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Test Parameters

TUnit allows you to pass custom key-value parameters to your tests at runtime using the --test-parameter command-line option. These parameters are accessible via TestContext.Parameters.

Passing Parameters​

Pass parameters when running your tests using the --test-parameter flag with KEY=VALUE syntax:

dotnet run --test-parameter environment=staging
dotnet run --test-parameter environment=staging --test-parameter api-url=https://api.example.com

You can pass multiple values for the same key:

dotnet run --test-parameter browser=chrome --test-parameter browser=firefox

Accessing Parameters in Tests​

Parameters are available as a static dictionary on TestContext:

public class MyTests
{
    [Test]
    public async Task ConnectsToCorrectEnvironment()
    {
        var environments = TestContext.Parameters["environment"];
        var environment = environments.First(); // "staging"

        // Use the parameter to configure your test
        var baseUrl = environment switch
        {
            "production" => "https://api.example.com",
            "staging" => "https://staging.api.example.com",
            _ => "http://localhost:5000"
        };

        // ...
    }
}

TestContext.Parameters is of type IReadOnlyDictionary<string, List<string>>. Each key maps to a list of values, since the same key can be specified multiple times on the command line.

Common Use Cases​

Environment-specific configuration​

[Before(Test)]
public void SetupEnvironment()
{
    if (TestContext.Parameters.TryGetValue("environment", out var values))
    {
        Environment.SetEnvironmentVariable("TEST_ENV", values.First());
    }
}

Conditional test logic​

[Test]
public async Task IntegrationTest()
{
    if (!TestContext.Parameters.ContainsKey("run-integration"))
    {
        Assert.Skip("Integration tests require --test-parameter run-integration=true");
    }

    // Run the integration test...
}

Passing secrets or connection strings​

[Test]
public async Task DatabaseTest()
{
    if (!TestContext.Parameters.TryGetValue("connection-string", out var connectionStrings))
    {
        Assert.Skip("Requires --test-parameter connection-string=...");
    }

    using var connection = new SqlConnection(connectionStrings.First());
    // ...
}
dotnet run --test-parameter "connection-string=Server=localhost;Database=TestDb;..."

Notes​

  • Parameters are available for the entire test session — they are not scoped to individual tests.
  • The parameter format must be KEY=VALUE. Values containing = characters are supported (only the first = is used as the delimiter).
  • Parameters are accessible from any test, hook, or data source via TestContext.Parameters.