How to get NUnit to test all values in a list, rather than just the first failure

Question

Just some example code here, but I have lists of strings that I want to test my functions against. The part that I don't like is that NUnit stops in each test when the first Assert fails. I'd like to test each value and report each failure, rather than just the first one. I don't want to have to write a new [Test] function for each string though.

Is there a way to do this?

using NUnit.Framework;
using System.Collections.Generic;

namespace Examples
{
    [TestFixture]
    public class ExampleTests
    {
        private List<string> validStrings = new List<string> { "Valid1", "valid2", "valid3", "Valid4" };
        private List<string> invalidStrings = new List<string> { "Invalid1", "invalid2", "invalid3", "" };

        [Test]
        public void TestValidStrings()
        {
            foreach (var item in validStrings)
            {
                Assert.IsTrue(item.Contains("valid"), item);
            }
        }

        [Test]
        public void TestInvalidStrings()
        {
            foreach (var item in invalidStrings)
            {
                Assert.IsFalse(item.Contains("invalid"), item);
            }
        }
    }
}

Answer 1

Use the [TestCaseSource] attribute to specify values to pass into your (now parameterized) test method.

We use this a lot in Noda Time to test a lot of cases with different cultures and strings.

Here's your example, converted to use it:

using NUnit.Framework;
using System.Collections.Generic;

// Namespace removed for brevity    
[TestFixture]
public class ExampleTests
{
    private List<string> validStrings = new List<string> 
        { "Valid1", "valid2", "valid3", "Valid4" };
    private List<string> invalidStrings = new List<string> 
        { "Invalid1", "invalid2", "invalid3", "" };

    [Test]
    [TestCaseSource("validStrings")]
    public void TestValidStrings(string item)
    {
        Assert.IsTrue(item.Contains("valid"), item);
    }

    [Test]
    [TestCaseSource("invalidStrings")]
    public void TestInvalidStrings(string item)
    {
        Assert.IsFalse(item.Contains("invalid"), item);
    }
}

Note that another option is to use [TestCase] which means you don't need separate variables for your test data.