Faker 
Generate (almost) realistic fake data for testing, demos, and populating your database during development.
Quick links
Features
- Internet: Email addresses, Passwords, Domains, etc.
- Date and Time: Travel back in time or to the future.
- Person: Names, Genders, Bios, Job titles, and more.
- Number and String: Random numbers and strings.
- Location: Addresses, Zip Codes, Street Names, States, and Countries.
- Finance: Account Details, Transactions, and Crypto Addresses.
- Localization - Customize faker with over 40 locales to generate realistic-looking Names, Addresses, and Phone Numbers.
Note: The generated names, addresses, emails, phone numbers, and/or other data might return valid information. Please be careful when using faker in your tests.
For a complete list of the generators, see Generators.
Getting Started
Start by including faker in your Gemfile:
gem 'faker'
Then run bundle install.
Usage
require 'faker'
Faker::Name.name #=> "Christophe Bartell"
Faker::Internet.password #=> "Vg5mSvY1UeRg7"
Faker::Internet.email #=> "[email protected]"
Faker::Address.full_address #=> "5479 William Way, East Sonnyhaven, LA 63637"
Faker::Markdown.emphasis #=> "Quo qui aperiam. Amet corrupti distinctio. Sit quia *dolor.*"
Faker::Lorem.paragraph #=> "Recusandae minima consequatur. Expedita sequi blanditiis. Ut fuga et."
Faker::Alphanumeric.alpha(number: 10) #=> "zlvubkrwga"
Faker::ProgrammingLanguage.name #=> "Ruby"
Table of Contents
Notes
- While Faker generates data at random, returned values are not guaranteed to be unique by default. To explicitly specify when you require unique values, see Ensuring Unique Values.
- Values also can be deterministic if you use the deterministic feature, see Deterministic Random.
- This is the
main branch of Faker and may contain changes that are not yet released. The list of all versions is available here.
Ensuring unique values
To ensure Faker generates unique values, prefix your method call with unique:
Faker::Name.unique.name # This will return a unique name every time it is called
If too many unique values are requested from a generator that has a limited
number of potential values, a Faker::UniqueGenerator::RetryLimitExceeded
exception may be raised. It is possible to clear the record of unique values
that have been returned, for example between tests.
Faker::Name.unique.clear # Clears used values for Faker::Name
Faker::UniqueGenerator.clear # Clears used values for all generators
You can also give some already-used values to the unique generator if you have
collisions with the generated data (i.e., using FactoryBot with random and
manually set values).
# Faker::<generator>.unique.exclude(method, arguments, list)
# Add 'azerty' and 'wxcvbn' to the string generator with 6 char length
Faker::Lorem.unique.exclude :string, [number: 6], %w[azerty wxcvbn]
Deterministic Random
Faker supports seeding of its pseudo-random number generator (PRNG)
to provide deterministic output of repeated method calls.
Faker::Config.random = Random.new(42)
Faker::Lorem.word #=> "velit"
Faker::Lorem.word #=> "quisquam"
Faker::Config.random = Random.new(42)
Faker::Lorem.word #=> "velit"
Faker::Lorem.word #=> "quisquam"
Faker::Config.random = nil # seeds the PRNG using default entropy sources
Faker::Config.random.seed #=> 185180369676275068918401850258677722187
Faker::Lorem.word #=> "ipsam"
Localization
You may want Faker to print information depending on your location in the world.
To assist you in this, Faker uses the I18n gem to store strings and formats to
represent the names and postal codes of the area of your choosing.
Just set the locale you want as shown below, and Faker will take care of the rest.
Faker::Config.locale = 'es'
# or
Faker::Config.locale = :es
To override Faker's locales, and set it on threaded server environments
check out the locales README.
Minitest and Faker >= 2.22
To prevent Faker (version >= 2.22) from generating duplicate values when using Minitest,
you might need to add the following to the test_helper.rb or rails_helper.rb file:
Faker::Config.random = Random.new
Generators
To see the full list, check out the GENERATORS document.
Contributing
Note: We are not accepting proposals for new generators and locales. The Contributing guide has a few notes about this decision.
Take a look at the Contributing document for
instructions on setting up the repo on your machine, opening bug reports, understanding the codebase,
and creating a good pull request.
There is a Discord channel to discuss anything
regarding improvements or feature requests. This is not actively monitored by the current maintainers.
Thank you, contributors!
Versioning
Faker follows Semantic Versioning 2.0 as defined at https://semver.org.
Inspiration
Faker was inspired by Perl's Data::Faker library.
License
This code is free to use under the terms of the MIT license.
Faker 是一个 Ruby 库，可以生成看起来很真实的假数据（姓名、地址、电子邮件、电话号码等），用于测试、演示，以及为数据库填充种子数据。