test for ontology_based? and refactor to use delegation #1632

app/models/sample_attribute.rb

@@ -22,6 +22,9 @@ class SampleAttribute < ApplicationRecord
   # sample type exists
   attr_reader :deferred_link_to_self
 
+  # whether this attribute is tied to a controlled vocab which has a source ontology
+  delegate :ontology_based?, to: :sample_controlled_vocab, allow_nil: true
+
   def title=(title)
     super
     store_accessor_name
@@ -59,11 +62,6 @@ def linked_custom_metadata_type
     nil
   end
 
-  # whether this attribute is tied to a controlled vocab which has a source ontology
-  def ontology_based?
-    controlled_vocab? && sample_controlled_vocab&.source_ontology.present?
-  end
-
   private
 
   def store_accessor_name

test/unit/sample_attribute_test.rb

@@ -330,6 +330,22 @@ class SampleAttributeTest < ActiveSupport::TestCase
     assert_equal '', attribute.short_pid
   end
 
+  test 'ontology_based?' do
+    attribute = FactoryBot.create(:sample_sample_attribute, sample_type: FactoryBot.create(:simple_sample_type))
+    refute attribute.ontology_based?
+
+    attribute = FactoryBot.create(:simple_string_sample_attribute, sample_type: FactoryBot.create(:simple_sample_type))
+    refute attribute.ontology_based?
+
+    attribute = FactoryBot.create(:apples_controlled_vocab_attribute, sample_type: FactoryBot.create(:simple_sample_type))
+    refute attribute.sample_controlled_vocab.ontology_based?
+    refute attribute.ontology_based?
+
+    attribute.sample_controlled_vocab = FactoryBot.create(:topics_controlled_vocab)
+    assert attribute.sample_controlled_vocab.ontology_based?
+    assert attribute.ontology_based?
+  end
+
   private
 
   def valid_value?(attribute, value)