sales_tax_tests.rb

require 'test/unit'

class TestSalesTaxApp < Test::Unit::TestCase
  def setup
    # load the inputs
    require 'sales_tax.rb'
  end
  
  def test_rounding_off
    assert_equal(78.9, 78.876.round_to(1))
    assert_equal(78.88, 78.876.round_to(2))
    assert_equal(0.23, 0.233.round_to(2))
    assert_equal(0.11, 0.110.round_to(2))
    assert_equal(0.0, 0.01.round_to(1))
  end
  
  def test_exempted
    assert(Item.new(:item => 'pickaxe book').exempted?)
    assert(Item.new(:item => 'pickaxe BOOK').exempted?)
  end
  
  def test_imported
    assert(Item.new(:item => 'imported perfume').imported?)
    assert(Item.new(:item => 'IMPORTED perfume').imported?)
  end
  
  def test_tax_calculations
    i = Item.new(:item => 'imported book', :price => 100)
    assert_equal(5, i.sales_tax)
    i = Item.new(:item => 'fever pills', :price => 10)
    assert_equal(0, i.sales_tax)
    i = Item.new(:item => 'IMPORTED fever pills', :price => 10)
    assert_equal(0.5, i.sales_tax)
  end
  
  def test_price
    i = Item.new(:item => 'imported book', :price => 107.897628)
    assert_equal(113.29, i.price)
  end
  
  def test_bad_input
  end
  
  def test_0_values
    assert_raises(ArgumentError) {Item.new()}
    assert_nothing_raised {Item.new(:item => "")} # Replace it with something useful
  end
  
  def test_null_values
  end
  
end