Add API for release asset links

Authorize against release not project

lib/api/api.rb

@@ -141,6 +141,7 @@ module API
     mount ::API::ProtectedBranches
     mount ::API::ProtectedTags
     mount ::API::Releases
+    mount ::API::Release::Links
     mount ::API::Repositories
     mount ::API::Runner
     mount ::API::Runners

lib/api/release/link.rb

+# frozen_string_literal: true
+
+module API
+  module Release
+    class Links < Grape::API
+      include PaginationParams
+
+      RELEASE_ENDPOINT_REQUIREMETS = API::NAMESPACE_OR_PROJECT_REQUIREMENTS
+        .merge(tag_name: API::NO_SLASH_URL_PART_REGEX)
+
+      before { error!('404 Not Found', 404) unless Feature.enabled?(:releases_page, user_project) }
+
+      params do
+        requires :id, type: String, desc: 'The ID of a project'
+      end
+      resource 'projects/:id', requirements: API::NAMESPACE_OR_PROJECT_REQUIREMENTS do
+        resource 'releases/:tag_name', requirements: RELEASE_ENDPOINT_REQUIREMETS do
+          resource :assets do
+            desc 'Get a list of links of a release' do
+              detail 'This feature was introduced in GitLab 11.7.'
+              success Entities::Releases::Link
+            end
+            params do
+              use :pagination
+            end
+            get 'links' do
+              authorize! :read_release, release
+
+              present paginate(release.links), with: Entities::Releases::Link
+            end
+
+            desc 'Get a link detail of a release' do
+              detail 'This feature was introduced in GitLab 11.7.'
+              success Entities::Releases::Link
+            end
+            params do
+              requires :link_id, type: String, desc: 'The id of the link'
+            end
+            get 'links/:link_id' do
+              authorize! :read_release, release
+
+              present link, with: Entities::Releases::Link
+            end
+
+            desc 'Create a link of a release' do
+              detail 'This feature was introduced in GitLab 11.7.'
+              success Entities::Releases::Link
+            end
+            params do
+              requires :name, type: String, desc: 'The name of the link'
+              requires :url, type: String, desc: 'The URL of the link'
+            end
+            post 'links' do
+              authorize! :create_release, release
+
+              new_link = release.links.create(declared_params(include_missing: false))
+
+              if new_link.persisted?
+                present new_link, with: Entities::Releases::Link
+              else
+                render_api_error!(result[:message], result[:http_status])
+              end
+            end
+
+            desc 'Update a link of a release' do
+              detail 'This feature was introduced in GitLab 11.7.'
+              success Entities::Releases::Link
+            end
+            params do
+              requires :link_id, type: Integer, desc: 'The id of the link'
+              optional :name, type: String, desc: 'The name of the link'
+              optional :url, type: String, desc: 'The URL of the link'
+              at_least_one_of :name, :url
+            end
+            put 'links/:link_id' do
+              authorize! :update_release, release
+
+              if link.update(declared_params(include_missing: false))
+                present link, with: Entities::Releases::Link
+              else
+                render_api_error!(result[:message], result[:http_status])
+              end
+            end
+
+            desc 'Delete a link of a release' do
+              detail 'This feature was introduced in GitLab 11.7.'
+              success Entities::Releases::Link
+            end
+            params do
+              requires :link_id, type: Integer, desc: 'The id of the link'
+            end
+            put 'links/:link_id' do
+              authorize! :destroy_release, release
+
+              if link.destroy
+                present link, with: Entities::Releases::Link
+              else
+                render_api_error!(result[:message], result[:http_status])
+              end
+            end
+          end
+        end
+      end
+
+      helpers do
+        def release
+          @release ||= user_project.releases.find_by_tag(params[:tag_name])
+        end
+
+        def link
+          @link ||= release.links.find(params[:link_id])
+        end
+      end
+    end
+  end
+end