sandbox testing environments exist for TDD'ing command line application - ruby-on-rails

I'm writing a command line command but want to TDD it. I'll be creating and deleting files and was wondering if there's a sandbox testing gem or something like that. I'm using ruby and rspec.

Depends on what you're trying to do, but I test most of my command line Ruby by mocking out the file system and STDIN/STDOUT. Using dependency injection I often end up with something along these lines:
describe Add do
it 'writes the result to standard out' do
console = mock('STDOUT')
console.should_receive(:puts).with('5')
Add.new(console).execute(3,2)
end
end
class Add
def initialize(out = STDOUT)
#out = out
end
def execute(command_line_args)
#out.puts(command_line_args.inject(:+))
end
end
Add.new.execute(ARGS)
By using default values I can inject in the test, but leave it out of the production code.
Hope that helps!
Brandon

The template generated by the newgem install_cucumber generator uses a pattern that I like quite a bit. Have a look at the support/env.rb and support/common.rb files it creates:
https://github.com/drnic/newgem/blob/master/rubygems_generators/install_cucumber/templates/features/support/env.rb.erb
https://github.com/drnic/newgem/blob/master/rubygems_generators/install_cucumber/templates/features/support/common.rb
Use of it in test looks like this:
in_tmp_folder do
# The current directory is now a generated tmp folder.
# If you stick to relative paths, everything you do in here should be safe
end
The files linked to above are for using this in cucumber tests, but it could easily be adapter to whatever framework you're using. The env.rb above deletes the tmp folder before each test starts.

You might also want to take a look at the sandbox gem.
gem install sandbox
Example usage is here: https://github.com/bdimcheff/sandbox

Related

Rspec: Capybara server map a directory

I have a set of files in a folder under spec/support/fixtures directory. I need those files to be accessible through an uri such as "http://127.0.0.0:#{Capybara.current_session.server.port}/test_fixtures"
After many trail and errors I ended up the following solution: In rails_helper.rb I added the following code:
Capybara.app = Rack::Builder.new do
map '/' do
run Rails.application
end
map '/test_fixtures' do
run Rack::File.new('spec/support/fixtures')
end
end.to_app
It works well, but the solution to re-create Capybara app does not seem elegant to me. I'm looking for a better solution... or is it ok like this ?
Thanks
For your stated goal you have implemented things correctly and that is exactly what the Capybara.app setting is meant for. The only thing I would recommend doing is moving it into a separate file and requiring that file in your rails_helper.

Can I run a Rails engine's specs from a real app which mounts it?

I have a Rails Engine meant to provide some models and controllers to a larger project of ours. There's a pretty decent set of specs for the Engine, using a bunch of mocks and some full-scale models and controllers within the engine's dummy app to make sure the Engine is doing what it's supposed to and working with the larger application.
However, even with all tests passing, I frequently find broken behavior when I update the engine in the larger application. If my tests are passing but the behavior is broken, clearly something's wrong with the tests, but what? Am I mocking too much, or not enough?
To get me closer to figuring this out, I'd like to be able to run the engine's tests from inside the full application. This seems like it should be possible, but I don't understand rspec thoroughly enough to get a handle on how.
(This is related to this question but not quite the same; I'm not trying to run all the specs from one command, just to run the engine's specs within the full app environment. This also seems to be related. Actually, I've read every question tagged with both rspec and rails-engines--there aren't many--and they're all either not what I need, or unanswered.)
The simplest solution would be to specify the paths in rspec command. If you have directory structure
/project
/engine
/engine_2
Then you do and should run all the specs
cd project
rspec spec/ ../engine/spec ../engine_2/spec
But if you want to run specs on Continous Integration or just this doesn't seem to be comfortable I solved this problem with a customized rake spec task, changing the pattern method.
lib/task/rspec.rake should look like this
require "rspec/core/rake_task"
RSpec::Core::RakeTask.new(:spec)
task :default => :spec
RSpec::Core::RakeTask.module_eval do
def pattern
extras = []
Rails.application.config.rspec_paths.each do |dir|
if File.directory?( dir )
extras << File.join( dir, 'spec', '**', '*_spec.rb' ).to_s
end
end
[#pattern] | extras
end
end
In engine class you add a path to config.rspec_paths
class Engine < ::Rails::Engine
# Register path to rspec
config.rspec_paths << self.root
end
And don't forget to initialize config.rspec_paths somewhere in a base project.
If you want to add factories then you can create initializer, you can find solution somewhere here on stackoverflow.
Not sure if this solution is the best but works for me and I am happy with that. Good luck!

How to implement generators for a plugin located at the `lib/<plugin_name>` directory?

I am using Ruby on Rails 3.2.2. I have implemented a Something plugin (it is almost a gem, but is not a gem) and all related files are in the lib/something directory. Since I would like to automate code generation related to that plugin, I came up with Ruby on Rails Generators. So, for the Something plugin, I am looking for implementing my own generators in the lib/something directory.
How should I make that and what are prescriptions? That is, for example, what rails generate command line should be invoked to properly generate all needed files in the lib/something directory? generators would still work with plugins (not gem)? what are advices about this matter?
I would make it a gem. I've made generators using gems, but I don't know if the generators would still work with plugins.
If you are having difficulty with the command line, I am guessing that you don't need any argument. (If you need an argument, I could copy the provided templates, and if I needed some other argument I'd be lost, so my advise is limited to non-argument.)
I have a generator gem which generates migration files needed for another gem. It checks if the migration with a given root name (w/o the timestamp prefix) is in db/migrate, and otherwise creates it.
Here is my code. I think this example is the help you need.
class ItrcClientFilesGenerator < Rails::Generators::Base
source_root(File.dirname(__FILE__) + "/../src")
desc "Generator to create migrations for needed db tables"
def create_itrc_client_files
prefix = DateTime.now.strftime("%Y%m%d%H%M")
existing_migrations =
Dir.glob("db/migrate/*itrc*").map do |path|
File.basename(path).gsub(/^\d*_/, '')
end
Dir.glob(File.dirname(__FILE__) + "/../src/*").sort.each_with_index do |src_filepath, index|
src_filename = File.basename(src_filepath)
unless existing_migrations.include?(src_filename.gsub(/^\d*_/, '')) then
this_prefix = "#{prefix}#{'%02i' % index}_"
dst_filename = src_filename.gsub(/^\d*_/, this_prefix)
copy_file(src_filename, "db/migrate/" + dst_filename)
end
end
end
end

How to gemify a Rails (engine) plugin?

I have a engine style Rails plugin from which I can create a gem using Jeweler. But when I require it in my Rails environment (or erb) the models within the plugin are not loaded. I have followed a number of tutorials and read just about everything on the subject.
# environment.rb
config.gem 'myengine'
# in irb
require 'myengine'
I have unpacked the gem and verified that all files are present. My init.rb has been moved to a new folder called 'rails' as per. All files in 'lib' are automatically added to the $LOAD_PATH, so require 'myengine' runs lib/myengine.rb. I verified this by putting a puts 'hello' within.
Is it because of the physical presence of plugins in a known place that Rails can add all the models, controller etc. to the relevant load_paths? Do I need to replicate this manually when using a gem?
Would gemspec require_paths be a way of adding additional paths other than lib? I assume however that Rails does not just require every single file, but loads them on demand hence the need for the filename and class name to match?
%w{ models controllers helpers }.each do |dir|
path = File.join(File.dirname(__FILE__), 'app', dir) + '/'
$LOAD_PATH << path
puts 'requiring'
Dir.new(path).entries.each do |file|
if file =~ /\.rb/
puts file
require file
end
end
end
By adding the above to lib/myengine.rb all the models/controllers are required. But like I said in my question this is unlikely to be a good way forward.
Offhand I'd say the part about adding those directories to the search path is right on. What you shouldn't need to do is require each file manually (as you allude to in your last sentence). What Rails does when you reference a non-existent constant is to search for a file with the same name (underscored of course) in the load path.
If for some reason you can not abide by the constraint (think about it long and hard) then you are going to need to dig deeper into Rails and see how the reloading mechanism works so you can tie into it properly in development mode.
The problem was the files (in app) where not being added to the gem because when using Jeweler it only automatically adds files to required_paths which are committed to git.

Finding unused views/partials in Ruby on Rails

I'm currently working on a largish Ruby on Rails project. It's old enough and big enough that it's not clear if all views are actually in use.
Is there any script/plugin out there that can generate a list of unused view files?
Take a look at the following script on GitHub http://github.com/vinibaggio/discover-unused-partials
I wrote a script to find unused partials/views. I assumed, though, that "unused" means that a view-file is present for which no controller-method is defined (any more). The script does not check whether the view is called because there is no link from the default-route to it. This would have been far more complex.
Place the following script in the application's script folder:
#!/usr/bin/env ruby
require 'config/environment'
(Dir['app/controllers/*.rb'] - ['app/controllers/application.rb']).each do |c|
require c
base = File.basename(c, '.rb')
views = Hash.new
Dir["app/views/#{base.split('_')[0]}/*"].each do |v|
views.store(File.basename(v).split('.')[0], v)
end
unused_views = views.keys - Object.const_get(base.camelcase).public_instance_methods - ApplicationController.public_instance_methods
puts "Unused views for #{base.camelcase}:" if unused_views.size > 0
unused_views.each { |v| puts views[v] }
end
It is kinda hackish and unfinished, but it does the job - at least for me.
Execute it like this (you only need to change the execute-bit the first time with chmod):
chmod +x script/script_name
./script/script_name
Enjoy!
Just install and run the discover-unused-partials gem:
gem install discover-unused-partials
discover-unused-partials rails_root_directory
Iterate through your partials, grep (or awk) the project for the name of the file. Adjust your search regex to look for "render :partial" at beginning of line for generic partials (eg, "_form").

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