Support qualifier(optional, required) of 'belongs_to'

lib/shoulda/matchers/active_record/association_matcher.rb

@@ -937,6 +937,17 @@ def with_primary_key(primary_key)
           self
         end
 
+        # TODO: Removed when Rails 4.2 support finished.
+        def required(required = true)
+          @options[:required] = required
+          self
+        end
+
+        def optional(optional = true)
+          @options[:optional] = optional
+          self
+        end
+
         def validate(validate = true)
           @options[:validate] = validate
           self
@@ -975,6 +986,8 @@ def matches?(subject)
             primary_key_exists? &&
             class_name_correct? &&
             join_table_correct? &&
+            required_correct? && # TODO: Removed when Rails 4.2 support finished.
+            optional_correct? &&
             autosave_correct? &&
             conditions_correct? &&
             validate_correct? &&
@@ -1130,6 +1143,33 @@ def autosave_correct?
           end
         end
 
+        # TODO: Removed when Rails 4.2 support finished.
+        def required_correct?
+          if options.key?(:required)
+            if option_verifier.correct_for_boolean?(:required, options[:required])
+              true
+            else
+              @missing = "#{name} should have required set to #{options[:required]}"
+              false
+            end
+          else
+            true
+          end
+        end
+
+        def optional_correct?
+          if options.key?(:optional)
+            if option_verifier.correct_for_boolean?(:optional, options[:optional])
+              true
+            else
+              @missing = "#{name} should have optional set to #{options[:optional]}"
+              false
+            end
+          else
+            true
+          end
+        end
+
         def conditions_correct?
           if options.key?(:conditions)
             if option_verifier.correct_for_relation_clause?(:conditions, options[:conditions])

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

@@ -53,6 +53,44 @@
       expect(Child.new).to belong_to(:parent)
     end
 
+    # TODO: Removed when Rails 4.2 support finished.
+    it 'accepts an association with a valid :required option' do
+      begin
+        expect(belonging_to_parent(required: true)).
+          to belong_to(:parent).required
+      rescue
+        skip 'This version does not support required qualifier'
+      end
+    end
+
+    # TODO: Removed when Rails 4.2 support finished.
+    it 'accepts an association with a valid :required option' do
+      begin
+        expect(belonging_to_parent(required: false)).
+          not_to belong_to(:parent).required
+      rescue
+        skip 'This version does not support required qualifier'
+      end
+    end
+
+    it 'accepts an association with a valid :optional option' do
+      begin
+        expect(belonging_to_parent(optional: true)).
+          to belong_to(:parent).optional
+      rescue
+        skip 'This version does not support optional qualifier'
+      end
+    end
+
+    it 'accepts an association with a valid :optional option' do
+      begin
+        expect(belonging_to_parent(optional: false)).
+          not_to belong_to(:parent).optional
+      rescue
+        skip 'This version does not support optional qualifier'
+      end
+    end
+
     it 'accepts an association with a valid :dependent option' do
       expect(belonging_to_parent(dependent: :destroy)).
         to belong_to(:parent).dependent(:destroy)