Kill mutations in Mutant::Result.included

spec/unit/mutant/result_spec.rb

@@ -0,0 +1,23 @@
+RSpec.describe Mutant::Result do
+  describe '.included' do
+    let(:object) do
+      Class.new do
+        include Mutant::Result
+
+        def collection
+          [[1]]
+        end
+
+        sum :length, :collection
+      end.new
+    end
+
+    it 'includes mixin to freeze instances' do
+      expect(object.frozen?).to be(true)
+    end
+
+    it 'it makes DSL methods from Mutant::Result available' do
+      expect(object.length).to be(1)
+    end
+  end
+end