jaynetics’s gists

jaynetics / script.rb

Created June 27, 2023 17:50

download all comments of a youtube video

	#!/usr/bin/env ruby

	# usage: script.rb <video_id> <api_key>

	require 'json'
	require 'net/http'

	video_id = ARGV[0].tap { \|s\| s&.length&.<(13) \|\| fail('pass video id as first argument') }
	key = ARGV[1].tap { \|s\| s&.length&.>(13) \|\| fail('pass api key as second argument') }
	url = "https://youtube.googleapis.com/youtube/v3/commentThreads?part=snippet&videoId=#{video_id}&key=#{key}"

jaynetics / access_db_matcher.rb

Created June 26, 2023 19:25

test in rspec that a block of code does / does not access the DB

	RSpec::Matchers.define :access_db do
	match do \|actual\|
	# track db access via ActiveRecord instrumentation
	sql_callback = ->(*, event) do
	# ignore automatic schema queries and transactions, though
	@db_event = event unless event[:sql] =~ / a\.\|max_ident\|SAVEPOINT/
	end

	ActiveSupport::Notifications.subscribed(sql_callback, 'sql.active_record') do
	actual.call

jaynetics / regexp_properties_by_ruby_version.rb

Created June 14, 2023 19:15

Show when each regexp unicode property was added to Ruby

	require 'regexp_parser'

	map = Regexp::Syntax.specified_versions.to_h do \|ver\|
	[ver, Regexp::Syntax.const_get(ver).added_features[:property].to_a]
	end
	Regexp::Syntax::CURRENT.features[:property].to_h do \|prop\|
	[prop, map.keys.find { \|v\| map[v]additions.include?(prop) }]
	end

jaynetics / struct2.rb

Created May 30, 2023 18:32

Attempt at overriding Struct subclass ::new in Ruby for better kwargs performance

	Struct2 = Class.new(Struct)
	Struct2.singleton_class.prepend Module.new {
	def new(...)
	st = super
	st.instance_eval <<~RUBY
	alias __orig_new__ new

	ARG_NOT_GIVEN = Object.new.freeze

	def new(#{st.members[0]} = ARG_NOT_GIVEN, , *)

jaynetics / benchmarks.rb

Last active May 25, 2023 12:00

Performance overhead of Ruby TracePoint API

	######
	# Simplest case - one method that does nothing, with and without TP
	######

	require 'benchmark/ips'

	def noop; end

	Benchmark.ips { \|x\| x.report('basic', 'noop') }; 1

jaynetics / find_unused_modules.rb

Created May 4, 2023 17:37

find possibly unused modules in a rails app

	code = Dir['{app,config,lib}/*/.{rb,slim,erb,rake}'].map { File.read _1 }.join; 1
	defs = code.scan(/(?:class\|module) \K[A-Z][\w:]+(?=\n)/); 1
	refs = code.scan(/(?<!class \|module )\b#{Regexp.union(defs + defs.map { \|d\| d.split('::').last })}\b/); 1
	unused = defs.uniq.sort.select { \|d\| refs.count(d) == 0 && refs.count(d.split('::').last) == 0 }

jaynetics / hash_new_vs_dup.rb

Created February 27, 2023 10:52

Ruby benchmark for making empty, compare_by_identity Hash with new / literal vs dup

jaynetics / case_vs_hash.rb

Created February 22, 2023 14:24

Ruby benchmark of symbol lookup in case statement vs Hash

jaynetics / weak_ref_registry.rb

Created January 15, 2023 10:27

A self-cleaning weak-ref registry to retrieve object instances by their object_id in Ruby

	# This allows doing
	#
	# Foo.prepend(WeakRefRegistry)
	#
	# foo = Foo.new # => #<Foo:0x1>
	# foo_id = foo.object_id # => 1234
	# Foo.registry.fetch(foo_id) # => #<Foo:0x1>
	#
	# I.e. retrieve Foo instances by their object_id,
	# without affecting garbage collection.

jaynetics / case_vs_equal.rb

Created December 30, 2022 09:22

Benchmark for Ruby case statement vs ==, eql?, equal?

	code = Dir['{app,config,lib}/*/.{rb,slim,erb,rake}'].map { File.read _1 }.join; 1
	defs = code.scan(/(?:class\|module) \K[A-Z][\w:]+(?=\n)/); 1
	refs = code.scan(/(?<!class \|module )\b#{Regexp.union(defs + defs.map { \|d\| d.split('::').last })}\b/); 1
	unused = defs.uniq.sort.select { \|d\| refs.count(d) == 0 && refs.count(d.split('::').last) == 0 }

Janosch Müller jaynetics