adjust implementation of can_resolve? and add tests

app/services/metadata_service.rb

@@ -12,14 +12,13 @@ def known_prefixes
     end
 
     def can_resolve?(identifier)
-      (prefix, _identifier) = identifier.split(/:/, 2)
-      handlers.key?(prefix.to_sym)
+      known_prefixes.any? { |prefix| identifier.start_with?(prefix.to_s) }
     end
 
     # return the identifiers found in the same order of the known prefixes we specified
     def resolvable(identifiers)
       res_ids = identifiers.select { |identifier| can_resolve?(identifier) }
-      MetadataService.known_prefixes.map { |prefix| res_ids.find { |res_id| res_id.start_with?(prefix.to_s) } }.compact
+      known_prefixes.map { |prefix| res_ids.find { |res_id| res_id.start_with?(prefix.to_s) } }.compact
     end
 
     def fetch(identifier)

spec/services/metadata_service_spec.rb

@@ -21,6 +21,20 @@
     end
   end
 
+  describe 'can_resolve?' do
+    it 'returns false for an unknown prefix' do
+      expect(described_class).not_to be_can_resolve('bogus:1234')
+    end
+
+    it 'returns true for barcodes' do
+      expect(described_class).to be_can_resolve('barcode:1234')
+    end
+
+    it 'returns true for catkeys' do
+      expect(described_class).to be_can_resolve('catkey:1234')
+    end
+  end
+
   describe 'Symphony handler' do
     let(:resource) { instance_double(MarcxmlResource, mods: mods) }
     let(:mods) { File.read(File.join(fixture_dir, 'mods_record.xml')) }