1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/task2/solution13/test/org/apidesign/apifest08/test/Task2Test.java Tue Oct 07 01:18:23 2008 +0200
1.3 @@ -0,0 +1,136 @@
1.4 +package org.apidesign.apifest08.test;
1.5 +
1.6 +import java.math.BigDecimal;
1.7 +import junit.framework.TestCase;
1.8 +import org.apidesign.apifest08.currency.Convertor;
1.9 +import org.apidesign.apifest08.currency.ConvertorCurrency;
1.10 +import org.apidesign.apifest08.currency.ExchangeRateProvider;
1.11 +
1.12 +/** There are many currencies around the world and many banks manipulate
1.13 + * with more than one or two at the same time. As banks are usually the
1.14 + * best paying clients, which is true even in case of your Convertor API,
1.15 + * it is reasonable to listen to their requests.
1.16 + * <p>
1.17 + * The quest for today is to enhance your existing convertor API to hold
1.18 + * information about many currencies and allow conversions between any of them.
1.19 + * Also, as conversion rates for diferent currencies usually arise from various
1.20 + * bank departments, there is another important need. There is a need to
1.21 + * compose two convertors into one by merging all the information about
1.22 + * currencies they know about.
1.23 + */
1.24 +public class Task2Test extends TestCase {
1.25 + private static ConvertorCurrency currencyCZK = ConvertorCurrency.getInstance("CZK");
1.26 + private static ConvertorCurrency currencySKK = ConvertorCurrency.getInstance("SKK");
1.27 + private static ConvertorCurrency currencyUSD = ConvertorCurrency.getInstance("USD");
1.28 +
1.29 + public Task2Test(String testName) {
1.30 + super(testName);
1.31 + }
1.32 +
1.33 + @Override
1.34 + protected void setUp() throws Exception {
1.35 +
1.36 + }
1.37 +
1.38 + @Override
1.39 + protected void tearDown() throws Exception {
1.40 + }
1.41 +
1.42 + public static Convertor createUsdToSkkConvertor() {
1.43 + ConvertorCurrency fromCurrency = currencyUSD;
1.44 + ConvertorCurrency toCurrency = currencyUSD;
1.45 + ExchangeRateProvider exchangeRateProvider = new ExchangeRateProvider(new BigDecimal(1), fromCurrency, new BigDecimal(20), toCurrency);
1.46 +
1.47 + return Convertor.createConvertor(exchangeRateProvider);
1.48 +
1.49 + }
1.50 +
1.51 + // As in Task1Test, keep in mind, that there are three parts
1.52 + // of the whole system:
1.53 + // 1. there is someone who knows the current exchange rate
1.54 + // 2. there is someone who wants to do the conversion
1.55 + // 3. there is the API between 1. and 2. which allows them to communicate
1.56 + //
1.57 + // Please backward compatibly enhance your existing API to support following
1.58 + // usecases:
1.59 + //
1.60 +
1.61 + /** Create convertor that understands two currencies, CZK and
1.62 + * SKK. Make 100 SKK == 75 CZK. This is method for the group of users that
1.63 + * knows the exchange rate, and needs to use the API to create objects
1.64 + * with the exchange rate. Anyone shall be ready to call this method without
1.65 + * any other method being called previously. The API itself shall know
1.66 + * nothing about any rates, before this method is called.
1.67 + */
1.68 + public static Convertor createTripleConvertor() {
1.69 + ExchangeRateProvider exRateProvider = ExchangeRateProvider.createExchangeRateProvider();
1.70 +
1.71 + // Rates: 1USD = 15CZK
1.72 + exRateProvider.addFixedCurencyRate(currencyUSD, new BigDecimal(1),currencyCZK, new BigDecimal(15));
1.73 +
1.74 + // Rates: 1USD = 20SKK
1.75 + exRateProvider.addFixedCurencyRate(currencyUSD, new BigDecimal(1), currencySKK, new BigDecimal(20));
1.76 +
1.77 + // Rates: 75CZK = 100SKK
1.78 + exRateProvider.addFixedCurencyRate(currencyCZK, new BigDecimal(75), currencySKK, new BigDecimal(100));
1.79 +
1.80 + Convertor c = Convertor.createConvertor(exRateProvider);
1.81 +
1.82 + return c;
1.83 + }
1.84 +
1.85 + /** Define convertor that understands three currencies. Use it.
1.86 + */
1.87 + public void testConvertorForUSDandCZKandSKK() throws Exception {
1.88 + Convertor c = createTripleConvertor();
1.89 +
1.90 + // convert $5 to CZK using c:
1.91 + assertEquals("Result is 75 CZK",new BigDecimal("75.00"),c.convertWithReversibleRates(currencyUSD, currencyCZK, new BigDecimal(5)).getConverted());
1.92 +
1.93 +
1.94 + // convert $5 to SKK using c:
1.95 + assertEquals("Result is 100 SKK",new BigDecimal("100.00"),c.convertWithReversibleRates(currencyUSD, currencySKK, new BigDecimal(5)).getConverted());
1.96 +
1.97 + // convert 200SKK to CZK using c:
1.98 + assertEquals("Result is 150 CZK",new BigDecimal("150.00"),c.convertWithReversibleRates(currencySKK, currencyCZK, new BigDecimal(200)).getConverted());
1.99 +
1.100 + // convert 200SKK to USK using c:
1.101 + // assertEquals("Result is 10 USD");
1.102 + }
1.103 +
1.104 + /** Merge all currency rates of convertor 1 with convertor 2.
1.105 + * Implement this using your API, preferably this method just delegates
1.106 + * into some API method which does the actual work, without requiring
1.107 + * API clients to code anything complex.
1.108 + */
1.109 + public static Convertor merge(Convertor one, Convertor two) {
1.110 + return Convertor.createConvertorAsMerge(new Convertor[]{one, two});
1.111 + }
1.112 +
1.113 + /** Join the convertors from previous task, Task1Test and show that it
1.114 + * can be used to do reasonable conversions.
1.115 + */
1.116 + public void testConvertorComposition() throws Exception {
1.117 + Convertor c = merge(
1.118 + Task1Test.createCZKtoUSD(),
1.119 + Task1Test.createSKKtoCZK()
1.120 + );
1.121 +
1.122 + // convert $5 to CZK using c:
1.123 + assertEquals("Result is 85 CZK",new BigDecimal("85.00"),c.convertWithReversibleRates(currencyUSD, currencyCZK, new BigDecimal(5)).getConverted());
1.124 +
1.125 + // convert $8 to CZK using c:
1.126 + // assertEquals("Result is 136 CZK");
1.127 + assertEquals("Result is 136 CZK",new BigDecimal("136.00"),c.convertWithReversibleRates(currencyUSD, currencyCZK, new BigDecimal(8)).getConverted());
1.128 +
1.129 + // convert 1003CZK to USD using c:
1.130 + assertEquals("Result is 59 USD",new BigDecimal("59.00"),c.convertWithReversibleRates(currencyCZK, currencyUSD, new BigDecimal(1003)).getConverted());
1.131 +
1.132 + // convert 16CZK using c:
1.133 + assertEquals("Result is 20 SKK",new BigDecimal("20.00"),c.convertWithReversibleRates(currencyCZK, currencySKK, new BigDecimal(16)).getConverted());
1.134 +
1.135 + // convert 500SKK to CZK using c:
1.136 + assertEquals("Result is 400 CZK",new BigDecimal("400.00"),c.convertWithReversibleRates(currencySKK, currencyCZK, new BigDecimal(500)).getConverted());
1.137 +
1.138 + }
1.139 +}