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...

Like in any language, a FLOAT has complicated semantics for precision. This sometimes causes stored numbers to be slightly off their original value.

Please consider using DECIMAL instead. Decimals have well-defined behavior for rounding and range overflows.

A flaky test is a test that is often green, but sometimes red. It may only fail on some PCs, or only when the entire test suite is run.

There are many causes for flaky tests. This card focuses on a specific class of feature with heavy side effects, mostly on on the UI. Features like the following can amplify your flakiness issues by unexpectedly changing elements, causing excessive requests or other timing issues:

• Lazy loading images
• Autocomplete in search f...

Compatibility: Angular 20+ with Jasmine 5.x and Karma 6.x

As a default Angular CLI auto-generates test bootstrap via angular:test-bed-init via injecting it as a dynamic virtual module.

Custom Bootstrap

Override the main test option in angular.json → projects.{app}.architect.test.options.main: <test entry file> and [then initialize th...

This checklist should help you to check edge cases that are not part of the default Carrierwave configuration.

• Check Default Configuration and Suggested Changes
• Use secret URLs.
• Check if you need expiring public URLs.
• Check if you need an optimized cache
• Use a [nested directory structure](https://makandracards.com/m...

When you are calling a method that may raise an exception that you don't care about, you might think of doing something like the following.

@user = User.something(123) rescue User.new # DON'T

or

@user = begin
  User.something(123)
rescue # DON'T
  User.new
end

This is bad. Do not do that.

You will be rescuing StandardError and all its subclasses, like NameError -- meaning that e.g. a typo in your code won't raise an error...

Jasmine specs that work with DOM elements often leave elements in the DOM after they're done. This will leak test-local DOM state to subsequent tests.

For example, this test creates a <spoiler-text> element, runs some expectations, and then forgets to remove it from the DOM:

describe('<spoiler-text>', function() {
  it ('hides the secret until clicked', function() {
    let element = document.createElement('spoiler-text')
    element.secret = 'The butler did it'
    document.body.appendChild(element)
 ...

The File System Access API is a new capability of modern browsers that allows us to iterate over selected folders and files on a user's machine. Browser support is not great yet, but if the feature is only relevant for e.g. a single admin user it could still be worth using it prior to wider adaption instead of building yet another ZIP upload form.

Below is a simple compiler that i used to evaluate this feature.

!...

Most of the time, it's a good default to add a unique index on the foreign key when using Rails’ has_one relationship. This ensures the database enforces the 1:1 constraint and raises an error if your application logic ever violates it.

class User < ApplicationRecord
  has_one :session, dependent: :destroy
end

class Session < ApplicationRecord
  belongs_to :user
end

create_table :users do |t|
  t.timestamps
end

create_table :sessions do |t|
  t.references :user, null: false, foreign_key: true, index: { unique: true ...

When you have two models in a has_many, has_one or belongs_to association, the :inverse_of option in Rails tells ActiveRecord that they're two sides of the same association.

Example with a has_many / belongs_to association:

class Forum < ActiveRecord::Base
  has_many :posts, inverse_of: :forum
end

class Post < ActiveRecord::Base
  belongs_to :forum, inverse_of: :posts
end

Knowing the other side of the same association Rails can optimize object loading so forum and forum.posts[0].forum will reference the same o...

The problem

Calling bundle update GEMNAME will update a lot more gems than you think. E.g. when you do this:

bundle update cucumber-rails

... you might think this will only update cucumber-rails. But it actually updates cucumber-rails and all of its dependencies. This will explode in your face when one of these dependencies release a new version with breaking API changes. Which is all the time.

In the example above updating cucumber-rails will give you Capybara 2.0 (because capybara is a dependency of `cucumber-rail...

There are two ways to define a class method from a Modularity trait. Note that the usual caveats regarding class method visibility apply.

Using def

You can def the method on self:

module SomeTrait
  as_trait do
    def self.foo
      # ...
    end
  end
end

However, you cannot use it with traits parameters.

Using `define_singleton_met...

Enable local logging for Sentry when:

• Debugging Sentry event capture locally
• Testing error handling without polluting production metrics
• Developing background jobs and want to see what Sentry captures

How to enable

To capture and log Sentry events locally during development without sending to the server, add this to config/initializers/sentry.rb inside the Sentry.init block:

if Rails.env.development?
  # Use dummy transport to prevent actual transmission to Sentry
  config.transport.transport_class = Sentry::DummyTran...

Full-text search can reach its limits in terms of flexibility and performance. In such cases, trigram indexes (pg_trgm) offer a lightweight alternative.

You can base the index on a virtual column that combines multiple text attributes. A stored virtual column stores the result of an expression as if it were a real column. It is automatically updated when the source columns change and can be indexed like normal data. This keeps your query logic consistent and avoids repeating string concatenation in every search.

def searc...

Good reference how to build bootstrap forms with simple_form.

Summary

• Use return to return from a method. return accepts a value that will be the return value of the method call.
• Use break to quit from a block and from the method that yielded to the block. break accepts a value that supplies the result of the expression it is “breaking” out of.
• Use next to skip the rest of the current iteration. next accepts an argument that will be the result of that block iteration.

The following method will serve as an example in the details below:

def example
  puts yield
  puts ...

Database connections are not thread-safe. That's why ActiveRecord uses a separate database connection for each thread.

For instance, the following code uses 3 database connections:

3.times do
  Thread.new do
    User.first # first database access makes a new connection
  end
end

These three connections will remain connected to the database server after the threads terminate. This only affects threads that use ActiveRecord.

You can rely on Rails' various clean-up mechanisms to release connections, as outlined below. This may...

Quick reference for passing data from Rails to JavaScript via Unpoly compilers.

Haml Attribute Syntax

# Ising hash rockets and string symbols (method calls)
= form.text_field :name, 'date-picker': true

# Curly braces or brackets (elements) 
%div.container{ id: 'main', 'data-value': '123' }

Simple Values: data-* Attributes

Use for: Scalar values (IDs, strings, booleans)

%span.user{ 'data-age': '18', 'data-first-name': 'Bob' }

up.compiler('.user', (element, data) => {
  console.log(...

Quick guide for frequently used compiler selector patterns of Unpoly.

1. BEM Component Pattern

When: Reusable UI components with multiple child elements

Examples: toggleable.js, collapsible.js, searchable_select.js

up.compiler('.toggleable', (toggleable) => {
  const checkbox = toggleable.querySelector('.toggleable--checkbox')
  const content = toggleable.querySelector('.toggleable--content')
  // ...
})

%td.toggleable.-inverted.-ignore-when-not-empty
  .toggleable--content
    = form.text_fie...

When starting a project we always make a good estimate of all known requirements, and plan budgets and available developers accordingly.

Requirements change. Budgets usually don't.

To make sure a project stays on track, we update our estimates periodically and compare them to the remaining budget. If this doesn't match any more, we have to act.

To update an estimate, do the following:

• Start with the most recent estimate for the project.
• Which stories have been completed? Set their estimate to zero.
• Have any requirements cha...

To allow HTTP 304 responses, Rails offers the fresh_when method for controllers.

The most common way is to pass an ActiveRecord instance or scope, and fresh_when will set fitting E-Tag and Last-Modified headers for you. For scopes, an extra query is sent to the database.

fresh_when @users

If you do not want that magic to happen, e.g. because your scope is expens...

If you try to listen to events on elements that are nested inside a <fieldset disabled>, Firefox will stop event propagation once the event reaches the fieldset. Chrome and IE/Edge will propagate events.

Since we often bind event listeners to document this can be annoying.

You could solve it by...

• ...adding event listeners on elements themselves. Note that this is terrible when you have many elements that you'd register events for.
• ...adding event listeners on a container inside the <fieldset>, around your eleme...

Performing COUNT(*) on large tables is slow. Sometimes you don’t need the exact number once results exceed a certain threshold.

For example, you may only need to display 100+ in the UI. Using a plain COUNT(*) would scan all matching rows.

The following query would be pretty slow when counting many rows because it has to scan all rows.

SELECT COUNT(*) FROM movies;

Limiting within a subquery

Use a subquery with LIMIT to cap the scan early. ...

When RSpec sets out to print any given object to the console, it will never print more than 200 characters from it. Only the first and last 100 chars from overly long strings are displayed, which sometimes means that the root cause for the failing test is buried in truncation.

For example, I could not easily make out the reason for this failure:

Failure/Error: expect { crawler.pull_new_commits }.not_to raise_error

expected no Exception...