diff -r 000000000000 -r a7e6f84fb078 task2/solution13/test/org/apidesign/apifest08/test/Task2Test.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/task2/solution13/test/org/apidesign/apifest08/test/Task2Test.java Tue Oct 07 01:18:23 2008 +0200 @@ -0,0 +1,136 @@ +package org.apidesign.apifest08.test; + +import java.math.BigDecimal; +import junit.framework.TestCase; +import org.apidesign.apifest08.currency.Convertor; +import org.apidesign.apifest08.currency.ConvertorCurrency; +import org.apidesign.apifest08.currency.ExchangeRateProvider; + +/** There are many currencies around the world and many banks manipulate + * with more than one or two at the same time. As banks are usually the + * best paying clients, which is true even in case of your Convertor API, + * it is reasonable to listen to their requests. + *

+ * The quest for today is to enhance your existing convertor API to hold + * information about many currencies and allow conversions between any of them. + * Also, as conversion rates for diferent currencies usually arise from various + * bank departments, there is another important need. There is a need to + * compose two convertors into one by merging all the information about + * currencies they know about. + */ +public class Task2Test extends TestCase { + private static ConvertorCurrency currencyCZK = ConvertorCurrency.getInstance("CZK"); + private static ConvertorCurrency currencySKK = ConvertorCurrency.getInstance("SKK"); + private static ConvertorCurrency currencyUSD = ConvertorCurrency.getInstance("USD"); + + public Task2Test(String testName) { + super(testName); + } + + @Override + protected void setUp() throws Exception { + + } + + @Override + protected void tearDown() throws Exception { + } + + public static Convertor createUsdToSkkConvertor() { + ConvertorCurrency fromCurrency = currencyUSD; + ConvertorCurrency toCurrency = currencyUSD; + ExchangeRateProvider exchangeRateProvider = new ExchangeRateProvider(new BigDecimal(1), fromCurrency, new BigDecimal(20), toCurrency); + + return Convertor.createConvertor(exchangeRateProvider); + + } + + // As in Task1Test, keep in mind, that there are three parts + // of the whole system: + // 1. there is someone who knows the current exchange rate + // 2. there is someone who wants to do the conversion + // 3. there is the API between 1. and 2. which allows them to communicate + // + // Please backward compatibly enhance your existing API to support following + // usecases: + // + + /** Create convertor that understands two currencies, CZK and + * SKK. Make 100 SKK == 75 CZK. This is method for the group of users that + * knows the exchange rate, and needs to use the API to create objects + * with the exchange rate. Anyone shall be ready to call this method without + * any other method being called previously. The API itself shall know + * nothing about any rates, before this method is called. + */ + public static Convertor createTripleConvertor() { + ExchangeRateProvider exRateProvider = ExchangeRateProvider.createExchangeRateProvider(); + + // Rates: 1USD = 15CZK + exRateProvider.addFixedCurencyRate(currencyUSD, new BigDecimal(1),currencyCZK, new BigDecimal(15)); + + // Rates: 1USD = 20SKK + exRateProvider.addFixedCurencyRate(currencyUSD, new BigDecimal(1), currencySKK, new BigDecimal(20)); + + // Rates: 75CZK = 100SKK + exRateProvider.addFixedCurencyRate(currencyCZK, new BigDecimal(75), currencySKK, new BigDecimal(100)); + + Convertor c = Convertor.createConvertor(exRateProvider); + + return c; + } + + /** Define convertor that understands three currencies. Use it. + */ + public void testConvertorForUSDandCZKandSKK() throws Exception { + Convertor c = createTripleConvertor(); + + // convert $5 to CZK using c: + assertEquals("Result is 75 CZK",new BigDecimal("75.00"),c.convertWithReversibleRates(currencyUSD, currencyCZK, new BigDecimal(5)).getConverted()); + + + // convert $5 to SKK using c: + assertEquals("Result is 100 SKK",new BigDecimal("100.00"),c.convertWithReversibleRates(currencyUSD, currencySKK, new BigDecimal(5)).getConverted()); + + // convert 200SKK to CZK using c: + assertEquals("Result is 150 CZK",new BigDecimal("150.00"),c.convertWithReversibleRates(currencySKK, currencyCZK, new BigDecimal(200)).getConverted()); + + // convert 200SKK to USK using c: + // assertEquals("Result is 10 USD"); + } + + /** Merge all currency rates of convertor 1 with convertor 2. + * Implement this using your API, preferably this method just delegates + * into some API method which does the actual work, without requiring + * API clients to code anything complex. + */ + public static Convertor merge(Convertor one, Convertor two) { + return Convertor.createConvertorAsMerge(new Convertor[]{one, two}); + } + + /** Join the convertors from previous task, Task1Test and show that it + * can be used to do reasonable conversions. + */ + public void testConvertorComposition() throws Exception { + Convertor c = merge( + Task1Test.createCZKtoUSD(), + Task1Test.createSKKtoCZK() + ); + + // convert $5 to CZK using c: + assertEquals("Result is 85 CZK",new BigDecimal("85.00"),c.convertWithReversibleRates(currencyUSD, currencyCZK, new BigDecimal(5)).getConverted()); + + // convert $8 to CZK using c: + // assertEquals("Result is 136 CZK"); + assertEquals("Result is 136 CZK",new BigDecimal("136.00"),c.convertWithReversibleRates(currencyUSD, currencyCZK, new BigDecimal(8)).getConverted()); + + // convert 1003CZK to USD using c: + assertEquals("Result is 59 USD",new BigDecimal("59.00"),c.convertWithReversibleRates(currencyCZK, currencyUSD, new BigDecimal(1003)).getConverted()); + + // convert 16CZK using c: + assertEquals("Result is 20 SKK",new BigDecimal("20.00"),c.convertWithReversibleRates(currencyCZK, currencySKK, new BigDecimal(16)).getConverted()); + + // convert 500SKK to CZK using c: + assertEquals("Result is 400 CZK",new BigDecimal("400.00"),c.convertWithReversibleRates(currencySKK, currencyCZK, new BigDecimal(500)).getConverted()); + + } +}