Skip to content

Instantly share code, notes, and snippets.

jjb / code.rb
Created October 4, 2023 16:28
How to set sidekiq options for ActionMailer / ActiveJob / MailDeliveryJob
View code.rb
# in default config, ActionMailer will use sidekiq wrapped in ActiveJob
# This makes it so there is no obvious/direct place to specify configuration
# It's easy to do with the below method, which can be placed in an initializer
Rails.application.config.after_initialize do
ActionMailer::MailDeliveryJob.class_eval do
sidekiq_options retry: 2
jjb / code.rb
Created September 26, 2023 18:09
benchmark ruby rand vs rand(100)
View code.rb
require 'benchmark/ips'
require "benchmark/memory"
Benchmark.ips do |x|"rand") do
end"rand(100)") do
jjb /
Created June 22, 2023 17:48
Shipyard Shell
#!/usr/bin/env sh
# usage
# shipyard-shell 6187 postgres
# shipyard-shell 6187 api
identifier=`shipyard get environments | grep pr$pr | xargs | cut -w -f1` # xargs to remove leading and trailing whitespace
jjb /
Created June 20, 2023 02:15
How to see which rubocop file is being evaluated

If you are in a situation where rubocop is hanging on a file but you don't know which one, afaik there is no way to have rubocop pring each filename as it runs it. None of the formatters do this and there is no verbose mode. Even --debug does not do this.

Here is a hack to (very slowly) invoke rubocop once for each candidate file:

bundle exec rubocop --list-target-files > files.txt
cat files.txt | xargs -L1 -n1 bundle exec rubocop # this works on macos/bsd, use --verbose instead of -t on linux
jjb /
Last active June 13, 2023 17:41
The equivalent of redhat/centos yum whatprovides for debian/ubuntu
apt update
apt install -y apt-file
apt-file update
apt-file find psql
apt-file find bin/psql
apt-file find postgresql.conf
apt-file find --fixed-string convert # equivalent of .*convert.*, way too much
apt-file find --fixed-string /usr/bin/convert # need to know exact path
apt-file find --regexp '.*bin/convert$' # bingo. would also pick up .../sbin/
jjb / file.rb
Created May 13, 2023 01:36
in MacOS, temporarily set the clipboard to something, and then set it back, using ruby
View file.rb
`echo '#{ENV['THE_TEXT']}' | pbcopy`
3.downto(0) do |second|
`osascript -e 'display notification "Reseting clipboard in #{second} seconds" with title "TMP Clipboard"'`
sleep 1
`echo '#{old}' | pbcopy`
jjb /
Last active November 27, 2023 12:39
Using Jemalloc 5 with

For years, people have been using jemalloc with ruby. There are various benchmarks and discussions. Legend had it that 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).

FROM ruby:3.1.2-bullseye
jjb / 1
Last active March 7, 2023 05:15
wrapper script for starting ruby with configured jemalloc
View 1
jjb /
Created September 25, 2022 02:44
markdown indentation demo
  1. hello
  2. hello
    1. nested
    2. nested
      1. more
      2. more
        1. and again
          puts "hello"
View Notes on rails reloader and
  • runner does not use executor in <7, does use it in >=7
  • console does not use executor in <7, not sure about >=7