bensheldon

In my application every time I send a newsletter to a User, I create a NewsletterDelivery record. I frequently want to be able to query, for each user, what is the most recent newsletter delivery record. This is called a "last n per group" query and a LATERAL JOIN is the best way to do it imo. But the query I've been using (and I've told people to use, and seen blogged about) is not very good, because the conditions don't get pushed down into the subselect which means that the query ends-up lateral-joining all the records before it applies the conditions for the association.

Instead of doing subselect_table.* the better query does association.id AS assocation_id, subselect_table.id, subselect_table.title, .... and enumerates over all of the columns. This allows the association query, which Active Record tacks on at the end as WHERE association_id = $1 or WHERE association_id IN ($1, $2, $3, ...) to be pushed down c

sindresorhus

Pure ESM package

The package that linked you here is now pure ESM. It cannot be require()'d from CommonJS.

This means you have the following choices:

1. Use ESM yourself. (preferred)
   Use import foo from 'foo' instead of const foo = require('foo') to import the package. You also need to put "type": "module" in your package.json and more. Follow the below guide.
2. If the package is used in an async context, you could use await import(…) from CommonJS instead of require(…).
3. Stay on the existing version of the package until you can move to ESM.

fractaledmind

require 'date'

class Sorter
  def initialize(*instructions)
    @defaults = {
      direction: :ascending,
      nils: :small,
      accessor: :itself,
      case_sensitive: true,
      normalized: false,

jonleighton

# This hack is designed to prevent a thread from implicitly checking out an AR connection by
# just accessing ActiveRecord::Base.connection. The point of doing this is to ensure that threads
# don't tie up connections that they are not using, by making sure we're explicit about where we
# need to use an AR connection.
#
# See also http://tenderlovemaking.com/2011/10/20/connection-management-in-activerecord.html

ActiveSupport.on_load(:active_record) do
  ActiveRecord::ConnectionAdapters::ConnectionPool # ensure loaded

mperham

I want to build a system which uses rules. These rules will change hourly (i.e. "this rule is effective from 2pm to 6pm"). The rules must support arbitrarily complex logic on just 2-3 pre-defined variables and result in a boolean:

item.a > 10 && item.b == 0 || item.category == FOOTWEAR

These rules will be executed hundreds of times per second so I can't afford the overhead of plain old eval. I want to reload the current effective ruleset from the database hourly, precompile each rule's logic string and execute it via the quickest method possible. It might look something like this:

class Rule

seanknox

module CapybaraHelpers
  class << self
    def local_ip
      ipv4_addr_info.ip_address
    end

    def setup_selenium_remote
      app_host ||= ENV.fetch('SELENIUM_APP_HOST', local_ip)
      Capybara.server_host = app_host
      Capybara.app_host = "http://#{app_host}:#{Capybara.current_session.server.port}"

hadees

module Capybara::Poltergeist
  class Client
    private
  def redirect_stdout
    prev = STDOUT.dup
    prev.autoclose = false
    $stdout = @write_io
    STDOUT.reopen(@write_io)

    prev = STDERR.dup

radar

Rails 4 Differences

Chapter 1

No differences.

Chapter 2

• root :to => "dashboard#index" is now root "dashboard#index"`
• Need to permit parameters within Subscribem::AccountsController

dypsilon

Frontend Development

Attention: the list was moved to

https://github.com/dypsilon/frontend-dev-bookmarks

This page is not maintained anymore, please update your bookmarks.

---

tovodeverett

RSpec.configure do |config|
  config.before(:suite) do
    DatabaseCleaner.clean_with(:truncation)
  end

  config.before(:each) do
    DatabaseCleaner.strategy = Capybara.current_driver == :rack_test ? :transaction : :truncation
    DatabaseCleaner.start
  end