Add generator spec generator and specs (#2085)

Added generator spec generator

lib/generators/rspec/generators/generator_generator.rb

@@ -0,0 +1,24 @@
+require 'generators/rspec'
+
+module Rspec
+  module Generators
+    # @private
+    class GeneratorsGenerator < Base
+      class_option :generator_specs, :type => :boolean, :default => false,  :desc => "Generate generator specs"
+
+      def generate_generator_spec
+        return unless options[:generator_specs]
+
+        template template_name, File.join('spec/generator', class_path, filename)
+      end
+
+      def template_name
+        'generator_spec.rb'
+      end
+
+      def filename
+        "#{table_name}_generator_spec.rb"
+      end
+    end
+  end
+end

lib/generators/rspec/generators/templates/generator_spec.rb

@@ -0,0 +1,6 @@
+require 'rails_helper'
+
+RSpec.describe "<%= class_name.pluralize %>", <%= type_metatag(:generator) %> do
+
+  pending "add some scenarios (or delete) #{__FILE__}"
+end

spec/generators/rspec/generators/generator_generator_spec.rb

@@ -0,0 +1,35 @@
+require 'generators/rspec/generators/generator_generator'
+require 'support/generators'
+
+RSpec.describe Rspec::Generators::GeneratorsGenerator, :type => :generator do
+  setup_default_destination
+
+  describe "generator specs" do
+    subject(:generator_spec) { file("spec/generator/posts_generator_spec.rb") }
+    describe "are generated independently/can be generated" do
+      before do
+        run_generator %w(posts --generator-specs)
+      end
+      it "creates the spec file" do
+        expect(generator_spec).to exist
+      end
+      it "contains 'rails_helper in the spec file'" do
+        expect(generator_spec).to contain(/require 'rails_helper'/)
+      end
+      it "includes the generator type in the metadata" do
+        expect(generator_spec).to contain(/^RSpec.describe \"Posts\", #{type_metatag(:generator)}/)
+      end
+    end
+
+    describe "are not generated/are skipped by default" do
+      before do
+        run_generator %w(posts)
+      end
+      describe "the spec" do
+        it "does not exist" do
+          expect(generator_spec).to_not exist
+        end
+      end
+    end
+  end
+end