        @feature_flag ||= if feature_flags_new_version_enabled?
                             user_project.operations_feature_flags.find_by_name!(params[:name])
                           else
                             user_project.operations_feature_flags.legacy_flag.find_by_name!(params[:name])
                           end
       end
 
+      def new_version_flag_present?
+        user_project.operations_feature_flags.new_version_flag.find_by_name(params[:name]).present?
+      end
+
       def feature_flags_new_version_enabled?
         Feature.enabled?(:feature_flags_new_version, user_project)
       end
@@ -183,6 +253,11 @@ module API
         hash[new_key] = hash.delete(old_key) if hash.key?(old_key)
         hash
       end
+
+      def update_value(hash, key)
+        hash[key] = yield(hash[key]) if hash.key?(key)
+        hash
+      end
     end
   end
 end

ee/spec/requests/api/feature_flags_spec.rb

@@ -238,6 +238,14 @@ describe API::FeatureFlags do
   end
 
   describe 'POST /projects/:id/feature_flags' do
+    def default_scope
+      {
+        environment_scope: '*',
+        active: false,
+        strategies: [{ name: 'default', parameters: {} }].to_json
+      }
+    end
+
     subject do
       post api("/projects/#{project.id}/feature_flags", user), params: params
     end
@@ -260,6 +268,16 @@ describe API::FeatureFlags do
       expect(feature_flag.description).to eq(params[:description])
     end
 
+    it 'defaults to a version 1 (legacy) feature flag' do
+      subject
+
+      expect(response).to have_gitlab_http_status(:created)
+      expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+
+      feature_flag = project.operations_feature_flags.last
+      expect(feature_flag.version).to eq('legacy_flag')
+    end
+
     it_behaves_like 'check user permission'
 
     it 'returns version' do
@@ -341,12 +359,100 @@ describe API::FeatureFlags do
       end
     end
 
-    def default_scope
-      {
-        environment_scope: '*',
-        active: false,
-        strategies: [{ name: 'default', parameters: {} }].to_json
-      }
+    context 'when creating a version 2 feature flag' do
+      it 'creates a new feature flag' do
+        params = {
+          name: 'new-feature',
+          version: 'new_version_flag'
+        }
+
+        post api("/projects/#{project.id}/feature_flags", user), params: params
+
+        expect(response).to have_gitlab_http_status(:created)
+        expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+
+        feature_flag = project.operations_feature_flags.last
+        expect(feature_flag.name).to eq(params[:name])
+        expect(feature_flag.version).to eq('new_version_flag')
+      end
+
+      it 'creates a new feature flag with strategies' do
+        params = {
+          name: 'new-feature',
+          version: 'new_version_flag',
+          strategies: [{
+            name: 'userWithId',
+            parameters: { 'userIds': 'user1' }
+          }]
+        }
+
+        post api("/projects/#{project.id}/feature_flags", user), params: params
+
+        expect(response).to have_gitlab_http_status(:created)
+        expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+
+        feature_flag = project.operations_feature_flags.last
+        expect(feature_flag.name).to eq(params[:name])
+        expect(feature_flag.version).to eq('new_version_flag')
+        expect(feature_flag.strategies.map { |s| s.slice(:name, :parameters).deep_symbolize_keys }).to eq([{
+          name: 'userWithId',
+          parameters: { userIds: 'user1' }
+        }])
+      end
+
+      it 'creates a new feature flag with strategies with scopes' do
+        params = {
+          name: 'new-feature',
+          version: 'new_version_flag',
+          strategies: [{
+            name: 'gradualRolloutUserId',
+            parameters: { groupId: 'default', percentage: '50' },
+            scopes: [{
+              environment_scope: 'staging'
+            }]
+          }]
+        }
+
+        post api("/projects/#{project.id}/feature_flags", user), params: params
+
+        expect(response).to have_gitlab_http_status(:created)
+        expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+
+        feature_flag = project.operations_feature_flags.last
+        expect(feature_flag.name).to eq(params[:name])
+        expect(feature_flag.version).to eq('new_version_flag')
+        expect(feature_flag.strategies.map { |s| s.slice(:name, :parameters).deep_symbolize_keys }).to eq([{
+          name: 'gradualRolloutUserId',
+          parameters: { groupId: 'default', percentage: '50' }
+        }])
+        expect(feature_flag.strategies.first.scopes.map { |s| s.slice(:environment_scope).deep_symbolize_keys }).to eq([{
+          environment_scope: 'staging'
+        }])
+      end
+
+      it 'returns a 422 when the feature flag is disabled' do
+        stub_feature_flags(feature_flags_new_version: false)
+        params = {
+          name: 'new-feature',
+          version: 'new_version_flag'
+        }
+
+        post api("/projects/#{project.id}/feature_flags", user), params: params
+
+        expect(response).to have_gitlab_http_status(:unprocessable_entity)
+        expect(json_response).to eq({ 'message' => 'Version 2 flags are not enabled for this project' })
+        expect(project.operations_feature_flags.count).to eq(0)
+      end
+    end
+
+    context 'when given invalid parameters' do
+      it 'responds with a 400 when given an invalid version' do
+        params = { name: 'new-feature', version: 'bad_value' }
+
+        post api("/projects/#{project.id}/feature_flags", user), params: params
+
+        expect(response).to have_gitlab_http_status(:bad_request)
+      end
     end
   end
 
@@ -374,6 +480,18 @@ describe API::FeatureFlags do
         expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
         expect(feature_flag.name).to eq(params[:name])
         expect(scope.strategies).to eq([JSON.parse(params[:strategy])])
+        expect(feature_flag.version).to eq('legacy_flag')
+      end
+
+      it 'returns the flag version and strategies in the json response' do
+        subject
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+        expect(json_response.slice('version', 'strategies')).to eq({
+          'version' => 'legacy_flag',
+          'strategies' => []
+        })
       end
 
       it_behaves_like 'check user permission'
@@ -423,6 +541,20 @@ describe API::FeatureFlags do
         end
       end
     end
+
+    context 'with a version 2 flag' do
+      let!(:feature_flag) { create(:operations_feature_flag, :new_version_flag, project: project, name: params[:name]) }
+
+      it 'does not change the flag and returns an unprocessable_entity response' do
+        subject
+
+        expect(response).to have_gitlab_http_status(:unprocessable_entity)
+        expect(json_response).to eq({ 'message' => 'Version 2 flags not supported' })
+        feature_flag.reload
+        expect(feature_flag.scopes).to eq([])
+        expect(feature_flag.strategies).to eq([])
+      end
+    end
   end
 
   describe 'POST /projects/:id/feature_flags/:name/disable' do
@@ -472,6 +604,17 @@ describe API::FeatureFlags do
             .to eq([{ name: 'userWithId', parameters: { userIds: 'Project:2' } }.deep_stringify_keys])
         end
 
+        it 'returns the flag version and strategies in the json response' do
+          subject
+
+          expect(response).to have_gitlab_http_status(:ok)
+          expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+          expect(json_response.slice('version', 'strategies')).to eq({
+            'version' => 'legacy_flag',
+            'strategies' => []
+          })
+        end
+
         it_behaves_like 'check user permission'
 
         context 'when strategies become empty array after the removal' do
@@ -501,6 +644,268 @@ describe API::FeatureFlags do
         it_behaves_like 'not found'
       end
     end
+
+    context 'with a version 2 feature flag' do
+      let!(:feature_flag) { create(:operations_feature_flag, :new_version_flag, project: project, name: params[:name]) }
+
+      it 'does not change the flag and returns an unprocessable_entity response' do
+        subject
+
+        expect(response).to have_gitlab_http_status(:unprocessable_entity)
+        expect(json_response).to eq({ 'message' => 'Version 2 flags not supported' })
+        feature_flag.reload
+        expect(feature_flag.scopes).to eq([])
+        expect(feature_flag.strategies).to eq([])
+      end
+    end
+  end
+
+  describe 'PUT /projects/:id/feature_flags/:name' do
+    context 'with a legacy feature flag' do
+      let!(:feature_flag) do
+        create(:operations_feature_flag, :legacy_flag, project: project,
+               name: 'feature1', description: 'old description')
+      end
+
+      it 'returns a 404 if the feature is disabled' do
+        stub_feature_flags(feature_flags_new_version: false)
+        params = { description: 'new description' }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", user), params: params
+
+        expect(response).to have_gitlab_http_status(:not_found)
+        expect(feature_flag.reload.description).to eq('old description')
+      end
+
+      it 'returns a 422' do
+        params = { description: 'new description' }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", user), params: params
+
+        expect(response).to have_gitlab_http_status(:unprocessable_entity)
+        expect(json_response).to eq({ 'message' => 'PUT operations are not supported for legacy feature flags' })
+        expect(feature_flag.reload.description).to eq('old description')
+      end
+    end
+
+    context 'with a version 2 feature flag' do
+      let!(:feature_flag) do
+        create(:operations_feature_flag, :new_version_flag, project: project,
+               name: 'feature1', description: 'old description')
+      end
+
+      it 'returns a 404 if the feature is disabled' do
+        stub_feature_flags(feature_flags_new_version: false)
+        params = { description: 'new description' }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", user), params: params
+
+        expect(response).to have_gitlab_http_status(:not_found)
+        expect(feature_flag.reload.description).to eq('old description')
+      end
+
+      it 'returns a 404 if the feature flag does not exist' do
+        params = { description: 'new description' }
+
+        put api("/projects/#{project.id}/feature_flags/other_flag_name", user), params: params
+
+        expect(response).to have_gitlab_http_status(:not_found)
+        expect(feature_flag.reload.description).to eq('old description')
+      end
+
+      it 'forbids a request for a reporter' do
+        params = { description: 'new description' }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", reporter), params: params
+
+        expect(response).to have_gitlab_http_status(:forbidden)
+        expect(feature_flag.reload.description).to eq('old description')
+      end
+
+      it 'returns an error for an invalid update' do
+        strategy = create(:operations_strategy, feature_flag: feature_flag, name: 'default', parameters: {})
+        params = {
+          strategies: [{
+            id: strategy.id,
+            name: 'gradualRolloutUserId',
+            parameters: { bad: 'params' }
+          }]
+        }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", user), params: params
+
+        expect(response).to have_gitlab_http_status(:bad_request)
+        expect(json_response['message']).not_to be_nil
+        result = feature_flag.reload.strategies.map { |s| s.slice(:id, :name, :parameters).deep_symbolize_keys }
+        expect(result).to eq([{
+          id: strategy.id,
+          name: 'default',
+          parameters: {}
+        }])
+      end
+
+      it 'updates the feature flag' do
+        params = { description: 'new description' }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", user), params: params
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+        expect(feature_flag.reload.description).to eq('new description')
+      end
+
+      it 'ignores a provided version parameter' do
+        params = { description: 'other description', version: 'bad_value' }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", user), params: params
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+        expect(feature_flag.reload.description).to eq('other description')
+      end
+
+      it 'returns the feature flag json' do
+        params = { description: 'new description' }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", user), params: params
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+        feature_flag.reload
+        expect(json_response).to eq({
+          'name' => 'feature1',
+          'description' => 'new description',
+          'created_at' => feature_flag.created_at.as_json,
+          'updated_at' => feature_flag.updated_at.as_json,
+          'scopes' => [],
+          'strategies' => [],
+          'version' => 'new_version_flag'
+        })
+      end
+
+      it 'updates an existing feature flag strategy' do
+        strategy = create(:operations_strategy, feature_flag: feature_flag, name: 'default', parameters: {})
+        params = {
+          strategies: [{
+            id: strategy.id,
+            name: 'gradualRolloutUserId',
+            parameters: { groupId: 'default', percentage: '10' }
+          }]
+        }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", user), params: params
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+        result = feature_flag.reload.strategies.map { |s| s.slice(:id, :name, :parameters).deep_symbolize_keys }
+        expect(result).to eq([{
+          id: strategy.id,
+          name: 'gradualRolloutUserId',
+          parameters: { groupId: 'default', percentage: '10' }
+        }])
+      end
+
+      it 'creates a new feature flag strategy' do
+        strategy = create(:operations_strategy, feature_flag: feature_flag, name: 'default', parameters: {})
+        params = {
+          strategies: [{
+            name: 'gradualRolloutUserId',
+            parameters: { groupId: 'default', percentage: '10' }
+          }]
+        }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", user), params: params
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+        result = feature_flag.reload.strategies
+          .map { |s| s.slice(:id, :name, :parameters).deep_symbolize_keys }
+          .sort_by { |s| s[:name] }
+        expect(result.first[:id]).to eq(strategy.id)
+        expect(result.map { |s| s.slice(:name, :parameters) }).to eq([{
+          name: 'default',
+          parameters: {}
+        }, {
+          name: 'gradualRolloutUserId',
+          parameters: { groupId: 'default', percentage: '10' }
+        }])
+      end
+
+      it 'deletes a feature flag strategy' do
+        strategy_a = create(:operations_strategy, feature_flag: feature_flag, name: 'default', parameters: {})
+        strategy_b = create(:operations_strategy, feature_flag: feature_flag,
+                          name: 'userWithId', parameters: { userIds: 'userA,userB' })
+        params = {
+          strategies: [{
+            id: strategy_a.id,
+            name: 'default',
+            parameters: {},
+            _destroy: true
+          }, {
+            id: strategy_b.id,
+            name: 'userWithId',
+            parameters: { userIds: 'userB' }
+          }]
+        }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", user), params: params
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+        result = feature_flag.reload.strategies
+          .map { |s| s.slice(:id, :name, :parameters).deep_symbolize_keys }
+          .sort_by { |s| s[:name] }
+        expect(result).to eq([{
+          id: strategy_b.id,
+          name: 'userWithId',
+          parameters: { userIds: 'userB' }
+        }])
+      end
+
+      it 'updates an existing feature flag scope' do
+        strategy = create(:operations_strategy, feature_flag: feature_flag, name: 'default', parameters: {})
+        scope = create(:operations_scope, strategy: strategy, environment_scope: '*')
+        params = {
+          strategies: [{
+            id: strategy.id,
+            scopes: [{
+              id: scope.id,
+              environment_scope: 'production'
+            }]
+          }]
+        }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", user), params: params
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+        result = feature_flag.reload.strategies.first.scopes.map { |s| s.slice(:id, :environment_scope).deep_symbolize_keys }
+        expect(result).to eq([{
+          id: scope.id,
+          environment_scope: 'production'
+        }])
+      end
+
+      it 'deletes an existing feature flag scope' do
+        strategy = create(:operations_strategy, feature_flag: feature_flag, name: 'default', parameters: {})
+        scope = create(:operations_scope, strategy: strategy, environment_scope: '*')
+        params = {
+          strategies: [{
+            id: strategy.id,
+            scopes: [{
+              id: scope.id,
+              _destroy: true
+            }]
+          }]
+        }
+
+        put api("/projects/#{project.id}/feature_flags/feature1", user), params: params
+
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(response).to match_response_schema('public_api/v4/feature_flag', dir: 'ee')
+        expect(feature_flag.reload.strategies.first.scopes.count).to eq(0)
+      end
+    end
   end
 
   describe 'DELETE /projects/:id/feature_flags/:name' do
@@ -533,5 +938,23 @@ describe API::FeatureFlags do
       expect(response).to have_gitlab_http_status(:ok)
       expect(json_response.key?('version')).to eq(false)
     end
+
+    context 'with a version 2 feature flag' do
+      let!(:feature_flag) { create(:operations_feature_flag, :new_version_flag, project: project) }
+
+      it 'destroys the flag' do
+        expect { subject }.to change { Operations::FeatureFlag.count }.by(-1)
+
+        expect(response).to have_gitlab_http_status(:ok)
+      end
+
+      it 'returns a 404 if the feature is disabled' do
+        stub_feature_flags(feature_flags_new_version: false)
+
+        expect { subject }.not_to change { Operations::FeatureFlag.count }
+
+        expect(response).to have_gitlab_http_status(:not_found)
+      end
+    end
   end
 end