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Data Driven Tests

Inject compile-time known data via [Arguments(...)] attributes. The attribute takes an array of arguments that must match the test method's parameter count and types. Multiple [Arguments] attributes repeat the test once per attribute:

using TUnit.Assertions;
using TUnit.Assertions.Extensions;
using TUnit.Core;

namespace MyTestProject;

public class MyTestClass
{
    [Test]
    [Arguments(1, 1, 2)]
    [Arguments(1, 2, 3)]
    [Arguments(2, 2, 4)]
    [Arguments(4, 3, 7)]
    [Arguments(5, 5, 10)]
    public async Task MyTest(int value1, int value2, int expectedResult)
    {
        var result = Add(value1, value2);

        await Assert.That(result).IsEqualTo(expectedResult);
    }

    private int Add(int x, int y)
    {
        return x + y;
    }
}

Test Case Metadata​

The [Arguments] attribute supports optional properties to customize individual test cases:

Custom Display Names​

Use the DisplayName property to provide a human-readable name for each test case:

[Test]
[Arguments(1, 1, 2, DisplayName = "One plus one equals two")]
[Arguments(0, 0, 0, DisplayName = "Zero plus zero equals zero")]
[Arguments(-1, 1, 0, DisplayName = "Negative and positive cancel out")]
public async Task Addition(int a, int b, int expected)
{
    await Assert.That(a + b).IsEqualTo(expected);
}

Display names support parameter substitution using $paramName or positional $arg1, $arg2 syntax:

[Test]
[Arguments(2, 3, 5, DisplayName = "Adding $a + $b = $expected")]
[Arguments(10, 5, 15, DisplayName = "$arg1 + $arg2 = $arg3")]
public async Task AdditionWithSubstitution(int a, int b, int expected)
{
    await Assert.That(a + b).IsEqualTo(expected);
}

Categories​

Apply categories to specific test cases for filtering:

[Test]
[Arguments(100, 50, Categories = new[] { "LargeNumbers", "Performance" })]
[Arguments(1, 1, Categories = new[] { "SmallNumbers", "Smoke" })]
public async Task CategorizedTests(int a, int b)
{
    await Assert.That(a + b).IsGreaterThan(0);
}

Skipping Test Cases​

Use the Skip property to skip specific test cases:

[Test]
[Arguments("Chrome", "120")]
[Arguments("Firefox", "121")]
[Arguments("Safari", "17", Skip = "Safari testing not available in CI")]
public async Task BrowserTest(string browser, string version)
{
    // Test implementation
}

Combining Properties​

All properties can be combined:

[Test]
[Arguments("admin", "secret123", DisplayName = "Admin login", Categories = new[] { "Auth", "Admin" })]
[Arguments("guest", "guest", DisplayName = "Guest login", Categories = new[] { "Auth" })]
[Arguments("", "", DisplayName = "Empty credentials", Skip = "Edge case not implemented")]
public async Task LoginTest(string username, string password)
{
    // Test implementation
}
tip

For dynamic test data or complex objects, use Method Data Sources with TestDataRow for the same metadata capabilities.