1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/task4/solution11/test/org/apidesign/apifest08/test/Task2Test.java Sat Oct 11 23:38:46 2008 +0200
1.3 @@ -0,0 +1,140 @@
1.4 +package org.apidesign.apifest08.test;
1.5 +
1.6 +import java.util.ArrayList;
1.7 +import java.util.Collection;
1.8 +import junit.framework.TestCase;
1.9 +import org.apidesign.apifest08.currency.Convertor;
1.10 +import org.apidesign.apifest08.currency.CurrencyValue;
1.11 +import org.apidesign.apifest08.currency.ExchangeRateValue;
1.12 +
1.13 +/** There are many currencies around the world and many banks manipulate
1.14 + * with more than one or two at the same time. As banks are usually the
1.15 + * best paying clients, which is true even in case of your Convertor API,
1.16 + * it is reasonable to listen to their requests.
1.17 + * <p>
1.18 + * The quest for today is to enhance your existing convertor API to hold
1.19 + * information about many currencies and allow conversions between any of them.
1.20 + * Also, as conversion rates for diferent currencies usually arise from various
1.21 + * bank departments, there is another important need. There is a need to
1.22 + * compose two convertors into one by merging all the information about
1.23 + * currencies they know about.
1.24 + */
1.25 +public class Task2Test extends TestCase {
1.26 +
1.27 + public Task2Test(String testName) {
1.28 + super(testName);
1.29 + }
1.30 +
1.31 + @Override
1.32 + protected void setUp() throws Exception {
1.33 + }
1.34 +
1.35 + @Override
1.36 + protected void tearDown() throws Exception {
1.37 + }
1.38 +
1.39 + // As in Task1Test, keep in mind, that there are three parts
1.40 + // of the whole system:
1.41 + // 1. there is someone who knows the current exchange rate
1.42 + // 2. there is someone who wants to do the conversion
1.43 + // 3. there is the API between 1. and 2. which allows them to communicate
1.44 + //
1.45 + // Please backward compatibly enhance your existing API to support following
1.46 + // usecases:
1.47 + //
1.48 + /** Create convertor that understands two currencies, CZK and
1.49 + * SKK. Make 100 SKK == 75 CZK. This is method for the group of users that
1.50 + * knows the exchange rate, and needs to use the API to create objects
1.51 + * with the exchange rate. Anyone shall be ready to call this method without
1.52 + * any other method being called previously. The API itself shall know
1.53 + * nothing about any rates, before this method is called.
1.54 + */
1.55 + public static Convertor<Double, String> createTripleConvertor() {
1.56 + // Rates: 1USD = 15CZK
1.57 + // Rates: 1USD = 20SKK
1.58 + // Rates: 75CZK = 100SKK
1.59 + Collection<ExchangeRateValue<Double, String>> exchangeRates =
1.60 + new ArrayList<ExchangeRateValue<Double, String>>();
1.61 + exchangeRates.add(ExchangeRateValue.getExchangeRate(
1.62 + CurrencyValue.getCurrencyValue(1d, "USD"),
1.63 + CurrencyValue.getCurrencyValue(15d, "CZK")));
1.64 + exchangeRates.add(ExchangeRateValue.getExchangeRate(
1.65 + CurrencyValue.getCurrencyValue(1d, "USD"),
1.66 + CurrencyValue.getCurrencyValue(20d, "SKK")));
1.67 + exchangeRates.add(ExchangeRateValue.getExchangeRate(
1.68 + CurrencyValue.getCurrencyValue(75d, "CZK"),
1.69 + CurrencyValue.getCurrencyValue(100d, "SKK")));
1.70 + return Convertor.getConvertorDoubleString(exchangeRates);
1.71 + }
1.72 +
1.73 + /** Define convertor that understands three currencies. Use it.
1.74 + */
1.75 + public void testConvertorForUSDandCZKandSKK() throws Exception {
1.76 + Convertor<Double, String> c = createTripleConvertor();
1.77 +
1.78 + CurrencyValue<Double, String> result;
1.79 + // convert $5 to CZK using c:
1.80 + // assertEquals("Result is 75 CZK");
1.81 + result = c.convert("CZK", CurrencyValue.getCurrencyValue(5d, "USD"));
1.82 + assertEquals(CurrencyValue.getCurrencyValue(75d, "CZK"), result);
1.83 +
1.84 + // convert $5 to SKK using c:
1.85 + // assertEquals("Result is 100 SKK");
1.86 + result = c.convert("SKK", CurrencyValue.getCurrencyValue(5d, "USD"));
1.87 + assertEquals(CurrencyValue.getCurrencyValue(100d, "SKK"), result);
1.88 +
1.89 + // convert 200SKK to CZK using c:
1.90 + // assertEquals("Result is 150 CZK");
1.91 + result = c.convert("CZK", CurrencyValue.getCurrencyValue(200d, "SKK"));
1.92 + assertEquals(CurrencyValue.getCurrencyValue(150d, "CZK"), result);
1.93 +
1.94 + // convert 200SKK to USK using c:
1.95 + // assertEquals("Result is 10 USD");
1.96 + result = c.convert("USD", CurrencyValue.getCurrencyValue(200d, "SKK"));
1.97 + assertEquals(CurrencyValue.getCurrencyValue(10d, "USD"), result);
1.98 + }
1.99 +
1.100 + /** Merge all currency rates of convertor 1 with convertor 2.
1.101 + * Implement this using your API, preferably this method just delegates
1.102 + * into some API method which does the actual work, without requiring
1.103 + * API clients to code anything complex.
1.104 + */
1.105 + public static Convertor<Double, String> merge(Convertor<Double, String> one, Convertor<Double, String> two) {
1.106 + return Convertor.mergeConvertorsDoubleString(one, two);
1.107 + }
1.108 +
1.109 + /** Join the convertors from previous task, Task1Test and show that it
1.110 + * can be used to do reasonable conversions.
1.111 + */
1.112 + public void testConvertorComposition() throws Exception {
1.113 + Convertor<Double, String> c = merge(
1.114 + Task1Test.createCZKtoUSD(),
1.115 + Task1Test.createSKKtoCZK());
1.116 +
1.117 + CurrencyValue<Double, String> result;
1.118 + // convert $5 to CZK using c:
1.119 + // assertEquals("Result is 85 CZK");
1.120 + result = c.convert("CZK", CurrencyValue.getCurrencyValue(5d, "USD"));
1.121 + assertEquals(CurrencyValue.getCurrencyValue(85d, "CZK"), result);
1.122 +
1.123 + // convert $8 to CZK using c:
1.124 + // assertEquals("Result is 136 CZK");
1.125 + result = c.convert("CZK", CurrencyValue.getCurrencyValue(8d, "USD"));
1.126 + assertEquals(CurrencyValue.getCurrencyValue(136d, "CZK"), result);
1.127 +
1.128 + // convert 1003CZK to USD using c:
1.129 + // assertEquals("Result is 59 USD");
1.130 + result = c.convert("USD", CurrencyValue.getCurrencyValue(1003d, "CZK"));
1.131 + assertEquals(CurrencyValue.getCurrencyValue(59d, "USD"), result);
1.132 +
1.133 + // convert 16CZK using c:
1.134 + // assertEquals("Result is 20 SKK");
1.135 + result = c.convert("SKK", CurrencyValue.getCurrencyValue(16d, "CZK"));
1.136 + assertEquals(CurrencyValue.getCurrencyValue(20d, "SKK"), result);
1.137 +
1.138 + // convert 500SKK to CZK using c:
1.139 + // assertEquals("Result is 400 CZK");
1.140 + result = c.convert("CZK", CurrencyValue.getCurrencyValue(500d, "SKK"));
1.141 + assertEquals(CurrencyValue.getCurrencyValue(400d, "CZK"), result);
1.142 + }
1.143 +}