[TUnit] infrastructure fixtures appear in verified filenames / add VerifierSettings.IgnoreParameters<T>

[georg-jung]

Is the feature request related to a problem

Yes:

Background

I recently migrated a test suite from Verify.xUnit to Verify.TUnit. The migration surfaced two differences in snapshot filename generation that frictioned the migration path for me. This is about finding ways to improve the migration experience.

Context: how I understand xUnit and TUnit differ in fixture injection

In xUnit, infrastructure fixtures are injected via IClassFixture<T> / ICollectionFixture<T> - a mechanism that is completely separate from test method parameters. As a result, fixture types are invisible to Verify.xUnit's naming logic.

TUnit uses the same mechanisms for shared infrastructure fixtures (e.g. [ClassDataSource<T>(Shared = SharedType.PerTestSession)]) and test data shared across multiple test cases. Verify.TUnit therefore includes all constructor parameters in the parameters list alongside method parameters.

Current behaviour: constructor parameters (incl. infrastructure fixtures) appear in snapshot filenames

When a TUnit test class has a constructor parameter that carries a shared fixture - e.g., a test database - the fixture's parameter name appears in the generated snapshot filename:

MyTests.MyTest_testDatabaseFixture=MyNamespace.TestDatabaseFixture_days=7_flag=True.verified.txt

Currently this can be worked around at Verify callsite:

await Verify(result).IgnoreParameters("testDatabaseFixture");

I think this must be repeated on every Verify() call in every fixture-using class, since IgnoreParameters is not available on global VerifierSettings.

Describe the solution

Possible improvement: a global API such as VerifierSettings.IgnoreParameters<T>() (or VerifierSettings.IgnoreClassArguments()) that would provide an opt-out of fixture-type parameters across the board, without touching individual Verify() calls. Or, maybe it could make sense to provide exclusion based on SharedType.

Describe alternatives considered

• updating all Verify callsites
• renaming all verified files

Additional context

The MWE below uses file-based apps.

MWE: infrastructure fixture appears in snapshot filename

mwe1.cs

#:property TargetFramework=net10.0
#:property PublishAot=false
#:package TUnit@1.*
#:package Verify.TUnit@31.13.*

using System.Runtime.CompilerServices;

public static class ModuleInit
{
    [ModuleInitializer]
    public static void Init() => VerifierSettings.AutoVerify();
}

public class TestDatabaseFixture;

[ClassDataSource<TestDatabaseFixture>(Shared = SharedType.PerTestSession)]
public class MweTests(TestDatabaseFixture testDatabaseFixture)
{
    // Desired filename: MweTests.TestWithFixture_days=7_active=True.verified.txt
    // Actual filename:  MweTests.TestWithFixture_testDatabaseFixture=TestDatabaseFixture_days=7_active=True.verified.txt

    [Test]
    [Arguments(7, true)]
    [Arguments(14, false)]
    public Task TestWithFixture(int days, bool active)
        => Verify(new { days, active });

    [Test]
    [Arguments(7, true)]
    [Arguments(14, false)]
    public Task TestWithFixtureAndWorkaround(int days, bool active)
        => Verify(new { days, active }).IgnoreParameters(nameof(testDatabaseFixture));
}

The fixture's parameter name (testDatabaseFixture) and type appear in the filename. For a test migrated from xUnit (where fixtures were invisible to Verify), every .verified.txt file from such a class would need renaming, or every Verify() call would need .IgnoreParameters("testDatabaseFixture") added.

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Is there any existing recommended configuration that doesn't require changing all Verify-callsites?

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Thank you for creating Verify! I really enjoy using it in multiple projects 🚀♥️

[georg-jung]

Thanks for jumping on this so quickly! 🚀

(For github's cross referencing: see #1701 and #1702)

[SimonCropp]

no worries

that deployed. give nuget ~15min to refresh its cache