Unit testing of WF code activity - unit-testing

Question

I have created coded activity and now I want to unit test it, but I do not know how.
Any example will be appreciated.
My simple example is below.
public sealed class ParameterActivity : CodeActivity
{
public InArgument<int> Argument1 { get; set; }
public InArgument<int> Argument2 { get; set; }
public OutArgument<int> Result { get; set; }
protected override void Execute(CodeActivityContext context)
{
var a = context.GetValue(Argument1);
var b = context.GetValue(Argument2);
context.SetValue(Result, a + b);
}
}

Answer 1

First of all, in case your activity returns a single value, just inherit from CodeActivity<TResult> and easily override Execute() with TResult as return type. Moreover, you've already available an OutArgument<TResult> Result.
public sealed class ParameterActivity : CodeActivity<int>
{
public InArgument<int> Argument1 { get; set; }
public InArgument<int> Argument2 { get; set; }
protected override int Execute(CodeActivityContext context)
{
var a = Argument1.Get(context);
var b = Argument2.Get(context);
return a + b;
}
}
That being said, WorkflowInvoker is the way to go to unit test almost all your activities. Taking above custom code activity as example:
[TestFixture]
public sealed class ParameterActivityTests
{
[Test]
public void ParameterActivity_Test()
{
var activity = new ParameterActivity();
var input1 = new Dictionary<string, object>
{
{ "Argument1", 10 },
{ "Argument2", 5 }
};
var input2 = new Dictionary<string, object>
{
{ "Argument1", -13 },
{ "Argument2", 3 }
};
var output1 = WorkflowInvoker.Invoke<int>(activity, input1);
var output2 = WorkflowInvoker.Invoke<int>(activity, input2);
Assert.That(output1, Is.EqualTo(15));
Assert.That(output2, Is.EqualTo(-10));
}
}
Rather than WorkflowInvoker you can also use WorkflowApplication but for unit testing that doesn't seem at all necessary when you just want to quickly invoke short-lived workflows for them to do "their thing" and return. Unless you want to test more elaborate stuff like asynchronous workflows and/or bookmarks.
You'll also want to check Microsoft.Activities.UnitTesting.