Code for immutable domain blog part 5

InvoiceSpec.scala

"draft invoice" should {
  val invoice: DraftInvoice = Invoice.loadFromHistory(Seq(InvoiceCreated(1)))

  "support adding invoice items" in {
    val updated = invoice.addItem("Food", "2.95") flatMap (_.addItem("Water", "1.95")) flatMap (_.removeItem(1))

    updated.changes must contain(InvoiceItemAdded(1, InvoiceItem(1, "Food", "2.95"), "2.95"))
    updated.changes must contain(InvoiceItemAdded(1, InvoiceItem(2, "Water", "1.95"), "4.90"))
    updated.changes must contain(InvoiceItemRemoved(1, InvoiceItem(1, "Food", "2.95"), "1.95"))
  }

  "not be ready to send" in {
    invoice.send.rejected must beEqualTo("recipient and items must be specified before sending")
  }
}