From 3833cdab2ab13164c79d63c158c77ed775925f05 Mon Sep 17 00:00:00 2001 From: Les Hill Date: Sun, 23 Oct 2011 15:50:11 -0700 Subject: [PATCH] Explain what this is all about then. --- README | 261 ------------------------------------------------------ README.md | 159 +++++++++++++++++++++++++++++++++ 2 files changed, 159 insertions(+), 261 deletions(-) delete mode 100644 README create mode 100644 README.md diff --git a/README b/README deleted file mode 100644 index 7c36f23..0000000 --- a/README +++ /dev/null @@ -1,261 +0,0 @@ -== Welcome to Rails - -Rails is a web-application framework that includes everything needed to create -database-backed web applications according to the Model-View-Control pattern. - -This pattern splits the view (also called the presentation) into "dumb" -templates that are primarily responsible for inserting pre-built data in between -HTML tags. The model contains the "smart" domain objects (such as Account, -Product, Person, Post) that holds all the business logic and knows how to -persist themselves to a database. The controller handles the incoming requests -(such as Save New Account, Update Product, Show Post) by manipulating the model -and directing data to the view. - -In Rails, the model is handled by what's called an object-relational mapping -layer entitled Active Record. This layer allows you to present the data from -database rows as objects and embellish these data objects with business logic -methods. You can read more about Active Record in -link:files/vendor/rails/activerecord/README.html. - -The controller and view are handled by the Action Pack, which handles both -layers by its two parts: Action View and Action Controller. These two layers -are bundled in a single package due to their heavy interdependence. This is -unlike the relationship between the Active Record and Action Pack that is much -more separate. Each of these packages can be used independently outside of -Rails. You can read more about Action Pack in -link:files/vendor/rails/actionpack/README.html. - - -== Getting Started - -1. At the command prompt, create a new Rails application: - rails new myapp (where myapp is the application name) - -2. Change directory to myapp and start the web server: - cd myapp; rails server (run with --help for options) - -3. Go to http://localhost:3000/ and you'll see: - "Welcome aboard: You're riding Ruby on Rails!" - -4. Follow the guidelines to start developing your application. You can find -the following resources handy: - -* The Getting Started Guide: http://guides.rubyonrails.org/getting_started.html -* Ruby on Rails Tutorial Book: http://www.railstutorial.org/ - - -== Debugging Rails - -Sometimes your application goes wrong. Fortunately there are a lot of tools that -will help you debug it and get it back on the rails. - -First area to check is the application log files. Have "tail -f" commands -running on the server.log and development.log. Rails will automatically display -debugging and runtime information to these files. Debugging info will also be -shown in the browser on requests from 127.0.0.1. - -You can also log your own messages directly into the log file from your code -using the Ruby logger class from inside your controllers. Example: - - class WeblogController < ActionController::Base - def destroy - @weblog = Weblog.find(params[:id]) - @weblog.destroy - logger.info("#{Time.now} Destroyed Weblog ID ##{@weblog.id}!") - end - end - -The result will be a message in your log file along the lines of: - - Mon Oct 08 14:22:29 +1000 2007 Destroyed Weblog ID #1! - -More information on how to use the logger is at http://www.ruby-doc.org/core/ - -Also, Ruby documentation can be found at http://www.ruby-lang.org/. There are -several books available online as well: - -* Programming Ruby: http://www.ruby-doc.org/docs/ProgrammingRuby/ (Pickaxe) -* Learn to Program: http://pine.fm/LearnToProgram/ (a beginners guide) - -These two books will bring you up to speed on the Ruby language and also on -programming in general. - - -== Debugger - -Debugger support is available through the debugger command when you start your -Mongrel or WEBrick server with --debugger. This means that you can break out of -execution at any point in the code, investigate and change the model, and then, -resume execution! You need to install ruby-debug to run the server in debugging -mode. With gems, use sudo gem install ruby-debug. Example: - - class WeblogController < ActionController::Base - def index - @posts = Post.all - debugger - end - end - -So the controller will accept the action, run the first line, then present you -with a IRB prompt in the server window. Here you can do things like: - - >> @posts.inspect - => "[#nil, "body"=>nil, "id"=>"1"}>, - #"Rails", "body"=>"Only ten..", "id"=>"2"}>]" - >> @posts.first.title = "hello from a debugger" - => "hello from a debugger" - -...and even better, you can examine how your runtime objects actually work: - - >> f = @posts.first - => #nil, "body"=>nil, "id"=>"1"}> - >> f. - Display all 152 possibilities? (y or n) - -Finally, when you're ready to resume execution, you can enter "cont". - - -== Console - -The console is a Ruby shell, which allows you to interact with your -application's domain model. Here you'll have all parts of the application -configured, just like it is when the application is running. You can inspect -domain models, change values, and save to the database. Starting the script -without arguments will launch it in the development environment. - -To start the console, run rails console from the application -directory. - -Options: - -* Passing the -s, --sandbox argument will rollback any modifications - made to the database. -* Passing an environment name as an argument will load the corresponding - environment. Example: rails console production. - -To reload your controllers and models after launching the console run -reload! - -More information about irb can be found at: -link:http://www.rubycentral.org/pickaxe/irb.html - - -== dbconsole - -You can go to the command line of your database directly through rails -dbconsole. You would be connected to the database with the credentials -defined in database.yml. Starting the script without arguments will connect you -to the development database. Passing an argument will connect you to a different -database, like rails dbconsole production. Currently works for MySQL, -PostgreSQL and SQLite 3. - -== Description of Contents - -The default directory structure of a generated Ruby on Rails application: - - |-- app - | |-- assets - | |-- images - | |-- javascripts - | `-- stylesheets - | |-- controllers - | |-- helpers - | |-- mailers - | |-- models - | `-- views - | `-- layouts - |-- config - | |-- environments - | |-- initializers - | `-- locales - |-- db - |-- doc - |-- lib - | `-- tasks - |-- log - |-- public - |-- script - |-- test - | |-- fixtures - | |-- functional - | |-- integration - | |-- performance - | `-- unit - |-- tmp - | |-- cache - | |-- pids - | |-- sessions - | `-- sockets - `-- vendor - |-- assets - `-- stylesheets - `-- plugins - -app - Holds all the code that's specific to this particular application. - -app/assets - Contains subdirectories for images, stylesheets, and JavaScript files. - -app/controllers - Holds controllers that should be named like weblogs_controller.rb for - automated URL mapping. All controllers should descend from - ApplicationController which itself descends from ActionController::Base. - -app/models - Holds models that should be named like post.rb. Models descend from - ActiveRecord::Base by default. - -app/views - Holds the template files for the view that should be named like - weblogs/index.html.erb for the WeblogsController#index action. All views use - eRuby syntax by default. - -app/views/layouts - Holds the template files for layouts to be used with views. This models the - common header/footer method of wrapping views. In your views, define a layout - using the layout :default and create a file named default.html.erb. - Inside default.html.erb, call <% yield %> to render the view using this - layout. - -app/helpers - Holds view helpers that should be named like weblogs_helper.rb. These are - generated for you automatically when using generators for controllers. - Helpers can be used to wrap functionality for your views into methods. - -config - Configuration files for the Rails environment, the routing map, the database, - and other dependencies. - -db - Contains the database schema in schema.rb. db/migrate contains all the - sequence of Migrations for your schema. - -doc - This directory is where your application documentation will be stored when - generated using rake doc:app - -lib - Application specific libraries. Basically, any kind of custom code that - doesn't belong under controllers, models, or helpers. This directory is in - the load path. - -public - The directory available for the web server. Also contains the dispatchers and the - default HTML files. This should be set as the DOCUMENT_ROOT of your web - server. - -script - Helper scripts for automation and generation. - -test - Unit and functional tests along with fixtures. When using the rails generate - command, template test files will be generated for you and placed in this - directory. - -vendor - External libraries that the application depends on. Also includes the plugins - subdirectory. If the app has frozen rails, those gems also go here, under - vendor/rails/. This directory is in the load path. diff --git a/README.md b/README.md new file mode 100644 index 0000000..029ff7f --- /dev/null +++ b/README.md @@ -0,0 +1,159 @@ +# Fast Specs! + +Nothing sucks the joy out of writing your Rails app like having an incredibly slow test suite. Even running one file with a single spec on my *new* MacBookPro takes almost five seconds! + + % time rspec spec/models/publish_spec.rb + . + + Finished in 4.48 seconds + 1 example, 0 failures + + real 0m4.592s + user 0m3.990s + sys 0m0.536s + +Wait, maybe we can just run `ruby`? + + % time ruby -Ispec spec/models/publish_spec.rb + . + + Finished in 0.71331 seconds + 1 example, 0 failures + + real 0m4.468s + user 0m3.953s + sys 0m0.512s + +Five. + +Seconds. + +**F I V E SECONDS**. + +*One Mississippi*, *Two Mississippi*, *Three Mississippi*, *Four Mississippi*, *Five Mississippi*. + +An eternity. + +Let's take a look at the admittedly ridiculous and contrived spec: + + it "publishes the item to the syndicate" do + syndicate = double() + syndicate.should_receive(:publish).with(item) + item.publish_to(syndicate) + end + +Maybe there is a `sleep` hiding inside `#publish_to`? + + def publish_to(syndicate) + syndicate.publish(self) + end + +Nope. + +Very little of the time spent has to do with either the code under test, or the testing code. The majority of the time is just getting the test to run. + +The source of most of this is the default `spec_helper.rb` that `RSpec` generates to load up our test environment. + +Asking around about this on Twitter (you should follow me [@leshill](http://twitter.com/leshill) :) yielded no examples on how you might write your specs to get some of that time back. So I wrote fast\_specs to demonstrate how to make your own specs faster. + +## Writing Fast Specs + +This app has two spec suites, one a normal `RSpec` suite that can be invoked as a whole with: + + % rake spec + +Or invoked with individual specs with: + + % rspec spec/models/publish_spec.rb + % ruby -Ispec spec/models/publish_spec.rb + +And a **Fast Spec** suite that can be invoked as a while with: + + % rake fast + +Or invoked with individual specs with: + + % rspec -Ifast_specs fast_specs/models/publish_spec.rb + +In order to use the **Fast Spec** suite, we put our *fast* specs under `fast_specs` much like we do with normal `RSpec` specs. For example, the spec for the `Publish` model would be located at `fast_specs/modesl/publish_spec.rb`. + +At the top of our simple spec, with no changes to the implementation or the contents of the `describe` block, we require the `fast_spec_helper`, and the `Publish` model: + + require 'fast_spec_helper' + + app_require 'app/models/publish' + +`fast_spec_helper` adds a tiny bit of sugar by providing `app_require` which just wraps loading files from your app. + +Now when we run it: + + % time rspec -Ifast_specs fast_specs/models/publish_spec.rb + . + + real 0m0.249s + user 0m0.183s + sys 0m0.064s + + Finished in 0.17153 seconds + 1 example, 0 failures + +**One quarter of a second.** + +*Oh point two five* seconds. + +Much faster. + +**GO!** **FAST** **FASTER** **FASTEST** **GO!** + +## Give me some support + +Sometimes our code has some coupling to other parts of the system, and in those cases, we can just require the parts that we need during our spec. For example, if our `Post` depends on `Publish` our requires would look like: + + require 'fast_spec_helper' + + app_require 'app/models/publish' + app_require 'app/models/post' + +Not all specs are written completely with mocks (although more should be), and sometimes we need additional setup. For example, lets say that we are moving an existing *classic* TDD model spec for our `Post` that looks like this: + + it "creates a post" do + expect do + Post.create(title: 'a title', body: 'some body text') + end.to change(Post, :count).from(0).to(1) + end + +This spec requires accessing the database and ensuring some sort of *transactional fixture* support. We can write these support files, place them in them in `fast_specs/support` and then require them using another tiny bit of sugar with `support_require` to load our support files: + + require 'fast_spec_helper' + + support_require 'database' + support_require 'database_cleaner' + + app_require 'app/models/publish' + app_require 'app/models/post' + +Timing this spec (which is using a transaction on the database) yields: + + % time rspec -Ifast_specs fast_specs/models/post_spec.rb + . + + Finished in 0.80608 seconds + 1 example, 0 failures + + real 0m0.890s + user 0m0.701s + sys 0m0.170s + +Not bad. And most definitely faster than our previous isolated spec was :) + +### Make this better! + +This is only the beginning of making your specs faster. Yes, shaving 4 seconds off when running an individual spec is fantastic. If you have suggestions for more techniques or code that helps even further, make a pull request! + +## Thanks + +The approach outlined here is something that I just made up out of sheer frustration with the ridiculousness of waiting **5 seconds** for a simple spec. + +The idea of replacing the `spec_helper.rb` was first mentioned to me by Gary Bernhardt over dinner a while back. Corey Haines has also been advocating this approach in some of his talks (and which I would love to see one of these days :) + +And I know there was a blog post that suggested some serious stubbing for ActionController a while back (I cannot find it now, if you know it, please ping me.)