...binary file. This method might be telling the truth most of the time. But sometimes it doesn't, and that's what causes pain. The method is defined as follows...
...not guaranteed to be 100% accurate. It performs a "best guess" based # on a simple test of the first +File.blksize+ characters. # # Example: # # File.binary?('somefile.exe') # => true # File.binary?('somefile.txt') # => false #--
...text right next to the code: notes for other developers, and for your future self. You can imagine comments as post-its (or sometimes multi-sheet letters ...) on real-world...
...objects like cupboards, light switches etc. As always, with power comes responsibility. Code comments can go wrong in many ways: they may become outdated, silently move away from the code...
...animate HTML elements using the Web Animation API's method .animate(keyframes, options) (which seems to be Baseline for all browsers since 2022). const fadeIn = [{ opacity: 0 }, { opacity: 1 }] // this...
// the animation object can be used for things like querying timings or state or `pause`, `cancel` the animation animation.pause() animation.play() await animation.finished // do other stuff Even though play...
To return non-HTML responses (like XLS spreadsheets), we usually use the respond_to do |format| format.xls do # send spreadsheet end end This is often, but not always the same...
...one format checks for authorization and the other doesn't. params[:format] is only set when a user explicitly puts a .xls at the end of the URL. The format.xls...
options.add_option(:web_socket_url, true) options.add_option(:page_load_strategy, 'none') # required for selenium-webdriver 4.27+ end Capybara::Selenium::Driver.new(app, browser: :chrome, options: options) In combination with...
...ignore' } (which we recommend setting) any unload alerts will now stay open until handled. Note Selenium-Ruby doesn't allow setting the unhandled prompt behavior to a hash yet. See...
Looking at the source code of the validates_numericality_of validator, it becomes clear that it converts the attribute in question to either an integer or float: if configuration[:only...
...any of your users as this is only broken in the most extreme case shown above...
TL;DR: Rails ships two methods to convert strings to constants, constantize and safe_constantize. Neither is safe for untrusted user input. Before you call either method you must validate...
...the input string against an allowlist. The only difference between the two methods is that unresolvable constants raise an error with constantize, but return nil with safe_constantize. If you...
If you want to play music or sounds from a browser, your choice is to use either Flash or the new tag in HTML5. Each method has issues, but depending...
Can play MP3s or Wave files. Cannot play OGG Vorbis audio. Cannot reliably seek to a given position when playing VBR-encoded MP3s. HTML5 audio Is the future, but...
...any of the gems that GEM depends on. For the example above you would say: bundle update cucumber-rails --conservative If Bundler cannot update due to transitive dependencies, check if...
...for old versions of bundler The options below might be relevant if you're stuck with Bundler < 1.14: Option 1 This will work if all dependencies for the update are...
...want some output. In Rails > 3.1 you have two methods at hand: announce and say_with_time. In the migration: class AddUserToken < ActiveRecord::Migration class User < ActiveRecod::Base; end
add_column :users, :token, :string announce "now generating tokens" User.find_in_batches do |users| say_with_time "For users ##{users.first.id} to ##{users.last.id}" do users.each do |user| user.update_attribute :token...
If you are using our opscomplete.com hosting we can set all environment variables mentioned below for your deployment on request. If you're lucky DO_NOT_TRACK=1 opts...
...are collecting data only after you opt into that. ng analytics --global disable Storybook https://storybook.js.org/docs/configure/telemetry npm run storybook -- --disable-telemetry npm run storybook -- --disable-crash-reports export STORYBOOK...
$number = $length / 1px // => 13 Converting a unit the result of an addition or subtraction between two numbers of different units is expressed in the first member’s unit
...the desired unit: $duration: .21s $duration-in-milliseconds: 0ms + $duration // => 210ms An example is storing a transition duration as CSS custom property to read it from Javascript. By converting the...
...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...
...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...
PostgreSQL's Common Table Expressions (CTEs) can be used to extract sub-queries from bulky SQL statements into a temporary table to be referenced instead. This is most useful to...
...avoid ugly joins or sub-selects. CTEs can be used for SELECT, INSERT, UPDATE or DELETE. Example (from the PostgreSQL docs): WITH regional_sales AS ( SELECT region, SUM(amount) AS...
...can use ETags to allow clients to use cached responses, if your application would send the same contents as before. Besides what "actually" defines your response's contents, your application...
...probably also considers "global" conditions, like which user is signed in: class ApplicationController < ActionController::Base etag { current_user&.id } etag { current_user&.updated_at } end Under the hood, Rails generates...
...default order" of rows in database tables. For instance, when you paginate a result set: When using LIMIT, it is important to use an ORDER BY clause that constrains the...
...result rows into a unique order. Otherwise you will get an unpredictable subset of the query's rows. You might be asking for the tenth through twentieth rows, but tenth...
...you prepare your changelist properly, it directs your reviewer’s attention to areas that support your growth rather than boring style violations. When you demonstrate an appreciation for constructive criticism...
...your reviewer provides better feedback . Make others better: Your code review techniques set an example for your colleagues. Effective author practices rub off on your teammates, which makes your job...
...will tell you if there are any and you should not commit when you see them. So go ahead and switch your editor/IDE to automatically remove them for you.
Note that except for RubyMine, the following changes will remove trailing white-space on all lines, not only those that you changed. While this should not be a...
Simplecov is a code coverage tool. This helps you to find out which parts of your application are not tested. Integrating this in a rails project with rspec, cucumber and...
Add it to your Gemfile and bundle group :test do gem 'simplecov', require: false end Add a .simplecov file in your project root: SimpleCov.start 'rails' do
# 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...
...off. To have database_cleaner work correctly: Add the attached database_cleaner.rb to features/support/ Make sure features/support/env.rb contains the following lines in this order: # features/support/env.rb require 'features/support/database_cleaner' require 'cucumber/rails/active_record' require 'cucumber/rails/world...
If your app does not need to support IE11, you can use most ES6 features without a build step. Just deliver your plain JavaScript without transpilation through Babel or TypeScript...
...and modern browsers will run them natively. Features supported by all modern browsers include: fat arrow functions (() => { expr }) let / const class async / await Promises Generators Symbols Rest arguments (...args)
Splitting up commits makes the process of reviewing often easier, since you can create several merge requests or review every commit one by one. So when you find out that...
...refactoring along the current changes, you can use one of the following processes to split up the changes into several commits in a logical order: #1 Splitting up the last...
Bundler so far ignored the version specified under BUNDLED_WITH in the Gemfile.lock. This had two annoying consequences: If the bundler version on your system was lower than in the...
...and had to manually install the correct version. If the bundler version on your system was higher than in the Gemfile.lock, bundler silently updated the version in the Gemfile.lock to...
You need to update a lof gems. Make sure you don't have any version constraints in your Gemfile or your bundle update won't do anything!
...cucumber_priority: bundle update cucumber_priority Upgrade spreewald: bundle update spreewald Upgrade cucumber_factory: bundle update cucumber_factory Upgrade parallel_tests: bundle update parallel_tests Even on the latest version...