C# How to Unit Test a Method that has multiple Inputs and Outputs?

October 13, 2022

I’ve been tasked to implement unit tests for a lot of modules in a firm and the only Problem I’ve encountered so far is for Methods where they have about 20 Input Variables and 15 Output variables. How do I even check for so many possibilities?

>Solution :

Well, i guess then method looks something like this:

public Output Process(T1 input1, ..., T20 input20) { ... }

where Output would be

public class Output
{
    public OutputT1 Output1 { get; set; }
    ...
    public OutputT15 Output15 { get; set; }
}

So your test method could look like this:

[Fact]
public void TestProcessing()
{
    // Arrange
    var input1 = new T1(); // set some appropriate data
    ...
    var input20 = new T20(); // set some appropriate data

    // Also set expected values
    var actualOutput1 = new OutputT1();
    ...
    var actualOutput15 = new OutputT15();

    // Act
    var output = _sut.Process(input1, ..., input20);

    // Assert
    Assert.Equals(output.Output1, actualOutput1);
    ...
    Assert.Equals(output.Output15, actualOutput15);
}