jaroslav@32: package org.apidesign.apifest08.test;
jaroslav@32: 
jaroslav@32: import junit.framework.TestCase;
jaroslav@32: import org.apidesign.apifest08.currency.Convertor;
jaroslav@32: 
jaroslav@32: /** There are many currencies around the world and many banks manipulate
jaroslav@32:  * with more than one or two at the same time. As banks are usually the
jaroslav@32:  * best paying clients, which is true even in case of your Convertor API,
jaroslav@32:  * it is reasonable to listen to their requests.
jaroslav@32:  * <p>
jaroslav@32:  * The quest for today is to enhance your existing convertor API to hold
jaroslav@32:  * information about many currencies and allow conversions between any of them.
jaroslav@32:  * Also, as conversion rates for diferent currencies usually arise from various
jaroslav@32:  * bank departments, there is another important need. There is a need to
jaroslav@32:  * compose two convertors into one by merging all the information about
jaroslav@32:  * currencies they know about.
jaroslav@32:  */
jaroslav@32: public class Task2Test extends TestCase {
jaroslav@32:     public Task2Test(String testName) {
jaroslav@32:         super(testName);
jaroslav@32:     }
jaroslav@32: 
jaroslav@32:     @Override
jaroslav@32:     protected void setUp() throws Exception {
jaroslav@32:     }
jaroslav@32: 
jaroslav@32:     @Override
jaroslav@32:     protected void tearDown() throws Exception {
jaroslav@32:     }
jaroslav@32: 
jaroslav@32:     // As in Task1Test, keep in mind, that there are three parts
jaroslav@32:     // of the whole system:
jaroslav@32:     // 1. there is someone who knows the current exchange rate
jaroslav@32:     // 2. there is someone who wants to do the conversion
jaroslav@32:     // 3. there is the API between 1. and 2. which allows them to communicate
jaroslav@32:     // 
jaroslav@32:     // Please backward compatibly enhance your existing API to support following
jaroslav@32:     // usecases:
jaroslav@32:     //
jaroslav@32:     
jaroslav@32:     /** Create convertor that understands two currencies, CZK and
jaroslav@32:      *  SKK. Make 100 SKK == 75 CZK. This is method for the group of users that
jaroslav@32:      *  knows the exchange rate, and needs to use the API to create objects
jaroslav@32:      *  with the exchange rate. Anyone shall be ready to call this method without
jaroslav@32:      *  any other method being called previously. The API itself shall know
jaroslav@32:      *  nothing about any rates, before this method is called.
jaroslav@32:      */
jaroslav@32:     public static Convertor createTripleConvertor() {
jaroslav@32:         // Rates: 1USD = 15CZK
jaroslav@32:         // Rates: 1USD = 20SKK
jaroslav@32:         // Rates: 75CZK = 100SKK
jaroslav@32:         return null;
jaroslav@32:     }
jaroslav@32: 
jaroslav@32:     /** Define convertor that understands three currencies. Use it.
jaroslav@32:      */
jaroslav@32:     public void testConvertorForUSDandCZKandSKK() throws Exception {
jaroslav@32:         Convertor c = createTripleConvertor();
jaroslav@32: 
jaroslav@32:         // convert $5 to CZK using c:
jaroslav@32:         // assertEquals("Result is 75 CZK");
jaroslav@32: 
jaroslav@32:         // convert $5 to SKK using c:
jaroslav@32:         // assertEquals("Result is 100 SKK");
jaroslav@32: 
jaroslav@32:         // convert 200SKK to CZK using c:
jaroslav@32:         // assertEquals("Result is 150 CZK");
jaroslav@32: 
jaroslav@32:         // convert 200SKK to USK using c:
jaroslav@32:         // assertEquals("Result is 10 USD");
jaroslav@32:     }
jaroslav@32: 
jaroslav@32:     /** Merge all currency rates of convertor 1 with convertor 2.
jaroslav@32:      * Implement this using your API, preferably this method just delegates
jaroslav@32:      * into some API method which does the actual work, without requiring
jaroslav@32:      * API clients to code anything complex.
jaroslav@32:      */
jaroslav@32:     public static Convertor merge(Convertor one, Convertor two) {
jaroslav@32:         return null;
jaroslav@32:     }
jaroslav@32: 
jaroslav@32:     /** Join the convertors from previous task, Task1Test and show that it
jaroslav@32:      * can be used to do reasonable conversions.
jaroslav@32:      */
jaroslav@32:     public void testConvertorComposition() throws Exception {
jaroslav@32:         Convertor c = merge(
jaroslav@32:             Task1Test.createCZKtoUSD(),
jaroslav@32:             Task1Test.createSKKtoCZK()
jaroslav@32:         );
jaroslav@32: 
jaroslav@32:         // convert $5 to CZK using c:
jaroslav@32:         // assertEquals("Result is 85 CZK");
jaroslav@32: 
jaroslav@32:         // convert $8 to CZK using c:
jaroslav@32:         // assertEquals("Result is 136 CZK");
jaroslav@32: 
jaroslav@32:         // convert 1003CZK to USD using c:
jaroslav@32:         // assertEquals("Result is 59 USD");
jaroslav@32: 
jaroslav@32:         // convert 16CZK using c:
jaroslav@32:         // assertEquals("Result is 20 SKK");
jaroslav@32: 
jaroslav@32:         // convert 500SKK to CZK using c:
jaroslav@32:         // assertEquals("Result is 400 CZK");
jaroslav@32: 
jaroslav@32:     }
jaroslav@32: }