Updated: How to set up database_cleaner for Rails with Cucumber and RSpec
RSpec
# spec/support/database_cleaner.rb
RSpec.configure do |config|
config.before(:suite) do
DatabaseCleaner.strategy = :transaction
DatabaseCleaner.clean_with(:deletion)
end
config.around do |example|
DatabaseCleaner.start
example.run
DatabaseCleaner.clean
end
end
# spec/spec_helper.rb
RSpec.configure do |config|
config.use_transactional_fixtures = false
end
Don't use before hooks here otherwise around hooks are not within the transaction and your database is therefore not cleaned pro…
Helper methods - RSpec Core
You can define methods in any example group using Ruby's def keyword or define_method method. These helper methods are exposed to examples in the group in which they are defined and groups nested within that group, but not parent or sibling groups.
Migrating legacy data into new application
There are many approaches out there how you can import data from a legacy application to a new application. Here is an approach which opens two database connections and uses active record for the legacy system, too:
1. Add you database information to you config/database.yml.
data_migration:
database: your_application_data_migration
2. Create a separate application record for the data migration, e.g. in app/data_migration/migration_record.rb. You will need to create an app/data_migration.rb class first.
```
class DataMig…
An auto-mapper for ARIA labels and BEM classes in Cucumber selectors
Spreewald comes with a selector_for helper that matches an English term like the user's profile into a CSS selector. This is useful for steps that refer to a particular section of the page, like the following:
Then I should see "Bruce" within the user's profile
^^^^^^^^^^^^^^^^^^
If you're too lazy to manually translate English to a CSS selector by adding a line to features/env/selectors.rb, we already have an [auto-mapper to translate English into …
Git: Improve your commits by reviewing changes one-by-one
Git commits should be very deliberate, and only contain changes that you really want to be in there. In order to reduce the chance to accidentally commit something you didn't intend, review your changes before committing.
My preferred way of doing this is (only using git)
git add -N . # Add all paths, but not their contents
git add -p
Git will now show you all your changes in small chunks and ask you in an interactive mode whether you really want to add them.
The most helpful commands are
- y: yes (add the change)
- …
Async/Await Will Make Your Code Simpler
Sometimes modern Javascript projects get out of hand. A major culprit in this can be the messy handling of asynchronous tasks, leading to long, complex, and deeply nested blocks of code. Javascript now provides a new syntax for handling these operations, and it can turn even the most convoluted asynchronous operations into concise and highly readable code.
Rspec: around(:all) and around(:each) hook execution order
Summary
-
around(:suite)does not exist. -
around(:all)runs afterbefore(:all)and beforeafter(:all). -
around(:each)runs beforebefore(:each)and afterafter(:each).
As this is not 100% obvious (and not yet documented) it is written down in this card. In RSpec 3 :each has the alias :example and :all the alias :context.
Example
```
RSpec.configure do |config|
config.before(:suite) { puts 'BEFORE :suite' }
config.after(:suite) { puts 'AFTER :suite' }
end
describe 'order of hook execution' do
around(:a…
Using pure Sass functions to make reusable logic more useful - Advanced
Functions and mixins are very similar in nature. Because they can both accept variables, you might end up creating a mixin when what you really need is a function.
Why two Ruby Time objects are not equal, although they appear to be
So you are comparing two Time objects in an RSpec example, and they are not equal, although they look equal:
expected: Tue May 01 21:59:59 UTC 2007,
got: Tue May 01 21:59:59 UTC 2007 (using ==)
The reason for this is that Time actually tracks fractions of a second, although #to_s doesn't say so and even though you probably only care about seconds. This means that two consecutive calls of Time.now probably return two inequal values.
If you only care about second precision you can compare two Times by calling #to_i …
CSS Support Guide for Email Clients
CSS support in major e-mail clients is horrible.
This will give you an overview what you will not be able to use across all clients.
How to use a local gem in your Gemfile
You can use local copies of gems in your Gemfile like this:
gem 'spreewald', :path => '~/gems/spreewald'
As soon as you have bundled your project with the local copy of the gem, all code changes in the copy will be available on your project. So you can for example set a debugger (or add console output) in the gem and use it from your project.
If you checked out the gem using git (or any other versioning tool), you can easily reset your changes afterwards or make a pull request for the gem if you improved it.
Rails: When defining scopes with class methods, don't use `self`
Sometimes it is useful to define a named scope by implementing a static method with the scope's name on the scoped class. For instance, when a method should decide which existing scope should be the next link in the scope chain. Take this class for example:
class Meal < ActiveRecord::Base
named_scope :for_date, lambda { |date| :conditions => { :date => date }}
named_scope :with_meat, :conditions => { :meat => true }
named_scope :without_meat, :conditions => { :meat => false }
def self.suitable_for(user)
...