---
title: Introduction
description: AutoFixture creates anonymous test data so you write less arrange code in unit tests.
---

AutoFixture helps you write unit tests with less hand-written setup. A **fixture** creates anonymous values during the arrange phase — strings, nested objects, and the system under test (SUT) — so you can focus on behavior instead of inventing test data.

## In this tutorial

Work through these topics in order:

1. **Introduction** — you are here
2. [Installation](/docs/get-started/installation) — add the NuGet package and verify restore
3. [Your first test](/docs/get-started/first-test) — use `Fixture.Create` in a unit test
4. [Refactoring a test](/docs/get-started/refactoring-a-test) — shrink messy service arrange with AutoMoq and `Build`

## Example scenario

You are testing a `ShippingLabelFormatter` that builds a multi-line label from a customer. The test should verify that the label includes the customer's name and city. You do not care about specific values like `"Jane Doe"` or `"Copenhagen"` — any valid customer is fine.

## Example

```csharp
var fixture = new Fixture();
var customer = fixture.Create<Customer>();
var sut = fixture.Create<ShippingLabelFormatter>();

var label = sut.Format(customer);

Assert.Contains(customer.Name, label);
Assert.Contains(customer.Address.City, label);
```

## How it works

- `new Fixture()` — starts the data generator for this test
- `Create<Customer>()` — builds a `Customer` with an anonymous name and nested `Address`
- `Create<ShippingLabelFormatter>()` — creates the SUT without a manual `new`
- The asserts read from the object graph AutoFixture created, not from hard-coded strings

When constructors or dependencies change, you often change less arrange code than with hand-built objects.

## Example types

The test above uses these types:

```csharp
public class Address
{
    public string Street { get; set; } = string.Empty;
    public string City { get; set; } = string.Empty;
}

public sealed class Customer(string name, Address address)
{
    public string Name { get; } = name;
    public Address Address { get; } = address;
}

public sealed class ShippingLabelFormatter
{
    public string Format(Customer customer) =>
        $"{customer.Name}\n{customer.Address.Street}\n{customer.Address.City}";
}
```

## Next steps

- [Install AutoFixture](/docs/get-started/installation)
- [Write your first test](/docs/get-started/first-test)
- [Refactoring a test](/docs/get-started/refactoring-a-test)
- [Browse the API reference](/api)