---
title: Previous versions
description: v4 integration packages and their v5 replacements.
---

Use this page when you maintain tests on AutoFixture **4.18.1** or need to map legacy integration packages to v5.

## xUnit.net 2 (v4)

| v4 | v5 |
|----|-----|
| AutoFixture.xUnit2 4.18.1 | [AutoFixture.Xunit3](/docs/integrations/xunit3) 5.0.0-rc.1 |
| AutoFixture.xUnit 4.18.1 | [AutoFixture.Xunit3](/docs/integrations/xunit3) 5.0.0-rc.1 |
| xUnit 2.x | xunit.v3 2.x |

API reference: [/api/xunit2/4-18-1](/api/xunit2/4-18-1)

Before `[AutoData]` attributes, tests often used a manual fixture:

```csharp
var fixture = new Fixture();
var sut = fixture.Create<MyClass>();
var expected = fixture.Create<int>();

var result = sut.Echo(expected);

Assert.Equal(expected, result);
```

## NUnit 2 and 3 (v4)

| v4 | v5 |
|----|-----|
| AutoFixture.NUnit3 4.18.1 | [AutoFixture.NUnit4](/docs/integrations/nunit4) 5.0.0-rc.1 |
| AutoFixture.NUnit2 4.18.1 | [AutoFixture.NUnit4](/docs/integrations/nunit4) (requires .NET 8+) |
| NUnit 3.x | NUnit 4.x |

API reference: [/api/nunit3/4-18-1](/api/nunit3/4-18-1)

Modern equivalent:

```csharp
[Test, AutoData]
public void AutoData_WorksAsStandInForLegacyNUnit3Package(int expectedNumber, MyClass sut)
{
    var result = sut.Echo(expectedNumber);

    Assert.That(result, Is.EqualTo(expectedNumber));
}
```

## Other v4-only packages

| Package | API |
|---------|-----|
| AutoFixture.Idioms.FsCheck 4.18.1 | [/api/idioms-fscheck/4-18-1](/api/idioms-fscheck/4-18-1) |
| AutoFixture.AutoFoq 4.18.1 | [/api/autofoq/4-18-1](/api/autofoq/4-18-1) |
| AutoFixture.AutoRhinoMocks 4.18.1 | [/api/autorhinomocks/4-18-1](/api/autorhinomocks/4-18-1) |

## Related

- [Migrate from v4 to v5](/docs/reference/v4-to-v5-migration)
- [NuGet packages](/docs/reference/packages)
- [Compatibility](/docs/reference/compatibility)