Fix FK CPK (#1396)

lib/shoulda/matchers/active_record/association_matcher.rb

@@ -1397,14 +1397,23 @@ def class_has_foreign_key?(klass)
           if options.key?(:foreign_key) && !foreign_key_correct?
             @missing = foreign_key_failure_message(klass, options[:foreign_key])
             false
-          elsif !column_names_for(klass).include?(foreign_key)
+          elsif !has_column?(klass, foreign_key)
             @missing = foreign_key_failure_message(klass, foreign_key)
             false
           else
             true
           end
         end
 
+        def has_column?(klass, column)
+          case column
+          when Array
+            column.all? { |c| has_column?(klass, c) }
+          else
+            column_names_for(klass).include?(column)
+          end
+        end
+
         def foreign_key_correct?
           option_verifier.correct_for_string?(
             :foreign_key,
@@ -1434,12 +1443,18 @@ def primary_key_correct?(klass)
         end
 
         def foreign_key
-          if foreign_key_reflection
-            if foreign_key_reflection.respond_to?(:foreign_key)
-              foreign_key_reflection.foreign_key.to_s
-            else
-              foreign_key_reflection.primary_key_name.to_s
-            end
+          key = if foreign_key_reflection
+                  if foreign_key_reflection.respond_to?(:foreign_key)
+                    foreign_key_reflection.foreign_key
+                  else
+                    foreign_key_reflection.primary_key_name
+                  end
+                end
+
+          if key.is_a?(Array)
+            key.map(&:to_s)
+          else
+            key.to_s
           end
         end
 

spec/unit/shoulda/matchers/active_record/association_matcher_spec.rb

@@ -1414,7 +1414,7 @@ def having_many_non_existent_class(model_name, assoc_name, options = {})
       expect(having_one_non_existent(:person, :detail, class_name: 'Detail')).not_to have_one(:detail)
     end
 
-    it 'rejects an association with a valid :class_name and a bad :primary_key option' do
+    it 'rejects an association with a valid :class_name and a bad :foreign_key option' do
       define_model :person_detail
       define_model :person do
         has_one :detail, class_name: 'PersonDetail', foreign_key: :person_detail_id
@@ -1428,6 +1428,48 @@ def having_many_non_existent_class(model_name, assoc_name, options = {})
         and_fail_with(expected_message)
     end
 
+    it 'rejects an association with a valid :class_name and a bad :foreign_key option (CPK)' do
+      define_model :person_detail
+      define_model :person do
+        has_one :detail, class_name: 'PersonDetail', foreign_key: %i[company_id person_detail_id]
+      end
+
+      expected_message = 'Expected Person to have a has_one association called detail ' \
+        '(PersonDetail does not have a [:foo_id, :bar_id] foreign key.)'
+
+      expect do
+        have_one(:detail).class_name('PersonDetail').
+          with_foreign_key(%i[foo_id bar_id])
+      end.not_to match_against(Person.new).and_fail_with(expected_message)
+    end
+
+    it 'rejects an association with a valid :class_name and :foreign_key option (CPK), but no columns' do
+      define_model :person_detail
+      define_model :person do
+        has_one :detail, class_name: 'PersonDetail', foreign_key: %i[company_id person_detail_id]
+      end
+
+      expected_message = 'Expected Person to have a has_one association called detail ' \
+        '(PersonDetail does not have a ["company_id", "person_detail_id"] foreign key.)'
+
+      expect do
+        have_one(:detail).class_name('PersonDetail').
+          with_foreign_key(%i[company_id person_detail_id])
+      end.not_to match_against(Person.new).and_fail_with(expected_message)
+    end
+
+    it 'accepts an association with a valid :class_name and :foreign_key option (CPK)' do
+      define_model :person_detail, company_id: :integer, person_detail_id: :integer
+      define_model :person do
+        has_one :detail, class_name: 'PersonDetail', foreign_key: %i[company_id person_detail_id]
+      end
+
+      expect(Person.new).
+        to have_one(:detail).
+        class_name('PersonDetail').
+        with_foreign_key(%i[company_id person_detail_id])
+    end
+
     it 'adds error message when rejecting an association with non-existent class' do
       message = 'Expected Person to have a has_one association called detail (Detail2 does not exist)'
       expect {