added error handling in create too

lib/api/v3/work_packages/create_work_packages.rb

@@ -51,13 +51,14 @@ module API
         private
 
         def represent_create_result(result, current_user)
+          work_package = result.result
+
           if result.success?
-            work_package = result.result
             WorkPackages::WorkPackageRepresenter.create(work_package.reload,
                                                         current_user: current_user,
                                                         embed_links: true)
           else
-            fail ::API::Errors::ErrorBase.create_and_merge_errors(result.errors)
+            handle_work_package_errors work_package, result
           end
         end
 

spec/requests/api/v3/work_packages/dependent_errors_spec.rb

@@ -87,8 +87,8 @@ describe 'API v3 Work package resource', type: :request, content_type: :json do
   end
 
   let(:dependent_error_result) do
-    proc do |instance|
-      result = ServiceResult.new(success: true, result: instance.work_package)
+    proc do |instance, _attributes, work_package|
+      result = ServiceResult.new(success: true, result: instance.work_package || work_package)
       dep = parent
       dep.errors.add :base, "invalid", message: "invalid"
 
@@ -146,4 +146,57 @@ describe 'API v3 Work package resource', type: :request, content_type: :json do
       end
     end
   end
+
+  describe '#post' do
+    let(:current_user) { FactoryGirl.create :admin }
+
+    let(:path) { api_v3_paths.work_packages }
+    let(:valid_params) do
+      {
+        _type: 'WorkPackage',
+        lockVersion: 0,
+        _links: {
+          author: { href: "/api/v3/users/#{current_user.id}" },
+          project: { href: "/api/v3/projects/#{project.id}" },
+          status: { href: "/api/v3/statuses/#{status.id}" },
+          priority: { href: "/api/v3/priorities/#{work_package.priority.id}" }
+        }
+      }
+    end
+
+    subject(:response) { last_response }
+
+    shared_context 'post request' do
+      before(:each) do
+        post path, params.to_json, 'CONTENT_TYPE' => 'application/json'
+      end
+    end
+
+    before do
+      allow_any_instance_of(WorkPackages::CreateService).to receive(:create, &dependent_error_result)
+    end
+
+    context 'request' do
+      let(:params) { valid_params.merge(subject: "Test Subject") }
+
+      include_context 'post request'
+
+      it { expect(response.status).to eq(422) }
+
+      it 'should respond with an error' do
+        expected_error = {
+          "_type": "Error",
+          "errorIdentifier": "urn:openproject-org:api:v3:errors:PropertyConstraintViolation",
+          "message": "Error in dependent work package ##{parent.id} #{parent.subject}: invalid",
+          "_embedded": {
+            "details": {
+              "attribute": "base"
+            }
+          }
+        }
+
+        expect(subject.body).to be_json_eql(expected_error.to_json)
+      end
+    end
+  end
 end