Reputation: 31

How to check equality of items of two list using Assert in Nunit

I'm fairly new to unit testing. The following code is just for reference. I want to check empId of list one is same as the emp id of list 2 or not.

public class EmpInfo
{    
    public EmpInfo( string lastName,string firstName, string empId)
    {
        EAlphabeticLastName = lastName;
        EFirstName = firstName;
        EmpId = empId;
    }
}

[Test]
[Category("Explicit")]
public void testEmp() 
{
    public List<EmpInfo> List1e = new List<EmpInfo>(){        
            new EmpInfo("dx","Tex","25")  
    };

    public List<EmpInfo> List2e = new List<EmpInfo>(){          
            new EmpInfo("dx","Tex","25")  
    };
    Assert.AreEqual(List1e.empId,List2e.empId);
}

What is the correct way to check equality of list items in Nunit (C#) ?

Upvotes: 1

Answers (4)

Nguyễn Văn Phong

Reputation: 14198

There are numerous ways to achieve it

Use https://fluentassertions.com/objectgraphs/ (The easiest and fastest way)

    List1e.Should().BeEquivalentTo(List2e);

Move all the individual comparisons to the .Equals method (Or implement IEqualityComparer)
Build a helper method that iterates through public properties by reflection and assert each property

      public static void PropertyValuesAreEquals(object actual, object expected)   {
        PropertyInfo[] properties = expected.GetType().GetProperties();
        foreach (PropertyInfo property in properties)
        {
            object expectedValue = property.GetValue(expected, null);
            object actualValue = property.GetValue(actual, null);
          if (!Equals(expectedValue, actualValue))
                Assert.Fail("Property {0}.{1} does not match. Expected: {2} but was: {3}", property.DeclaringType.Name, property.Name, expectedValue, actualValue);
          //……………………………….
        }

Use JSON to compare the object’s data

    public static void AreEqualByJson(object expected, object actual)
    {
       var serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
       var expectedJson = serializer.Serialize(expected);
       var actualJson = serializer.Serialize(actual);
       Assert.AreEqual(expectedJson, actualJson);
    }

Use Property Constraints (NUnit 2.4.2)

Upvotes: 1

Charlie

Reputation: 13681

Alternatives to checking that the list contains only items with the same ID:

Implement equality for the EmpInfo class, as suggested by User965207, either by overriding Equals or implementing the IEquatable interface. NUnit will use either one if present. If you don't have control over the code of the system under test, this is of course not available to you.
Use a Select statement to create a new list for comparison, as suggested by Sean. You actually only need to do this for the actual value being tested. Your expected value can just be a list or array of empids in the first place. This approach only requires changing the test code.
Use NUnit's List class to do essentially the same as option 2 for you...

Assert.That(List.Map(List1e).Property("empid"), Is.EqualTo(new [] {"empid1", "empid2" /etc/}));

Since you have not provided a full implementation of EmpInfo, I made the assumption that empid is a property. If it's a field, this won't work.