Fixed Import/Export foreign key issue to do with project members

lib/gitlab/import_export/attribute_cleaner.rb

+module Gitlab
+  module ImportExport
+    class AttributeCleaner
+      ALLOWED_REFERENCES = RelationFactory::PROJECT_REFERENCES + RelationFactory::USER_REFERENCES + ['group_id']
+
+      def self.clean(*args)
+        new(*args).clean
+      end
+
+      def initialize(relation_hash:, relation_class:)
+        @relation_hash = relation_hash
+        @relation_class = relation_class
+      end
+
+      def clean
+        @relation_hash.reject do |key, _value|
+          prohibited_key?(key) || !@relation_class.attribute_method?(key)
+        end.except('id')
+      end
+
+      private
+
+      def prohibited_key?(key)
+        key.end_with?('_id') && !ALLOWED_REFERENCES.include?(key)
+      end
+    end
+  end
+end

lib/gitlab/import_export/members_mapper.rb

@@ -55,7 +55,12 @@ module Gitlab
       end
 
       def member_hash(member)
-        member.except('id').merge(source_id: @project.id, importing: true)
+        parsed_hash(member).merge('source_id' => @project.id, 'importing' => true)
+      end
+
+      def parsed_hash(member)
+        Gitlab::ImportExport::AttributeCleaner.clean(relation_hash: member.deep_stringify_keys,
+                                                     relation_class: ProjectMember)
       end
 
       def find_project_user_query(member)

lib/gitlab/import_export/relation_factory.rb

@@ -9,7 +9,7 @@ module Gitlab
                     builds: 'Ci::Build',
                     hooks: 'ProjectHook' }.freeze
 
-      USER_REFERENCES = %w[author_id assignee_id updated_by_id user_id].freeze
+      USER_REFERENCES = %w[author_id assignee_id updated_by_id user_id created_by_id].freeze
 
       BUILD_MODELS = %w[Ci::Build commit_status].freeze
 
@@ -23,7 +23,7 @@ module Gitlab
 
       def initialize(relation_sym:, relation_hash:, members_mapper:, user:)
         @relation_name = OVERRIDES[relation_sym] || relation_sym
-        @relation_hash = relation_hash.except('id', 'noteable_id')
+        @relation_hash = relation_hash.except('noteable_id').merge('project_id' => project_id)
         @members_mapper = members_mapper
         @user = user
         @imported_object_retries = 0
@@ -149,7 +149,8 @@ module Gitlab
       end
 
       def parsed_relation_hash
-        @relation_hash.reject { |k, _v| !relation_class.attribute_method?(k) }
+        @parsed_relation_hash ||= Gitlab::ImportExport::AttributeCleaner.clean(relation_hash: @relation_hash,
+                                                                               relation_class: relation_class)
       end
 
       def set_st_diffs

spec/lib/gitlab/import_export/attribute_cleaner_spec.rb

+require 'spec_helper'
+
+describe Gitlab::ImportExport::AttributeCleaner, lib: true do
+  let(:relation_class){ double('relation_class').as_null_object }
+  let(:unsafe_hash) do
+    {
+      'id' => 101,
+      'service_id' => 99,
+      'moved_to_id' => 99,
+      'namespace_id' => 99,
+      'ci_id' => 99,
+      'random_project_id' => 99,
+      'random_id' => 99,
+      'milestone_id' => 99,
+      'project_id' => 99,
+      'user_id' => 99,
+      'random_id_in_the_middle' => 99,
+      'notid' => 99
+    }
+  end
+
+  let(:post_safe_hash) do
+    {
+      'project_id' => 99,
+      'user_id' => 99,
+      'random_id_in_the_middle' => 99,
+      'notid' => 99
+    }
+  end
+
+  it 'removes unwanted attributes from the hash' do
+    # allow(relation_class).to receive(:attribute_method?).and_return(true)
+    parsed_hash = described_class.clean(relation_hash: unsafe_hash, relation_class: relation_class)
+
+    expect(parsed_hash).to eq(post_safe_hash)
+  end
+end