kddnewton

Faster Rails tests

Feedback loop speed in one of the biggest contributing factors to overall development time. The faster you get results, the faster you can move on to other things. A fast enough test suite is therefore critical to teams' success, and is worth investing some time at the beginning to save in the long run.

Below is a list of techniques for speeding up a Rails test suite. It is not comprehensive, but should definitely provide some quick wins. This list of techniques assumes you're using minitest, but most everything should translate over to rspec by simply replacing test/test_helper.rb with spec/spec_helper.rb.

• Lead with data
• bcrypt
• bootsnap
• Cache Time::utc calls

kddnewton

# frozen_string_literal: true

class Number
  SIZE = 32

  attr_reader :values

  def initialize(values = [0])
    @values = values
  end

kddnewton

# frozen_string_literal: true

class Context < BasicObject
  def method_missing(name, *) = :identifier
  def self.const_missing(name) = :constant
end

$context = Context.new

def evaluate(encoding, codepoint)

kddnewton

import * as prism from "@ruby/prism";

class RubyInteger {
  constructor(value) {
    this.value = value;
  }

  _plus(other) {
    if (!(other instanceof RubyInteger)) {
      throw new TypeError(`no implicit conversion of ${other.constructor.name} into Integer`);

kddnewton

require "json"

struct = { "a" => 1, "b" => 2, "c" => [1, 2, 3], "d" => [{ "e" => 3 }, nil, false, true, [], {}] }
source = JSON.dump(struct)

tokens = []
index = 0

until source.empty?
  tokens <<

kddnewton

# frozen_string_literal: true

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"
  gem "activerecord", "~> 7.0.0"
  gem "sqlite3"
end

kddnewton

require "yarp"

module YARPAST
  def yarp_ast
    ast =
      begin
        RubyVM::AbstractSyntaxTree.of(self, keep_script_lines: true)
      rescue ArgumentError
      end

kddnewton

#include <stdbool.h>
#include <stddef.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>

// Each entry in this lookup table indicates whether a character is a valid

kddnewton

# frozen_string_literal: true

require "bundler/inline"

gemfile do
  source "https://rubygems.org"
  gem "json_pure"
  gem "benchmark-ips"
end

kddnewton

putspecialobject 3
putnil
defineclass :FooBar, 0
  definemethod :foo
    putobject "FooBar#foo"
    leave

  definemethod :bar
    putobject "class variable"
    setclassvariable :@@bar