Extend unit tests for ExchangeRateService

Extend the unit tests with more granular checks.

pricenode/src/test/java/bisq/price/TestBase.java

@@ -0,0 +1,30 @@
+/*
+ * This file is part of Bisq.
+ *
+ * Bisq is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Bisq is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Bisq. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package bisq.price;
+
+import org.apache.commons.lang3.RandomStringUtils;
+
+/**
+ * Provide utility methods for other tests
+ */
+public abstract class TestBase {
+
+    protected static String getRandomAlphaNumericString(int length) {
+        return RandomStringUtils.random(length, true, true);
+    }
+}

pricenode/src/test/java/bisq/price/spot/ExchangeRateServiceTest.java

@@ -17,46 +17,120 @@
 
 package bisq.price.spot;
 
+import bisq.price.TestBase;
+
 import java.time.Duration;
 
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
-import org.junit.Test;
 
-public class ExchangeRateServiceTest {
+import org.slf4j.LoggerFactory;
+
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.Logger;
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.core.read.ListAppender;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+
+public class ExchangeRateServiceTest extends TestBase {
+
+    /**
+     * Logback version of the Slfj logger used by {@link ExchangeRateService}. This
+     * allows us to test if specific messages were logged <br/><br/>
+     *
+     * See https://stackoverflow.com/a/52229629
+     */
+    private static Logger exchangeRateServiceLogger;
+    private static final String LIST_APPENDER_NAME = "testListAppender";
+
+    @BeforeAll
+    static void setup () {
+        // Get the logger object for logs in ExchangeRateService
+        exchangeRateServiceLogger = (Logger) LoggerFactory.getLogger(ExchangeRateService.class);
+
+        // Initiate and append a ListAppender, which allows us to programmatically inspect log messages
+        ListAppender<ILoggingEvent> listAppender = new ListAppender<>();
+        listAppender.setName(LIST_APPENDER_NAME);
+        listAppender.start();
+        exchangeRateServiceLogger.addAppender(listAppender);
+    }
 
     @Test
     public void getAllMarketPrices_withNoExchangeRates_logs_Exception() {
-        ExchangeRateProvider dummyProvider = new ExchangeRateProvider("Dummy", "YUM", Duration.ofDays(1)) {
+        int numberOfCurrencyPairsOnExchange = 0;
+        ExchangeRateProvider dummyProvider = buildDummyExchangeRateProvider(numberOfCurrencyPairsOnExchange);
+        ExchangeRateService service = new ExchangeRateService(Collections.singletonList(dummyProvider));
 
-            @Override
-            public boolean isRunning() {
-                return true;
-            }
+        Map<String, Object> retrievedData = service.getAllMarketPrices();
 
-            @Override
-            protected Set<ExchangeRate> doGet() {
-                return Collections.emptySet();
-            }
-        };
+        doSanityChecksForRetrievedData(retrievedData, dummyProvider.getPrefix(), numberOfCurrencyPairsOnExchange);
 
-        dummyProvider.start();
-        dummyProvider.stop();
+        // No exchange rates provided by this exchange, two things should happen
+        // A) the timestamp should be set to 0
+        // B) an error should be logged
 
-        List<ExchangeRateProvider> providerList = new ArrayList<>(Collections.singleton(dummyProvider));
+        // A) Check that timestamp was set to 0
+        // This allows Bisq clients to eventually disregard data from this provider
+        assertEquals(0L, retrievedData.get(dummyProvider.getPrefix() + "Ts"));
 
-        ExchangeRateService service = new ExchangeRateService(providerList);
-
-        service.getAllMarketPrices();
+        // B) Check that an error is logged
+        // Log msg has the format: java.lang.IllegalStateException: No exchange rate data found for ExchangeName-JzfP1
+        List<ILoggingEvent> logsList = ((ListAppender) exchangeRateServiceLogger.getAppender(LIST_APPENDER_NAME)).list;
+        assertEquals(Level.ERROR, logsList.get(0).getLevel());
+        assertTrue(logsList.get(0).getMessage().endsWith("No exchange rate data found for " + dummyProvider.getName()));
     }
 
     @Test
     public void getAllMarketPrices_withSingleExchangeRate() {
-        ExchangeRateProvider dummyProvider = new ExchangeRateProvider("Dummy", "YUM", Duration.ofDays(1)) {
+        int numberOfCurrencyPairsOnExchange = 1;
+        ExchangeRateProvider dummyProvider = buildDummyExchangeRateProvider(numberOfCurrencyPairsOnExchange);
+        ExchangeRateService service = new ExchangeRateService(Collections.singletonList(dummyProvider));
+
+        Map<String, Object> retrievedData = service.getAllMarketPrices();
+
+        doSanityChecksForRetrievedData(retrievedData, dummyProvider.getPrefix(), numberOfCurrencyPairsOnExchange);
+
+        // One rate was provided by this exchange, so the timestamp should not be 0
+        assertNotEquals(0L, retrievedData.get(dummyProvider.getPrefix() + "Ts"));
+    }
+
+    /**
+     * Performs generic sanity checks on the response format and contents
+     *
+     * @param retrievedData Response data retrieved from the {@link ExchangeRateService}
+     * @param providerPrefix {@link ExchangeRateProvider#getPrefix()}
+     * @param numberOfCurrencyPairsOnExchange Number of currency pairs this exchange was initiated with
+     */
+    private void doSanityChecksForRetrievedData(Map<String, Object> retrievedData, String providerPrefix, int numberOfCurrencyPairsOnExchange) {
+        // Check that 3 entries were present in the service response:
+        // timestamp + count + price data (stored as a list under the key "data")
+        assertEquals(3, retrievedData.size());
+        assertNotNull(retrievedData.get(providerPrefix + "Ts"));
+        assertNotNull(retrievedData.get(providerPrefix + "Count"));
+        assertNotNull(retrievedData.get("data"));
+
+        // Check that the amount of provided exchange rates matches expected value
+        List<String> retrievedMarketPricesData = (List<String>) retrievedData.get("data");
+        assertEquals(numberOfCurrencyPairsOnExchange, retrievedMarketPricesData.size());
+    }
+
+    private ExchangeRateProvider buildDummyExchangeRateProvider(int numberOfRatesAvailable) {
+        ExchangeRateProvider dummyProvider = new ExchangeRateProvider(
+                "ExchangeName-" + getRandomAlphaNumericString(5),
+                "EXCH-" + getRandomAlphaNumericString(3),
+                Duration.ofDays(1)) {
 
             @Override
             public boolean isRunning() {
@@ -66,18 +140,24 @@ public class ExchangeRateServiceTest {
             @Override
             protected Set<ExchangeRate> doGet() {
                 HashSet<ExchangeRate> exchangeRates = new HashSet<>();
-                exchangeRates.add(new ExchangeRate("DUM", 0, 0L, "Dummy"));
+
+                // Simulate the required amount of rates
+                for (int i = 0; i < numberOfRatesAvailable; i++) {
+                    exchangeRates.add(new ExchangeRate(
+                            "DUM-" + getRandomAlphaNumericString(3), // random symbol, avoid duplicates
+                            0,
+                            System.currentTimeMillis(),
+                            getName())); // ExchangeRateProvider name
+                }
+
                 return exchangeRates;
             }
         };
 
+        // Initialize provider
         dummyProvider.start();
         dummyProvider.stop();
 
-        List<ExchangeRateProvider> providerList = new ArrayList<>(Collections.singleton(dummyProvider));
-
-        ExchangeRateService service = new ExchangeRateService(providerList);
-
-        service.getAllMarketPrices();
+        return dummyProvider;
     }
 }