VB.NET ShortCircuit Example

ShortCircuitTests.vb

Imports System.Text
Imports Microsoft.VisualStudio.TestTools.UnitTesting
Imports System.Runtime.CompilerServices

Module StringExtensions

    <Extension()>
    Public Function IsLongerThan10Characters(ByVal value As String) As Boolean
        Return value IsNot Nothing AndAlso value.Length > 10
    End Function

End Module

<TestClass()>
Public Class GivenANullString

    Dim _result As Boolean

    <TestInitialize()>
    Public Sub Setup()
        Dim value As String = Nothing

        Me._result = value.IsLongerThan10Characters()
    End Sub

    <TestMethod()>
    Public Sub AndAlsoShouldShortCircuit()
        Assert.IsFalse(Me._result)
    End Sub

End Class

<TestClass()>
Public Class GivenAString

    Dim _result As Boolean

    <TestInitialize()>
    Public Sub Setup()
        Dim value As String = "Good Day Sir"

        Me._result = value.IsLongerThan10Characters()
    End Sub

    <TestMethod()>
    Public Sub AndAlsoShouldShortCircuit()
        Assert.IsTrue(Me._result)
    End Sub

End Class