JoshCheek

require 'fiddle'

public def to_ptr
  Fiddle::Pointer.new Fiddle.dlwrap self
end

public def to!(klass)
  to_ptr[8, 8] = klass.to_ptr.ref[0, 8]
end

JoshCheek

module Memoize
  NOT_SET = Module.new
  private_constant :NOT_SET

  def memoize(method_name)
    meth = method method_name
    case meth.parameters.map(&:first)
    when [:opt]
      define_method method_name do |arg=NOT_SET|
        _memoizations.fetch arg do

JoshCheek

# https://twitter.com/josh_cheek/status/1421462056994283521
require 'fiddle'
public def address() = Fiddle.dlwrap(self)
public def pointer() = Fiddle::Pointer.new(address)
public def toggle_keywords!() = (pointer[1] ^= 0b100000)

def m(a:) = a

h = {a: 1}
m *[h] rescue $! # => #<ArgumentError: wrong number of arguments (given 1, expected 0; required keyword: a)>

JoshCheek

# Helpers to make the code below easier to read
class Array
  def keywords?()    = Hash.ruby2_keywords_hash?(self[-1])
  def to_keywords!() = (self[-1] = Hash.ruby2_keywords_hash(self[-1]))
end

# Code to facilitate the examples below
def record_args(*args) = args
def call_this(val:)    = val

JoshCheek

# these are Ruby 3's endless methods
require 'pg'
db = PG.connect
def db.exec_params(...) = super.map { |h| h.transform_keys &:intern }
def db.exec(...)        = super.map { |h| h.transform_keys &:intern }

# transactions methods
def db.begin()           = exec('begin')
def db.save(name)        = exec("savepoint #{name}")
def db.rollback_to(name) = exec("rollback to #{name}")

JoshCheek

require 'pg'
$db = PG.connect # to default db

# override the `exec` method so that query results get displayed
def $db.exec(*, **)
  super.map { |r| r.transform_keys &:intern }
end

# A schema with a table in it
def make_schema

JoshCheek

# DB setup
require 'active_record'
ActiveRecord::Base.establish_connection adapter: 'postgresql', database: 'testdb'
ActiveRecord::VERSION::STRING  # => "6.1.3.2"

# Helper method so errors don't kill the program
def show
  yield
rescue StandardError => err
  (err.cause||err).message.lines.first.strip

JoshCheek

class Omghi < ActiveRecord::Migration[6.1]
  def up
    # Some value we want to use in our query, that we don't want to interpolate.
    # The answers on Stack Overflow say to escape this param and then interpolate
    # it into the query, but when I went to OWASP training, they were pretty
    # emphatic that sanitization is inferior to parameterization. I don't 100%
    # know why (it was a giant auditorium, I didn't raise my hand and ask)
    param = 'hello world'

    # By using `exec_query` instead of `execute`, we can pass params.

JoshCheek

# convo: https://twitter.com/dorianmariefr/status/1411306589739433984
# alternative to this: https://gist.github.com/JoshCheek/df6154555387f966ef1808262e38f72e

# We'll ignore everything except required args, to keep it simpler
private def with_types(*ordtypes, name)
  # I guess this works for main, and singleton methods on `self`, but not singleton methods
  owner = is_a?(Module) ? self : method(name).owner
  meth = owner.instance_method(name)

  params = meth.parameters

JoshCheek

# https://twitter.com/dorianmariefr/status/1411306589739433984

# We'll ignore everything except required args, to keep it simpler
private def with_types(*ordtypes)
  mod = is_a?(Module) ? self : Object # to handle edge-case of `main`
  mod.module_eval { @next_types = ordtypes }
end

class Module
  def method_added(name)