Add a WorkRelation to query against all works

app/search_builders/curation_concerns/work_relation.rb

@@ -0,0 +1,40 @@
+module CurationConcerns
+  class WorkRelation < ActiveFedora::Relation
+    def initialize(opts = {})
+      super(DummyModel, opts)
+    end
+
+    def equivalent_class?(klass)
+      CurationConcerns.config.curation_concerns.include?(klass)
+    end
+
+    def search_model_clause
+      clauses = CurationConcerns.config.curation_concerns.map do |k|
+        ActiveFedora::SolrQueryBuilder.construct_query_for_rel(has_model: k.to_s)
+      end
+      clauses.size == 1 ? clauses.first : "(#{clauses.join(' OR ')})"
+    end
+
+    class DummyModel
+      def self.primary_concern
+        CurationConcerns.config.curation_concerns.first
+      end
+
+      def self.delegated_attributes
+        primary_concern.delegated_attributes
+      end
+
+      def self.solr_query_handler
+        primary_concern.solr_query_handler
+      end
+
+      def self.default_sort_params
+        primary_concern.default_sort_params
+      end
+
+      def self.id_to_uri(*args)
+        primary_concern.id_to_uri(*args)
+      end
+    end
+  end
+end

spec/search_builders/curation_concerns/work_relation_spec.rb

@@ -0,0 +1,10 @@
+require 'spec_helper'
+
+RSpec.describe CurationConcerns::WorkRelation do
+  let!(:work) { create(:generic_work) }
+  let!(:file_set) { create(:file_set) }
+  let!(:collection) { create(:collection) }
+  it 'has works and not collections or file sets' do
+    expect(subject).to eq [work]
+  end
+end