Verify

Verify is a snapshot tool that simplifies the assertion of complex data models and documents.

Verify is called on the test result during the assertion phase. It serializes that result and stores it in a file that matches the test name. On the next test execution, the result is again serialized and compared to the existing file. The test will fail if the two snapshots do not match: either the change is unexpected, or the reference snapshot needs to be updated to the new result.

Support is available via a Tidelift Subscription.

Part of the .NET Foundation

Usage
Received and Verified
Videos
Extensions
More Documentation
Alternatives
Security contact information

NuGet packages

Usage

Class being tested

Given a class to be tested:

public static class ClassBeingTested
{
    public static Person FindPerson()
    {
        return new Person
        {
            Id = new Guid("ebced679-45d3-4653-8791-3d969c4a986c"),
            Title = Title.Mr,
            GivenNames = "John",
            FamilyName = "Smith",
            Spouse = "Jill",
            Children = new List<string>
            {
                "Sam",
                "Mary"
            },
            Address = new Address
            {
                Street = "4 Puddle Lane",
                Country = "USA"
            }
        };
    }
}

^{snippet source | anchor}

xUnit

Support for xUnit

using static VerifyXunit.Verifier;

[UsesVerify]
public class Sample
{
    [Fact]
    public Task Test()
    {
        var person = ClassBeingTested.FindPerson();
        return Verify(person);
    }
}

^{snippet source | anchor}

Verify Xunit Intro

NUnit

Support for NUnit

using static VerifyNUnit.Verifier;

[TestFixture]
public class Sample
{
    [Test]
    public Task Test()
    {
        var person = ClassBeingTested.FindPerson();
        return Verify(person);
    }
}

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MSTest

Support for MSTest

[TestClass]
public class Sample :
    VerifyBase
{
    [TestMethod]
    public Task Test ()
    {
        var person = ClassBeingTested.FindPerson();
        return Verify(person);
    }
}

^{snippet source | anchor}

Initial Verification

When the test is initially run will fail with:

First verification. Sample.Test.verified.txt not found.
Verification command has been copied to the clipboard.

The clipboard will contain the following:

cmd /c move /Y "C:\Code\Sample\Sample.Test.received.txt" "C:\Code\Sample\Sample.Test.verified.txt"

Verified result

This will result in the Sample.Test.verified.txt being created:

{
  GivenNames: 'John',
  FamilyName: 'Smith',
  Spouse: 'Jill',
  Address: {
    Street: '4 Puddle Lane',
    Country: 'USA'
  },
  Children: [
    'Sam',
    'Mary'
  ],
  Id: Guid_1
}

^{snippet source | anchor}

Subsequent Verification

If the implementation of ClassBeingTested changes:

public static class ClassBeingTested
{
    public static Person FindPerson()
    {
        return new Person
        {
            Id = new Guid("ebced679-45d3-4653-8791-3d969c4a986c"),
            Title = Title.Mr,
            // Middle name added
            GivenNames = "John James",
            FamilyName = "Smith",
            Spouse = "Jill",
            Children = new List<string>
            {
                "Sam",
                "Mary"
            },
            Address = new Address
            {
                // Address changed
                Street = "64 Barnett Street",
                Country = "USA"
            }
        };
    }
}

^{snippet source | anchor}

And the test is re run it will fail with

Verification command has been copied to the clipboard.
Assert.Equal() Failure
                                  ↓ (pos 21)
Expected: ···\n  GivenNames: 'John',\n  FamilyName: 'Smith',\n  Spouse: 'Jill···
Actual:   ···\n  GivenNames: 'John James',\n  FamilyName: 'Smith',\n  Spouse:···
                                  ↑ (pos 21)

The clipboard will again contain the following:

cmd /c move /Y "C:\Code\Sample\Sample.Test.received.txt" "C:\Code\Sample\Sample.Test.verified.txt"

The Diff Tool is will display the diff:

The same approach can be used to verify the results and the change to Sample.Test.verified.txt is committed to source control along with the change to ClassBeingTested.

Received and Verified

All *.verified.* files should be committed to source control.
All *.received.* files should be excluded from source control.

Videos

Verify Xunit Intro

Extensions

Verify.AngleSharp.Diffing: Comparison of html files via AngleSharp.Diffing.
Verify.Aspose: Verification of documents (pdf, docx, xslx, and pptx) via Aspose.
Verify.Blazor: Verification of Blazor Component via bunit or via raw Blazor rendering.
Verify.EntityFramework: Verification of EntityFramework bits.
Verify.ICSharpCode.Decompiler: Comparison of assemblies and types via ICSharpCode.Decompiler.
Verify.ImageMagick: Verification and comparison of images via Magick.NET.
Verify.ImageSharp: Verification of images via ImageSharp.
Verify.NServiceBus: Verify NServiceBus Test Contexts.
Verify.Phash: Comparison of documents via Phash.
Verify.Selenium: Verification of Web UIs using Selenium.
Verify.SqlServer: Verification of SqlServer bits.
Verify.Uno: Verification to allow verification of Uno UIs.
Verify.Web: Verification of web bits.
Verify.WinForms: Verification of WinForms UIs.
Verify.Xaml: Verification of Xaml UIs.
Verify.Xamarin: Verification of Xamarin UIs.

Alternatives

Projects/tools that may be a better alternative to Verify

Security contact information

To report a security vulnerability, use the Tidelift security contact. Tidelift will coordinate the fix and disclosure.

Icon

Helmet designed by Leonidas Ikonomou from The Noun Project.

benmccallum / Verify

Verify

Contents

NuGet packages

Usage

Class being tested

xUnit

NUnit

MSTest

Initial Verification

Verified result

Subsequent Verification

The Diff Tool is will display the diff:

Received and Verified

Videos

Extensions

More Documentation

Alternatives

Security contact information

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