When building a web application, one is tempted to claim it "done" too early. Make sure you check this list.

Different screen sizes and browsers

Desktops, tablets and mobile devices have all different screen resolutions. Does your design work on each of them?

• Choose which browsers to support. Make sure the page looks OK, is usable and working in these browsers.
• Use @media queries to build a responsive design
  • If you do not suppo...

By default, Rails views escape HTML in any strings you insert. If you want to insert HTML verbatim, you need to call #html_safe. However, #html_safe does not "unescape" a string. It merely marks a string as safe for unescaped insertion.

How html_safe works

Calling html_safe on a String returns a new object that looks and acts like a String, but actually is a ActiveSupport::SafeBuffer:

"foo".length
# => 3
"foo".class
# => String

"foo".html_safe.length
# => 3
"foo".html_safe.class
# => ActiveSupport::S...

In Selenium features the server and client are running in separate processes. Therefore, when mocking time with a tool like Timecop, the browser controlled by Selenium will still see the unmocked system time.

timemachine.js allows you to mock the client's time by monkey-patching into Javascript core classes. We use timemachine.js in combination with the Timecop gem to synchronize the local browser time to the ...

Add gem 'database_cleaner' to your Gemfile. Then:

Cucumber & Rails 3+

# features/support/database_cleaner.rb

DatabaseCleaner.clean_with(:deletion) # clean once, now
DatabaseCleaner.strategy = :transaction
Cucumber::Rails::Database.javascript_strategy = :deletion

Cucumber & Rails 2

The latest available cucumber-rails for Rails 2 automatically uses database_cleaner when cucumber/rails/active_record is required -- but only if transactional fixtures are off. To have database_cleaner work correctly:

1. Add the ...

Navigation

CTRL + SHIFT + ALT + N

Search for any symbol in your application, like CSS classes, Ruby classes, methods, helpers etc.

CTRL + SHIFT + N

Search for filename in your application (also dependencies)

CTRL + E

Open a list of recently opened files

ALT + POS1

Open a the navigation bar as a context menu. Allows you to quickly navigate between files.

CTRL + G

Go to line

Actions

CTRL + SHIFT + A

:...

You can hook into Slack when using Capistrano for deployment. The slackistrano gem does most of the heavy lifting for you. Its default messages are unobtrusive and can be adjusted easily.

When deploying, it posts to a Slack channel like this:

How to integrate

Integrating Slackistrano with Capistrano 3 is fairly simple.

[NOTE "If you are not a Slack...

There are three ways to define your own RSpec matchers, with increasing complexibility and options:

1) Use RSpec::Matchers.define

RSpec::Matchers.define :be_a_multiple_of do |expected|
  match do |actual|
    actual % expected == 0
  end
  
  # optional
  failure_message do |actual|
    "expected that #{actual} would be a multiple of #{expected}"
  end
  
  # optional
  failure_message_when_negated do |actual|
    "expected that #{actual} would not be a multiple of #{expected}"
  end
end

• This is automatically available i...

Middleman is a static page generator that brings many of the goodies that Rails developers are used to.

Out of the box, Middleman brings Haml, Sass, helpers etc. However, it can be configured to do even better. This card is a list of improvement hints for a Rails developer.

Gemfile

Remove tzinfo-data and wdm unless you're on Windows. Add these gems:

gem 'middleman-livereload'
gem 'middleman-sprockets' # Asset pipeline!

gem 'bootstrap-sass' # If you want to use Bootstrap

gem 'byebug'

gem 'capistrano'
gem 'capistrano-mid...

Recently I made an upgrade from Bootstrap 3 to Bootstrap 4 in a bigger project. Here are some tips how to plan and perform such an upgrade. The effort will scale with the size of the project and its structure. If your stylesheets already follow strict rules, it may take less time to adapt them to the new version.

Preparation

There are several gems and libraries that works well with bootstrap or provide at least stylesheets/plugins to easily integrate the bootstrap theme. But very often they only work with specific version or are no long...

While verifying doubles in RSpec is a good default, it is limited in the amount of methods it actually is able to verify.

The background is that RSpec can't verify dynamically defined methods, which is a known issue for the usage of helper_method and also the reason why [RSpec >= 3.6](http://rspec.info/blog/2017/05/rspec-3-6-has-been-rel...

Basic configuration

Please keep this config simple. It should be a starting point for new developers learning Git.

[user]
  name = Your Name
  email = your.name@domain.com

[branch]
  sort = -committerdate
[color]
   ui = auto
[color "branch"]
  current = yellow reverse
  local = yellow
  remote = green
[color "diff"]
  whitespace = white reverse
  meta = blue reverse
  frag = blue reverse
  old = red
  new = green
[color "status"]
  added = green
  changed = yellow
  untracked = cyan
[interactive]
  singlekey = true # Do not requir...

When an Rspec example fails, I usually investigate by running that example again using rspec <file:line>. However, this does not work with shared examples, since Rspec doesn't know in which context the shared example should be run.

But there is a different way: You can run the shared example using the -e, --example option. It takes a string value and runs all scenarios containing that substring in their full description.

This allows you to run a single uniquely named example, all examples with
similar names, all the examples in a u...

tl;dr

To adjust code templates in RubyMine, navigate to Settings -> Editor -> File and Code Templates.

Example

You can navigate to the test file of the currently open file with the shortcut Ctrl + T. If no test file exists, you can generate a new test file. If you are not pleased with the output, you can adjust the related code template. To do this, open the project settings and navigate to Editor -> File and Code Templates -> Files. Now, choose your relevant file type and adjust the code template according ...

Redis.current will be removed without replacement in redis-rb 5.0.
Version 4.6.0 adds deprecation warnings for Redis.current and Redis.current=:

`Redis.current=` is deprecated and will be removed in 5.0.

If your application still uses Redis.current, you can only fix it by no longer using it. Here is how.

Redis.new when you need it

You can easily instantiate a Redis client when you need it.

There is probably already a constant like REDIS_URL that you use to configure Sidekiq or similar. So just use that one.

``...

Static error pages

To add a few basic styles to the default error pages in Rails, just edit the default templates in public, e.g. public/404.html.

A limitation to these default templates is that they're just static files. You cannot use Haml, Rails helpers or your application layout here. If you need Rails to render your error pages, you need the approach below.

Dynamic error pages

1. Register your own app as the applicatio...

TL;DR Most web applications do not require action on this. SameSite=None (old browser default) will continue to work, and SameSite=Lax (new Chrome default, gradually rolled out) is an even better default for cookies. Set SameSite=Strict only for extra security in special cases (see below). If your application is rendered in an iframe (e.g. a video player or some news stream), you need to configure its relevant cookies as SameSite=None.

The SameSite cookie attribute targets **c...

Ruby's standard library includes a class for creating temporary directories. Similar to Tempfile it creates a unique directory name.

Note:

• You need to use a block or take care of the cleanup manually
• You can create a prefix and suffix e.g. Dir.mktmpdir(['foo', 'bar']) => /tmp/foo20220912-14561-3g93n1bar
• You can choose a different base directory than Dir.tmpdir e.g. `Dir.mktmpdir('foo', Rails.root.join('tmp')) => /home/user/rails_example/tmp/foo20220912-14...

View specs are a powerful tool to test several rendering paths by their cases instead of using a more costing feature spec. This is especially useful because they become quite convenient when used with Capybara::Node::Finders and Capybara::RSpecMatchers. This allows to wirte view unit specs as you can isolate specific part...

When you find similar groups of expect calls in your tests, you can improve readability by extracting the group into its own matcher. RSpec makes this easy by allowing matchers to call other matchers.

Example

The following test checks that two variables foo and bar (1) have no lowercase characters and (2) end with an exclamation mark:

expect(foo).to_not match(/[a-z]/)
expect(foo).to end_with('!')

expect(bar).to_not match(/[a-z]/)
expect(bar).to end_with('!')

We can extract the repeated matcher chains into a custom m...

While debugging a SPF record I found spf-record.de to be very helpful.

• it lists all IPs that are covered by the SPF record
• shows syntax errors
• helps you debugging errors like DNS lookup limit reached
• it also lets you test a new SPF strings before applying it. This can save you time as you don't have to loop with operations

Also the advanced check at vamsoft.com has a very good interface to test new SPF policies.

If you're responsible for gatekeeping in a projects, here is a guide, what to do.
In order to reduce the number of rejects we get from clients, we want to review all code written before it goes to the staging server.

Note: This process is tailored to our specific needs and tools at makandra. While it will certainly not apply to all (especially larger teams), we think it is a helpful starting point.

First, read the [Gatekeeping for developers](https://makandracards.com/makandra/6579-gatekeeping-guide-for...

Most of our CI pipelines don't use the --retry flag for Cucumber and instead build their own retry via the tmp/failing_features.txt file.

Benefits:

• It's possible to only use -f pretty for the rerun.

Drawbacks:

• MAJOR: With our current setup, when the main run fails without writing a tmp/failing_features.txt (e.g. due to a syntax error), the CI job will pass
• MINOR: With our current setup, we lose the test coverage of the main run

A fix for the passing CI despite syntax error could look like this:

cucumber:
  # ...
  sc...

tl;dr

In RubyMine you can use find and replace with capture groups (.*?) and backreferences $1 (if you have several groups: $[Capture-Group ID]).
Named captures (?<text>.*) are also supported.

Examples

Replace double quotes with single quotes

If you want to replace double quotes with single quotes, replacing every " with a ' is prone to errors. Regular expressions can help you out here.

1. Open find and replace
2. Activate the regex mode (click on the .* icon next to the "find" field).
3. Fill in f...

Whenever you have to deal with randomness in a jasmine test there are some spy strategies to help you out!

Let's say we have a method Random.shuffle(array) to shuffle an array randomly and a class that uses shuffle within the constructor.

returnValue & returnValues

it('shuffles the array', () => {
  spyOn(Random, 'shuffle').and.returnValue([3, 2, 1])
  array = [1, 2, 3]
  
  testedClass = new testedClass(array)
  
  expect(Random.shuffle).toHaveBeenCalled()
  expect(testedClass.array).toEqual([3, 2, 1])
})

If you have...