...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...
...paths (including new files), 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...
Debouncing a method call delays its execution until after a specified time has passed. If it's called again before that time has passed, its execution is delayed again.
...would be run more often than it needs to. One example for that are scroll event handlers in JavaScript: You want to react to a user scrolling, but it's...
...or ::1 (IPv6) can only be reached from your own PC: Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port Process tcp LISTEN...
...address 0.0.0.0 can be reached from other PCs on your network: Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port Process tcp LISTEN...
...for file uploads. CarrierWave has an integrated processing mechanism for different file versions with support for ImageMagick through CarrierWave::MiniMagick (which requires the mini_magick gem). In case your processing...
...runs into an error, CarrierWave will just swallow it and rethrow an error with a very generic message like Processing failed. Maybe it is not an image? which does not...
Applications often show or hide elements based on viewport dimensions, or may have components that behave differently (like mobile vs desktop navigation menus). Since you want your integration tests to...
...behave consistently, you want to set a specific size for your tests' browser windows. Using WebDriver options / Chrome device metrics For Google Chrome, the preferred way is setting "device metrics...
Capybara-screenshot can automatically save screenshots and the HTML for failed Capybara tests in Cucumber, RSpec or Minitest. Requires Capybara-Webkit, Selenium or poltergeist for making screenshots. Screenshots are saved...
...into $APPLICATION_ROOT/tmp/capybara. Manually saving a page Additionally you can trigger the same behavior manually from the test using Capybara::Session#save_and_open_page and Capybara::Session#save_screenshot...
Because your examples should not change global state, you should not need to care about the order in which RSpec processes your .rb files. However, in some cases you might...
...rb files in alphabetical order of their file paths by default (or when you specify --order defined). You run tests in random order by using --order random on the command...
When RSpecs runs the first feature spec, you may see log output like this: Capybara starting Puma... * Version 6.5.0, codename: Sky's Version * Min threads: 0, max threads: 4
...on http://127.0.0.1:39949 You can disable this behavior by tweaking Capybara's Puma server in your spec/support/capybara.rb: Capybara.server = :puma, { Silent: true } Note You don't need to configure this...
...pretty_print method As an example, consider the following class. class MyClass # ... def inspect "#<#{self.class} attr1: #{attr1.inspect}, attr2: #{attr2.inspect}>" end end Instances of that class will inspect like #<MyClass attr1...
...Alice", attr2: "Bob">, but IRB will apply a single color (green) for everything. That is because MyClass implements only inspect. If it were to implement pretty_print, IRB would use...
...with two matchers that test for equality. The first is toBe: expect(first).toBe(second) toBe passes when first === second. Unfortunately this is useless for non-primitive values because JavaScript...
...is a horrible language. However, Jasmine comes with another matcher toEqual: expect(first).toEqual(second) This matcher behaves as a human would expect for types like the following: Arrays
This card is a short summary on different ways of assigning multiple attributes to an instance of a class. Using positional parameters Using parameters is the default when assigning attributes...
...It works good for a small number of attributes, but becomes more difficult to read when using multiple attributes. Example: class User def initialize(salutation, first_name, last_name, street...
Detecting if a Javascript is running under Selenium WebDriver is super-painful. It's much easier to detect the current Rails environment instead. You might be better of checking against...
...the name of the current Rails environment. To do this, store the environment name in a data-environment of your . E.g., in your application layout: <html data-environment=<%= Rails.env %>>
...files. Those can be used to apply to a different repository [1] or by someone else (e.g. sent when sent to them via e-mail). Creating a patch in git...
...changes and commit them. Run git format-patch COMMIT_REFERENCE to convert all commits since the referenced commit (not including it) into patch files. For example, let's say you...
You can do so much more than console.log(...)! See the attached link for a great breakdown of what the developer console can give you. Some of my favorites: console.log takes...
E.g. console.log("Current string:", string, "Current number:", 12) Your output can have hyperlinks to Javascript objects E.g. console.log("Check out the current %o, it's great", location)
...Mocking the time zone You can't really change the local time zone of the Selenium-controlled browser. What you can do is change the time zone of the process...
...setting this from an individual test, since you don't know whether or not the Selenium-controlled browser has already launched. Note that we have only tested this with a...
...notice that the records you create are not deleted and will bleed into your specs the next time you run them. You probably have DatabaseCleaner configured to take care of...
...not bloating your test database with old records: RSpec.configure do |config| config.before(:suite) do DatabaseCleaner.clean_with(:deletion) end config.before(:each) do DatabaseCleaner.strategy = :transaction end config.before(:each, transaction: false) do DatabaseCleaner.strategy...
I recently noticed a new kind of flaky tests on the slow free tier GitHub Action runners: Integration tests were running on smaller screen sizes than specified in the device...
...metrics. The root cause was the use of Selenium's page.driver.resize_window_to methods, which by design does not block until the resizing process has settled: We discussed this issue...
...default it allows only accessing visible elements -- when you are using a driver that supports it (e.g. Selenium, not the default Rack::Test driver). Consider the following HTML: One
...true) or find(..., visible: :visible). Note that you could change the default behavior by setting the ignore_hidden_elements config option. However, ignoring invisible elements is a useful default.
CarrierWave comes with some RSpec matchers which will make testing more comfortable. Let's say you have an Uploader like this: class MyUploader < CarrierWave::Uploader::Base include CarrierWave::MiniMagick
...different versions of your uploaded files: version :small do process resize_to_fill: [100, 100] end version :medium do process resize_to_fit: [200, nil] end version :large do
...a global variable in Rails? Ugh, that's the worst. If you need global state, you've probably reached for Thread.current. When you're using Thread.current, you must make sure...
...yourself or your cached data will stay in Thread.current. For Sidekiq, you can use request_store-sidekiq. Cronjobs are unaffected, as a new process is created each time...
When your Rails application server raises error, Capybara will fail your test when it clears the session after the last step. The effect is a test that passes all steps...
...behavior will help you to detect and fix errors in your application code. However, sometimes your application will explode with an error outside your control. Two examples: A JavaScript library...
...just barely wider than the container it should fit into, and it wraps a single word to a new line and it's not really pretty? Cry no more, for...
...in some browsers. When browsers encounter a text-wrapping element with text-wrap: balance style, they will try breaking to a new line sooner, if it balances out the width...
...been released just a few days ago, allowing us to use Webpack 4. I successfully upgraded an existing real-world Webpack 3 application. Below are notes on everything that I...
Note that we prefer not using the Rails asset pipeline at all and serving all assets through Webpack for the sake of consistency. Preparations Remove version locks in Gemfile...
...tough challenge. To get more detailed insights consider using the rack-mini-profiler gem. Setup with Unpoly Add the following gems: group :development do gem 'memory_profiler' gem 'rack-mini...
If you have slow views (Haml/Partials can be slow), consider caching them. Remove code & sql-queries that are not needed to render the page. Calling to_a blindly on...