japod@6: package org.apidesign.apifest08.test;
japod@6: 
japod@6: import junit.framework.TestCase;
japod@6: import org.apidesign.apifest08.currency.Convertor;
japod@6: import org.apidesign.apifest08.currency.CurrencyValue;
japod@6: 
japod@6: /** Finish the Convertor API, and then write bodies of methods inside
japod@6:  * of this class to match the given tasks. To fullfil your task, use the
japod@6:  * API define in the <code>org.apidesign.apifest08.currency</code> package.
japod@6:  * Do not you reflection, or other hacks as your code
japod@6:  * shall run without any runtime permissions.
japod@6:  */
japod@6: public class Task1Test extends TestCase {
japod@6:     public Task1Test(String testName) {
japod@6:         super(testName);
japod@6:     }
japod@6: 
japod@6:     @Override
japod@6:     protected void setUp() throws Exception {
japod@6:     }
japod@6: 
japod@6:     @Override
japod@6:     protected void tearDown() throws Exception {
japod@6:     }
japod@6: 
japod@19:     //
japod@19:     // Imagine that there are three parts of the whole system:
japod@19:     // 1. there is someone who knows the current exchange rate
japod@19:     // 2. there is someone who wants to do the conversion
japod@19:     // 3. there is the API between 1. and 2. which allows them to communicate
japod@19:     // Please design such API
japod@19:     //
japod@19: 
japod@6:     /** Create convertor that understands two currencies, CZK and
japod@19:      *  USD. Make 1 USD == 17 CZK. This is a method provided for #1 group -
japod@19:      *  e.g. those that know the exchange rate. They somehow need to create
japod@19:      *  the objects from the API and tell them the exchange rate. The API itself
japod@19:      *  knows nothing about any rates, before the createCZKtoUSD method is called.
japod@6:      *
japod@6:      * Creation of the convertor shall not require subclassing of any class
japod@6:      * or interface on the client side.
japod@6:      *
japod@6:      * @return prepared convertor ready for converting USD to CZK and CZK to USD
japod@6:      */
japod@53:     public static Convertor<Double, String> createCZKtoUSD() {
japod@53:         return Convertor.getConvertorDoubleString(
japod@53:                 CurrencyValue.getCurrencyValue(1d, "USD"),
japod@53:                 CurrencyValue.getCurrencyValue(17d, "CZK")
japod@6:         );
japod@6:     }
japod@6: 
japod@6:     /** Create convertor that understands two currencies, CZK and
japod@19:      *  SKK. Make 100 SKK == 80 CZK. Again this is method for the #1 group -
japod@19:      *  it knows the exchange rate, and needs to use the API to create objects
japod@19:      *  with the exchange rate. Anyone shall be ready to call this method without
japod@19:      *  any other method being called previously. The API itself shall know
japod@19:      *  nothing about any rates, before this method is called.
japod@6:      *
japod@6:      * Creation of the convertor shall not require subclassing of any class
japod@6:      * or interface on the client side.
japod@6:      * 
japod@6:      * @return prepared convertor ready for converting SKK to CZK and CZK to SKK
japod@6:      */
japod@53:     public static Convertor<Double, String> createSKKtoCZK() {
japod@53:         return Convertor.getConvertorDoubleString(
japod@53:                 CurrencyValue.getCurrencyValue(100d, "SKK"),
japod@53:                 CurrencyValue.getCurrencyValue(80d, "CZK")
japod@6:         );
japod@6:     }
japod@19: 
japod@19:     //
japod@19:     // now the methods for group #2 follow:
japod@19:     // this group knows nothing about exchange rates, but knows how to use
japod@19:     // the API to do conversions. It somehow (by calling one of the factory
japod@19:     // methods) gets objects from the API and uses them to do the conversions.
japod@19:     //
japod@6:     
japod@6:     /** Use the convertor from <code>createCZKtoUSD</code> method and do few conversions
japod@6:      * with it.
japod@6:      */
japod@6:     public void testCurrencyCZKUSD() throws Exception {
japod@53:         Convertor<Double, String> c = createCZKtoUSD();
japod@6:         
japod@53:         CurrencyValue<Double, String> result;
japod@6:         
japod@6:         // convert $5 to CZK using c:
japod@6:         // assertEquals("Result is 85 CZK");
japod@53:         result = c.convert("CZK", CurrencyValue.getCurrencyValue(5d, "USD"));
japod@53:         assertEquals(CurrencyValue.getCurrencyValue(85d, "CZK"), result);
japod@6: 
japod@6:         // convert $8 to CZK
japod@6:         // assertEquals("Result is 136 CZK");
japod@53:         result = c.convert("CZK", CurrencyValue.getCurrencyValue(8d, "USD"));
japod@53:         assertEquals(CurrencyValue.getCurrencyValue(136d, "CZK"), result);
japod@6: 
japod@6:         // convert 1003CZK to USD
japod@6:         // assertEquals("Result is 59 USD");
japod@53:         result = c.convert("USD", CurrencyValue.getCurrencyValue(1003d, "CZK"));
japod@53:         assertEquals(CurrencyValue.getCurrencyValue(59d, "USD"), result);
japod@6:     }
japod@6: 
japod@6:     /** Use the convertor from <code>createSKKtoCZK</code> method and do few conversions
japod@6:      * with it.
japod@6:      */
japod@6:     public void testCurrencySKKCZK() throws Exception {
japod@53:         Convertor<Double, String> c = createSKKtoCZK();
japod@6:         
japod@53:         CurrencyValue<Double, String> result;
japod@6:         
japod@6:         // convert 16CZK using c:
japod@6:         // assertEquals("Result is 20 SKK");
japod@53:         result = c.convert("SKK", CurrencyValue.getCurrencyValue(16d, "CZK"));
japod@53:         assertEquals(CurrencyValue.getCurrencyValue(20d, "SKK"), result);
japod@6: 
japod@6:         // convert 500SKK to CZK
japod@6:         // assertEquals("Result is 400 CZK");
japod@53:         result = c.convert("CZK", CurrencyValue.getCurrencyValue(500d, "SKK"));
japod@53:         assertEquals(CurrencyValue.getCurrencyValue(400d, "CZK"), result);
japod@6:     }
japod@19: 
japod@19:     /** Verify that the CZK to USD convertor knows nothing about SKK.
japod@19:      */
japod@19:     public void testCannotConvertToSKKwithCZKUSDConvertor() throws Exception {
japod@53:         Convertor<Double, String> c = createCZKtoUSD();
japod@19:         try {
japod@19:             // convert $5 to SKK, the API shall say this is not possible
japod@53:             c.convert("SKK", CurrencyValue.getCurrencyValue(16d, "CZK"));
japod@53:             fail("Should not convert");
japod@19:         } catch (Exception e) {
japod@19:         }
japod@19:         try {
japod@19:             // convert 500 SKK to CZK, the API shall say this is not possible
japod@53:             c.convert("CZK", CurrencyValue.getCurrencyValue(500d, "SKK"));
japod@53:             fail("Should not convert");
japod@19:         } catch (Exception e) {
japod@19:         }
japod@19:         
japod@19:     }
japod@19: 
japod@19:     /** Verify that the CZK to SKK convertor knows nothing about USD.
japod@19:      */
japod@19:     public void testCannotConvertToUSDwithSKKCZKConvertor() throws Exception {
japod@53:         Convertor<Double, String> c = createSKKtoCZK();
japod@19:         try {
japod@19:             // convert $5 to SKK, the API shall say this is not possible
japod@53:             c.convert("SKK", CurrencyValue.getCurrencyValue(5d, "USD"));
japod@53:             fail("Should not convert");
japod@19:         } catch (Exception e) {
japod@19:         }
japod@19:         try {
japod@19:             // convert 500 CZK to USD, the API shall say this is not possible
japod@53:             c.convert("USD", CurrencyValue.getCurrencyValue(500d, "CZK"));
japod@53:             fail("Should not convert");
japod@19:         } catch (Exception e) {
japod@19:         }
japod@19:     }
japod@6: }