limit creation of file_links to 20 at once

docs/api/apiv3/paths/work_package_file_links.yml

@@ -11,10 +11,10 @@ post:
 
     The request body must contain the generated storage token, and not the storage id. In addition, the request must
     send the origin file id and the stored meta data.
-    
-    If there is already a link on the given work package with the same file id from the same storage, the previous
-    data is not overwritten.
-    
+
+    Up to 20 file links can be submitted at once. If there is already a link on the given work package with the same
+    file id from the same storage, the previous data is not overwritten.
+
     As it is possible to link folders from a storage to a work package, the _mimeType_ of this entity can be empty.
   parameters:
     - name: id
@@ -44,7 +44,7 @@ post:
                 _links:
                   storageUrl:
                     href: https://nextcloud.deathstar.rocks/
-  
+
   responses:
     '201':
       description: Created
@@ -137,9 +137,9 @@ get:
             message: You are not authorized to access this resource.
       description: |-
         Returned if the client does not have sufficient permissions.
-        
+
         **Required permission:** view file links
-        
+
         *Note that you will only receive this error, if you are at least allowed to see the corresponding work package.*
     '404':
       content:

lib/api/utilities/endpoints/bodied.rb

@@ -84,7 +84,7 @@ module API
           endpoint = self
 
           -> do
-            request = self # proc is executed in the context of the request
+            request = self # proc is executed in the context of the grape request
             endpoint.before_hook&.(request: request)
             params = endpoint.parse(request)
             call = endpoint.process(request, params)

modules/storages/config/locales/en.yml

@@ -25,6 +25,10 @@ en:
               minimal_nextcloud_version_unmet: "does not meet minimal version requirements (must be Nextcloud 23 or higher)"
               not_nextcloud_server: "is not a Nextcloud server"
 
+  api_v3:
+    errors:
+      too_many_elements_created_at_once: "Too many elements created at once. Expected %{max} at most, got %{actual}."
+
   storages:
     page_titles:
       project_settings:

modules/storages/lib/api/v3/file_links/parse_create_params_service.rb

@@ -28,28 +28,58 @@
 
 module API::V3::FileLinks
   class ParseCreateParamsService < ::API::ParseResourceParamsService
+    MAX_ELEMENTS = 20
+
+    attr_reader :request_body
+
     def call(request_body)
+      @request_body = request_body
       ServiceResult.new(
         success: true,
-        result: parse_elements(request_body)
+        result: parse_elements
       )
     end
 
-    def parse_elements(request_body)
-      request_body.dig("_embedded", "elements")
-                  .tap { ensure_valid_elements(_1) }
-                  .map do |params|
+    private
+
+    def parse_elements
+      assert_valid_elements
+
+      elements.map do |element|
         API::V3::FileLinks::FileLinkRepresenter
           .new(Hashie::Mash.new, current_user: current_user)
-          .from_hash(params)
+          .from_hash(element)
       end
     end
 
-    private
+    def elements
+      @elements ||= request_body.dig("_embedded", "elements")
+    end
+
+    def assert_valid_elements
+      assert_elements_is_present
+      assert_elements_is_an_array
+      assert_elements_does_not_exceed_maximum
+    end
+
+    def assert_elements_is_present
+      return if elements.present?
+
+      raise API::Errors::PropertyMissingError.new('_embedded/elements')
+    end
+
+    def assert_elements_is_an_array
+      return if elements.is_a?(Array)
+
+      raise API::Errors::PropertyFormatError.new('_embedded/elements', 'Array', elements.class.name)
+    end
+
+    def assert_elements_does_not_exceed_maximum
+      return if elements.size <= MAX_ELEMENTS
 
-    def ensure_valid_elements(elements)
-      raise API::Errors::PropertyMissingError.new('_embedded/elements') if elements.blank?
-      raise API::Errors::PropertyFormatError.new('_embedded/elements', 'Array', elements.class.name) unless elements.is_a?(Array)
+      raise API::Errors::Validation.new('_embedded/elements',
+                                        I18n.t('api_v3.errors.too_many_elements_created_at_once',
+                                               max: MAX_ELEMENTS, actual: elements.size))
     end
   end
 end

modules/storages/spec/requests/api/v3/file_links/file_links_spec.rb

@@ -183,6 +183,42 @@ describe 'API v3 file links resource', type: :request do
                              expected_format: 'Array',
                              actual: 'Integer')
     end
+
+    # rubocop:disable RSpec/MultipleMemoizedHelpers
+    context "when more than #{API::V3::FileLinks::ParseCreateParamsService::MAX_ELEMENTS} embedded elements" do
+      let(:max) { API::V3::FileLinks::ParseCreateParamsService::MAX_ELEMENTS }
+      let(:too_many) { max + 1 }
+      let(:params) do
+        {
+          _type: "Collection",
+          _embedded: {
+            elements: 1.upto(too_many).map do |id|
+              {
+                originData: {
+                  id: id,
+                  name: "logo#{id}.png",
+                  mimeType: "image/png",
+                  createdAt: "2021-12-19T09:42:10.170Z",
+                  lastModifiedAt: "2021-12-20T14:00:13.987Z",
+                  createdByName: "Luke Skywalker",
+                  lastModifiedByName: "Anakin Skywalker"
+                },
+                _links: {
+                  storageUrl: {
+                    href: storage_url1
+                  }
+                }
+              }
+            end
+          }
+        }
+      end
+
+      it_behaves_like 'constraint violation' do
+        let(:message) { "Too many elements created at once. Expected #{max} at most, got #{too_many}." }
+      end
+    end
+    # rubocop:enable RSpec/MultipleMemoizedHelpers
   end
 
   describe 'GET /api/v3/file_links/:file_link_id' do