chancejs/chancejs
Chancejs
Chance is a JavaScript library for generating random data, designed to produce realistic test data for automated tests and prototypes. It uses a Mersenne Twister pseudo-random number generator that accepts an optional seed value, enabling reproducible sequences of random values across multiple runs.
The library provides a wide range of generators for common data types, including random integers, floats, booleans, characters, strings, and dates, all with configurable ranges and character pools. It can generate realistic geographic data like addresses, as well as financial data such as credit card numbers that pass the Luhn algorithm, currency pairs, and formatted monetary amounts. Chance also supports picking random items or subsets from arrays and generating random names and email addresses.
The library is extensible, allowing users to attach custom generator functions and override built-in datasets to adapt random generation to specific contexts. Its method-chaining API enables sequential calls in a single expression, and locale-aware formatting is available for region-specific output like euro amounts.
Features
- Random Identifier Generators - Generates strings of random characters with configurable length and an optional custom character pool.
- Random Number Generator Seeding - Accepts an optional seed value to produce identical sequences of random values across multiple runs.
- Seedable Generators - Accepts an optional seed to produce deterministic pseudo-random sequences for reproducibility.
- Configurable Random Utilities - Generates random booleans, integers, floats, dates, and characters with configurable ranges and pools.
- Random Data Utilities - Provides configurable random generation for booleans, integers, floats, dates, and more.
- Random Data Generators - Generates random strings, numbers, names, and addresses for use in automated tests and prototypes.
- Realistic Data Generators - Generates realistic random strings, numbers, names, and addresses for automated tests and prototypes.
- Test Data Generators - Creates realistic random test data including names, addresses, and credit card numbers.
- String and Character Generators - Generates random strings, characters, and letters with configurable pools alongside numeric values.
- Unbiased Random Integer Generators - Returns whole numbers within a specified inclusive range, defaulting to the full JavaScript integer range.
- Reproducible Randomizers - Uses a seeded Mersenne Twister to produce deterministic random sequences for reproducible tests.
- Mersenne Twister Implementations - Uses a Mersenne Twister pseudo-random number generator for high-quality, reproducible random sequences.
- Random Number Generation - Generates random integers and floats within specified ranges using a Mersenne Twister algorithm.
- Random Number Generators - Returns true or false with a configurable likelihood, defaulting to a 50% chance of true.
- Range-Bounded Random Generators - Produces random numbers within inclusive minimum and maximum bounds for integers, floats, and primes.
- Character Randomization - Provides configurable character pools for generating random characters from alphabetic, alphanumeric, or symbol sets.
- Synthetic Address Generators - Generates realistic synthetic street addresses, cities, and postal codes for geographic test data.
- Collection Randomization Utilities - Selects a single random element from an array or array-like collection.
- Email Address Generators - Creates random email addresses with realistic username and domain patterns for test data.
- Custom Generator Extensions - Provides an extensibility API for attaching custom generator functions and overriding built-in datasets.
- Random Date & Time Generators - Produces random dates within configurable ranges for test data generation.
- Random Identifier Generators - Generates realistic random first names, last names, and full names for test data.
- Random Sampling - Ships a method to pick random items or subsets from arrays for sampling workflows.
- Credit Card Generators - Generates random credit card numbers that pass the Luhn algorithm, optionally specifying the card type.
- Luhn Algorithm Validators - Generates credit card numbers that pass the Luhn checksum for realistic test data.
- Random Value Generators - Produces random boolean values with configurable weighting for test inputs.
- Subset Generators - Returns a random subset of elements from an array without replacement.
- Randomized Selection - Selects a single random element from a provided array.
- Number Utilities - Generating random numbers and strings.
- Numeric Utilities - Generates random numbers and strings.
