Chrome is now kept from opening PDF downloads. It will stay on the current page.

Updated for recent versions of Chrome, which do not have a "remote debugging address" and only listen on localhost.

To disable the mostly useless automatic suggestion popups in RubyMine, go to File / Settings, then to Editor / General / Code Completion and uncheck Auto-display code completion.

You can still open the popup by pressing CTRL + Space. And you probably want to use Context-dependent word expansion instead, anyway.

When you are working with SVG files and ImageMagick you can get different results on different machines depending on which additional packages you have installed.

From: http://www.imagemagick.org/script/formats.php

ImageMagick utilizes inkscape if its in your execution path otherwise RSVG. If neither are available, ImageMagick reverts to its internal SVG renderer.

In interactive commands, Git allows the user to provide one-letter input with a single key without hitting enter (docs).

# Enabled this feature globally
git config --global interactive.singlekey true

# Or enable this feature locally for a single repository
git config interactive.singlekey true

This allows you to hit "y" instead of "y + ENTER" to move to the next hunk.

Stage this hunk [y,n,q,a,d,s,e,?]?

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...

Back in the war, Rails developers had to manually HTML-escape user-supplied text before it was rendered in a view. If only a single piece of user-supplied text was rendered without prior escaping, it enabled XSS attacks like injecting a <script> tag into the view of another user.

Because this practice was so error-prone, the rails_xss plugin was developed and later integrated into Rails 3. rails_xss follows a different approach: Instead of relying...

When you need to create a locale for a language variant (like Austrian for German), you probably don't want to duplicate your entire de.yml file only to change a few minor exceptions for our Austrian friends.

Luckily, the I18n gem used by Rails has a fallback feature where you can make one locale file fall back to another if no translation is available.

In the example above you would have a config/locales/de_DE.yml:

de_DE:
  # hundreds of translations here

... and another lo...

When an AJAX request raises an exception on the server, Rails will show a minimal error page with only basic information. Because all Unpoly updates work using AJAX requests, you won't get the more detailled better_errors page with the interactive REPL.

Below is an event listener that automatically repeats the request as a full-page load if your development error shows an error page. This means you get...

When using Sidekiq in your application, you must write thread-safe code.

This wiki page also lists gems that are known to be unsafe on threaded applications.
When adding a gem that will also be used by a Sidekiq worker, make sure to confirm it's thread-safe.

I often see the use of || to set a default value for a variable that might be nil, null or undefined.

x = x || 'default-value'

This pattern should be avoided in all languages.

While using || works as intended when x is null or an actual object, it also sets the default value for other falsy values, such as false. false is a non-blank value that you never want to override with a default.

To make it worse, languages like JavaScript or Perl have [many more fal...

Proxy caching is a good feature to serve your publicly visible application content faster and reduce load on your servers. It is e.g. available in nginx, but also affects proxies delivered by ISPs.

Unfortunately, there is a little problem in Rails < 6.1 when delivering responses for different MIME-types. Say you have an arbitrary route in your Rails application that is able to respond with regular HTML and JSON. By sending the specific MIME type in the Accept header, you tell the application to either return HTML (text/html) or JSON (`t...

To reverse lookup a fixture by its table name and id, use the following approach on ActiveRecord::FixtureSet:

table = 'users'       # Specify the fixture table name
id = 123122           # Specify the ID to look for

# Find the fixture that matches the given ID
ActiveRecord::FixtureSet.all_loaded_fixtures[table].fixtures.find { |key, value| value['id'] == id }

Result Example:

[
  "one", # Fixture name
  #<ActiveRecord::Fixture:0x00007e79990234c8>, # ActiveRecord::Fixture object
  @fixture= { ... }, # The raw fixtu...

I tried to make it easier to read how to set the sass options for the different build tools.

Updated for selenium-webdriver 4.27 which requires options.add_option(:page_load_strategy, 'none').

Your package-lock.json should always match and resolve all packages from your package.json.
Coming from Yarn, I was looking for an option like Yarn's --frozen-lockfile which validates that. Here is what seems to be the way to do it.

Using npm clean-install

Running npm clean-install instead of npm install will actually validate that your package-lock.json matches your package.json.

You can use npm ci as a shortcut for npm clean-install.

Combine with a cache

The idea of a "clean install" is that it always install...

Warning

safe_constantize is not safe for unfiltered user input

In Rails, the safe_constantize method is a powerful tool that helps developers safely convert strings into constants. This feature is particularly useful in scenarios where constant lookup might fail or could potentially introduce security risks. Let’s dive into what safe_constantize is, how it works, and why you should use it.

What Is safe_constantize?

The `safe_cons...

In development, we store files using ActiveStorage's disk service. This means that stored files are served by your Rails application, and every request to a file results in (at least!) one non-trivial log entry which can be annoying. Here is how to disable those log entries.

Example

Here is an example of what loading a single <img> in an example application writes to the Rails log.

Started GET "/rails/active_storage/blobs/redirect/..." for ::1 at ...
Processing by ActiveStorage::Blobs::RedirectController#show as SVG
  Parameter...

If you update Selenium regularly, you'll run into deprecation warnings similar to:

WARN Selenium [:clear_local_storage] [DEPRECATION] clear_local_storage is deprecated and will be removed in a future release

You can ignore this deprecation warning and clean your logs with logfilters:

Selenium::WebDriver.logger.ignore(:clear_local_storage)

Just specify the tag (:clear_local_storage) you want to ignore.

When you have a string containing umlauts which don't behave as expected (are not matched with a regexp, can't be found with an SQL query, do not print correctly on LaTeX documents, etc), you may be encountering umlauts which are not actually umlaut characters.

They look, depending on the font, like their "real" umlaut counterpart:

• ä ↔ ä
• ö ↔ ö
• ü ↔ ü

However, they are not the same:

'ä' == 'ä' # false
'ä'.size # 1
'ä'.size # 2

Looking at how those strings are constructed reveals what is going on:

'ä'.unpack('U*...

Rails migrations allow you to use a change method whose calls are automatically inverted for the down path. However, if you need to some path-specific logic (like SQL UPDATE statements) you can not define up and down methods at the same time.

If you were to define define all 3 of them, Rails would only run change and ignore up and down. However, Rails 4+ features a helper method called reversible:

class MyMigration < ActiveRecord::Migration

  def cha...

RubyMine allows bookmarking lines of code. This is super-helpful when working on a complex problem.
I've been using this feature for a few years now, and so should you! :)

Here are the default Linux/Windows keystrokes. See the documentation for other keybindings.

Add an anonymous bookmark

F11

A gray checkmark will be shown in the gutter on the left.
If you press F11 again on a bookmarked line, the bookmark will be removed.

Add a named bookmark ("mnemonic")

Ctrl ...

tl;dr

When a cookie includes an Expires attribute or an HTTP response includes caching headers like Expires or Cache-Control, their validity depends on the server's Date header if present. Otherwise, the browser uses its local time. This can lead to issues in tests with mocked time or inconsistent cache behavior.

Cookie Expires depends on the Date header or browser time

When a cookie includes an Expires attribute, the browser evaluates the expiration date relative to a reference time:

1. If the HTTP response ...

In FactoryBot factories, Rails' file_fixture is not available by default. To enable it, include a support module from rspec-rails:

FactoryBot::SyntaxRunner.include(RSpec::Rails::FileFixtureSupport)

That includes ActiveSupport::Testing::FileFixtures, where file_fixture is defined, but also configures the file_fixture_path so that you can actually use file_fixture.