Correctly recurse over nested field associations

app/models/dialog_field_association_validator.rb

@@ -14,15 +14,19 @@ def circular_references(associations)
   private
 
   def initial_paths(associations)
-    associations.flat_map { |key, values| values.map { |value| [key, value] } }
+    associations.flat_map { |key, values| values.map { |value| [key, value] if associations.key?(value) } }.compact
   end
 
   def walk_value_path(fieldname_being_triggered, associations, path)
-    while associations[fieldname_being_triggered].present?
-      return [fieldname_being_triggered, associations[fieldname_being_triggered].first] if path.include?(associations[fieldname_being_triggered].first)
-      path << associations[fieldname_being_triggered]
-      path.flatten!
-      fieldname_being_triggered = path.last
+    while associations[fieldname_being_triggered]
+      return [fieldname_being_triggered, (path & associations[fieldname_being_triggered]).first] if (path & associations[fieldname_being_triggered]).present?
+
+      associations[fieldname_being_triggered].map do |new_element|
+        path_copy = path.dup
+        path_copy << new_element
+        fieldname_being_triggered = new_element
+        walk_value_path(fieldname_being_triggered, associations, path_copy)
+      end
     end
   end
 end

spec/models/dialog_field_association_validator_spec.rb

@@ -12,9 +12,12 @@
 
     context "when the associations are not blank" do
       context "when there are no circular references" do
-        it "returns false" do
+        it "returns false on the trivial case" do
           expect(dialog_field_association_validator.circular_references("foo" => ["baz"])).to eq(false)
-          expect(dialog_field_association_validator.circular_references("foo" => %w(foo2 foo4), "foo2" => ["foo3"], "foo3" => ["foo4"])).to eq(false)
+        end
+
+        it "returns false on the non-trivial case" do
+          expect(dialog_field_association_validator.circular_references("e" => ["c"], "c" => ["a", "d"], "d" => ["a"])).to eq(false)
         end
       end