add option to use a custom template for generate extension

.gitignore

@@ -8,3 +8,4 @@ Gemfile.lock
 .ruby-version
 .bundle
 pkg
+tmp

lib/solidus_cmd/extension.rb

@@ -8,29 +8,22 @@ class Extension < Thor::Group
     desc "builds a solidus extension"
     argument :file_name, type: :string, desc: 'rails app_path', default: '.'
 
-    source_root File.expand_path('../templates/extension', __FILE__)
+    class_option :template
+
+    def self.source_root
+      File.expand_path('../', __FILE__)
+    end
 
     def generate
+      template = options[:template] ? options[:template] : 'template.rb'
+
+      find_in_source_paths(template)
+
       use_prefix 'solidus_'
 
       empty_directory file_name
 
-      directory 'app', "#{file_name}/app"
-      directory 'lib', "#{file_name}/lib"
-      directory 'bin', "#{file_name}/bin"
-
-      template 'extension.gemspec', "#{file_name}/#{file_name}.gemspec"
-      template 'Gemfile', "#{file_name}/Gemfile"
-      template 'gitignore', "#{file_name}/.gitignore"
-      template 'LICENSE', "#{file_name}/LICENSE"
-      template 'Rakefile', "#{file_name}/Rakefile"
-      template 'README.md', "#{file_name}/README.md"
-      template 'config/routes.rb', "#{file_name}/config/routes.rb"
-      template 'config/locales/en.yml', "#{file_name}/config/locales/en.yml"
-      template 'rspec', "#{file_name}/.rspec"
-      template 'spec/spec_helper.rb.tt', "#{file_name}/spec/spec_helper.rb"
-      template 'rubocop.yml', "#{file_name}/.rubocop.yml"
-      template 'travis.yml', "#{file_name}/.travis.yml"
+      apply template
     end
 
     no_tasks do

lib/solidus_cmd/template.rb

@@ -0,0 +1,18 @@
+source_paths.unshift(File.expand_path('../templates/extension', __FILE__))
+
+directory 'app', "#{file_name}/app"
+directory 'lib', "#{file_name}/lib"
+directory 'bin', "#{file_name}/bin"
+
+template 'extension.gemspec', "#{file_name}/#{file_name}.gemspec"
+template 'Gemfile', "#{file_name}/Gemfile"
+template 'gitignore', "#{file_name}/.gitignore"
+template 'LICENSE', "#{file_name}/LICENSE"
+template 'Rakefile', "#{file_name}/Rakefile"
+template 'README.md', "#{file_name}/README.md"
+template 'config/routes.rb', "#{file_name}/config/routes.rb"
+template 'config/locales/en.yml', "#{file_name}/config/locales/en.yml"
+template 'rspec', "#{file_name}/.rspec"
+template 'spec/spec_helper.rb.tt', "#{file_name}/spec/spec_helper.rb"
+template 'rubocop.yml', "#{file_name}/.rubocop.yml"
+template 'travis.yml', "#{file_name}/.travis.yml"

spec/extension_spec.rb

@@ -0,0 +1,26 @@
+require 'spec_helper'
+
+RSpec.describe SolidusCmd::Extension do
+  it 'generate skeleton' do
+    run_extension
+    dir = '../tmp/solidus_dummy_ext'
+    expect(Dir.exist?(dir)).to be(true)
+    expect(File.exist?("#{dir}/solidus_dummy_ext.gemspec")).to be(true)
+    expect(File.exist?("#{dir}/Gemfile")).to be(true)
+    expect(File.exist?("#{dir}/Rakefile")).to be(true)
+  end
+
+  it 'allow use custom template' do
+    template_path = '../../spec/fixtures/dummy_template.rb'
+    run_extension(['dummy', '--template', template_path])
+    dir = '../tmp/solidus_dummy'
+    expect(Dir.exist?(dir)).to be(true)
+    expect(File.exist?("#{dir}/solidus_dummy.gemspec")).to be(true)
+    expect(File.exist?("#{dir}/Gemfile")).to be(false)
+  end
+
+  it 'not create extension when template path is invalid' do
+    run_extension(['dummy', '--template', '/invalid/path'])
+    expect(Dir.exist?('../tmp/solidus_dummy')).to be(false)
+  end
+end

spec/fixtures/dummy_template.rb

@@ -0,0 +1,3 @@
+source_paths.unshift(File.expand_path('../../../lib/solidus_cmd/templates/extension', __FILE__))
+
+template 'extension.gemspec', "#{file_name}/#{file_name}.gemspec"

spec/spec_helper.rb

@@ -1,3 +1,5 @@
+require 'support/extension_helper'
+
 if ENV["COVERAGE"]
   # Run Coverage report
   require 'simplecov'
@@ -18,10 +20,7 @@
 RSpec.configure do |config|
   config.color = true
   config.mock_with :rspec
-
-  config.fixture_path = "#{::Rails.root}/spec/fixtures"
-
-  config.use_transactional_fixtures = false
+  config.include ExtensionHelper
 
   config.fail_fast = ENV['FAIL_FAST'] || false
 end

spec/support/extension_helper.rb

@@ -0,0 +1,15 @@
+require 'solidus_cmd/extension'
+
+module ExtensionHelper
+  include FileUtils
+
+  def run_extension(args = ['dummy_ext'], config = {})
+    clear_destination
+    config.merge!(destination_root: '../tmp')
+    SolidusCmd::Extension.start(args, config)
+  end
+
+  def clear_destination(dir = '../tmp')
+    Dir.exist?(dir) ? rm_rf(dir) : nil
+  end
+end