public void WriteTest()
{
StringBuilder buffer = new StringBuilder();
var mock = new Mock <TextWriter>();
mock.Setup(
(m) => m.WriteLine(It.IsAny <string>()))
.Callback <string>(
(s) =>
{
buffer.Append(s);
});
var invoiceWriter = new InvoiceWriter(mock.Object);
var invoice = new Invoice();
invoice.SetOwnerTelNumber("090-1234-0001");
invoice.SetBasicCharge(1100);
invoice.AddCallCharge(230);
invoiceWriter.Write(invoice);
string expected =
"1 090-1234-0001" +
"5 1100" +
"7 230" +
"9 ====================";
Assert.AreEqual(expected, buffer.ToString());
}