add annotate_models config test

spec/lib/tasks/annotate_models_spec.rb

@@ -0,0 +1,30 @@
+require_relative '../../spec_helper'
+
+describe 'annotate_models rake task and Annotate.set_defaults' do
+  before do
+    Rake.application = Rake::Application.new
+    Rake::Task.define_task('environment')
+    Rake.load_rakefile('tasks/annotate_models.rake')
+  end
+
+  let(:annotate_models_argument) do
+    argument = nil
+    expect(AnnotateModels).to receive(:do_annotations) { |arg| argument = arg }
+    Rake::Task['annotate_models'].invoke
+    argument
+  end
+
+  describe 'with_comment_column' do
+    after { ENV.delete('with_comment_column') }
+    subject { annotate_models_argument[:with_comment_column] }
+
+    context 'when Annotate.set_defaults is not called (defaults)' do
+      it { is_expected.to be_falsey }
+    end
+
+    context 'when Annotate.set_defaults sets it to "true"' do
+      before { Annotate.set_defaults('with_comment_column' => 'true') }
+      it { is_expected.to be_truthy }
+    end
+  end
+end