Using the Specification Design Pattern

Imports NUnit.Framework

<TestFixture()> _
Public Class GenericTests
    <Test()> _
    Public Sub TestDrum()
        Dim drum As New Drum("Acid", 500, New ContainerSpecification(ContainerFeature.Armored))
        Assert.AreEqual("Acid", drum.Chemical)
        Assert.AreEqual(500, drum.Size)

        Dim container As New Container(10000, ContainerFeature.Armored)
        Assert.IsTrue(drum.RequiredContainer.IsSatisfiedBy(container))
    End Sub

    <Test()> _
    Public Sub TestContainer()
        Dim container As New Container(10000, ContainerFeature.Armored)
        Assert.AreEqual(10000, container.capacity)
        Assert.AreEqual(ContainerFeature.Armored, container.Features)
    End Sub

    <Test()> _
    Public Sub TestAddDrumsToContainer()
        Dim container As New Container(10000, ContainerFeature.Armored)

        Dim acidDrum As New Drum("Acid", 2000, New ContainerSpecification(ContainerFeature.Armored))
        container.AddDrum(acidDrum)

        Dim tntDrum As New Drum("TNT", 3000, New ContainerSpecification(ContainerFeature.Armored))
        container.AddDrum(tntDrum)

        Assert.AreEqual(2, container.Drums.Count)
        Assert.AreEqual(5000, container.RemainingSpace)

    End Sub

    <Test()> _
    Public Sub CanAccommodate()
        Dim container As New Container(10000, ContainerFeature.Armored)

        Dim uraniumDrum As New Drum("Uranium", 11000, New ContainerSpecification(ContainerFeature.Armored))
        Assert.IsFalse(container.canAccommodate(uraniumDrum))

        Dim tntDrum As New Drum("TNT", 9000, New ContainerSpecification(ContainerFeature.Ventilated))
        Assert.IsFalse(container.canAccommodate(tntDrum))

        Dim sulpherDrum As New Drum("Sulpher", 10000, New ContainerSpecification(ContainerFeature.Armored))
        Assert.IsTrue(container.canAccommodate(sulpherDrum))
    End Sub

    <Test()> _
    Public Sub IsSafelyPacked()
        Dim container As New Container(10000, ContainerFeature.Armored)

        Dim uraniumDrum As New Drum("Uranium", 5000, New ContainerSpecification(ContainerFeature.Armored))
        container.AddDrum(uraniumDrum)

        Dim sulpherDrum As New Drum("Sulpher", 2000, New ContainerSpecification(ContainerFeature.Armored))
        container.AddDrum(sulpherDrum)

        Assert.IsTrue(container.isSafelyPacked)

        Dim tntDrum As New Drum("TNT", 3000, New ContainerSpecification(ContainerFeature.Ventilated))
        container.AddDrum(tntDrum)

        Assert.IsFalse(container.isSafelyPacked)
    End Sub

    <Test()> _
    Public Sub CompoundSpecification()
        ' Create Containers
        Dim armoredContainer As New Container(10000, ContainerFeature.Armored)
        Dim ventilatedContainer As New Container(10000, ContainerFeature.Ventilated)
        Dim armoredAndVentilatedContainer As New Container(10000, ContainerFeature.Armored Or ContainerFeature.Ventilated)

        ' Create Specifications
        Dim armoredSpec As New ContainerSpecification(ContainerFeature.Armored)
        Dim ventilatedSpec As New ContainerSpecification(ContainerFeature.Ventilated)
        Dim either As ContainerSpecification = armoredSpec Or ventilatedSpec
        Dim both As ContainerSpecification = armoredSpec And ventilatedSpec

        ' Create Drums, using Specifications to define acceptable containers
        Dim uraniumDrum As New Drum("Uranium", 5000, either)
        Dim tntDrum As New Drum("TNT", 5000, both)

        ' Test Containers against the acceptable definitions for each Drum
        ' uranium requires Either
        Assert.IsTrue(uraniumDrum.RequiredContainer.IsSatisfiedBy(armoredContainer))
        Assert.IsTrue(uraniumDrum.RequiredContainer.IsSatisfiedBy(ventilatedContainer))

        ' Test Containers against the acceptable definitions for each Drum
        ' tnt requires both
        Assert.IsTrue(tntDrum.RequiredContainer.IsSatisfiedBy(armoredAndVentilatedContainer))
        Assert.IsFalse(tntDrum.RequiredContainer.IsSatisfiedBy(armoredContainer))
        Assert.IsFalse(tntDrum.RequiredContainer.IsSatisfiedBy(ventilatedContainer))

    End Sub

End Class