# Bogus — Realistic Fake Data Generator for .NET

> A simple and powerful fake data generator for C#, F#, and VB.NET, based on and compatible with the popular faker.js library.

## Install

Save in your project root:

# Bogus — Realistic Fake Data Generator for .NET

## Quick Use
```bash
dotnet add package Bogus
```
```csharp
var faker = new Faker<User>()
    .RuleFor(u => u.Name, f => f.Name.FullName())
    .RuleFor(u => u.Email, f => f.Internet.Email());
var user = faker.Generate();
```

## Introduction
Bogus is a .NET port of the popular faker.js library, providing a fluent API for generating realistic fake data. It is widely used for seeding databases, populating test fixtures, and prototyping applications without relying on production data.

## What Bogus Does
- Generates fake data across 50+ categories including names, addresses, finance, and lorem text
- Provides a strongly-typed fluent API for defining generation rules per property
- Supports 40+ locales for internationalized fake data
- Produces deterministic output with configurable seed values for reproducible tests
- Works with records, classes, and anonymous types in C#, F#, and VB.NET

## Architecture Overview
Bogus uses a fluent builder pattern where `Faker<T>` maps generation rules to properties via lambda expressions. Under the hood, each data category (Name, Address, Commerce, etc.) is a dataset class loaded from locale-specific JSON files. A Mersenne Twister PRNG with optional seed ensures reproducibility.

## Self-Hosting & Configuration
- Install via NuGet: `dotnet add package Bogus`
- No external services or configuration required — it is a pure library
- Set a seed with `new Faker<T>().UseSeed(1234)` for deterministic output
- Use `Faker.GlobalUniqueIndex` to track unique values across instances
- Add locale-specific data with `new Faker<T>("de")` or any supported locale code

## Key Features
- Fluent API with full IntelliSense support in Visual Studio and Rider
- Over 50 built-in data generators (Phone, Company, Vehicle, Hacker, etc.)
- Supports complex object graphs with nested fakers
- Lightweight with no external dependencies
- Extensively tested with high community adoption across the .NET ecosystem

## Comparison with Similar Tools
- **Faker.js** — The JavaScript original; Bogus is its .NET port with idiomatic C# API
- **AutoFixture** — Focuses on anonymous test data; Bogus produces human-readable realistic data
- **NBuilder** — Object builder for tests; less focus on realistic data categories
- **GenFu** — Simpler .NET fake data library; Bogus has more categories and locales

## FAQ
**Q: Can Bogus generate unique values?**
A: Yes, use the `.UniqueIndex` property or the `f.IndexFaker` to ensure uniqueness across generated instances.

**Q: Does Bogus work with Entity Framework?**
A: Yes, it is commonly used in EF Core seed methods to populate databases with test data.

**Q: How do I generate a list of fake objects?**
A: Call `faker.Generate(100)` to create a list of 100 fake objects in one call.

**Q: Is Bogus suitable for production use?**
A: It is designed for testing, development, and demos — not for generating production data.

## Sources
- https://github.com/bchavez/Bogus
- https://www.nuget.org/packages/Bogus

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Source: https://tokrepo.com/en/workflows/asset-a9aad544
Author: AI Open Source