Dave Doolin doolin

You MUST NOT try and generate a Rails app from scratch on your own by generating each file. For a NEW app you MUST use rails new first to generate all of the boilerplate files necessary.
Create an app in the current directory with rails new .
Use Tailwind CSS for styling. Use --css tailwind as an option on the rails new call to do this automatically.
Use Ruby 3.2+ and Rails 8.0+ practices.
Use the default Minitest approach for testing, do not use RSpec.
Default to using SQLite in development. rails new will do this automatically but take care if you write any custom SQL that it is SQLite compatible.
An app can be built with a devcontainer such as rails new myapp --devcontainer but only do this if requested directly.
Rails apps have a lot of directories to consider, such as app, config, db, etc.
Adhere to MVC conventions: singular model names (e.g., Product) map to plural tables (products); controllers are plural.
Guard against incapable browsers accessing controllers with `allo

Falsehoods programmers believe about time

This is a compiled list of falsehoods programmers tend to believe about working with time.

Don't re-invent a date time library yourself. If you think you understand everything about time, you're probably doing it wrong.

Falsehoods

There are always 24 hours in a day.
February is always 28 days long.
Any 24-hour period will always begin and end in the same day (or week, or month).

This is a very quick gist I'm throwing together to get this info and discussion onto google in one place.

For years, people have been using jemalloc with ruby. There are various benchmarks and discussions. Some people say Jemalloc 5 doesn't work as well as Jemalloc 3.

Then, one day, hope appeared on the horizon. Someone offered a config for Jemalloc 5.

The recipe would be something like this (shown with official docker ruby image). I didn't try this yet, don't know if it will build!

	class Tree
	attr_reader :val, :left, :right

	def self.empty
	EmptyTree.new
	end

	def self.leaf(val)
	new(val, empty, empty)
	end

	# need to "pin" the variable, but this only works with the lambda because
	# pattern matching falls back to case matchint (=== on any object in ruby,
	# which is NOT "identical object" as in JS)
	def matches1(pat,x)
	case x
	in ^pat
	puts true
	else
	puts false
	end

	require "openssl"
	require "digest"

	def aes128_cbc_encrypt(key, data, iv)
	key = Digest::MD5.digest(key) if(key.kind_of?(String) && 16 != key.bytesize)
	iv = Digest::MD5.digest(iv) if(iv.kind_of?(String) && 16 != iv.bytesize)
	aes = OpenSSL::Cipher.new('AES-128-CBC')
	aes.encrypt
	aes.key = key
	aes.iv = iv

	require 'openssl'
	require 'base64'
	require 'rexml/document'

	class PKeyRSAConverter
	def initialize(from_pem: nil, from_xml: nil)
	@from_pem = from_pem
	@from_xml = from_xml
	end

	#!/usr/bin/ruby
	require 'openssl'

	TYPES = {
	6 => {magic: 'RSA1', private_key: false},
	7 => {magic: 'RSA2', private_key: true}
	}

	data = ARGV[0] ? File.binread(ARGV[0]) : $stdin.binmode.read
	type, version, algo, magic, bits, rest = data.unpack('ccx2l<a4l<a*')

	# the new and improved one-file rails app -- now including

	require "action_controller/railtie"

	class Tester < Rails::Application
	config.session_store :cookie_store, :key => '_rails_session'
	config.secret_token = '095f674153982a9ce59914b561f4522a'
	end

	class UsersController < ActionController::Base