[rrd4j] Make tests more deterministic by performing cleanup before and after each test (#21322)

Signed-off-by: Jimmy Tanagra <jcode@tanagra.id.au>

Author: jimtng

bundles/org.openhab.persistence.rrd4j/src/test/java/org/openhab/persistence/rrd4j/internal/RRD4jPersistenceServiceTest.java

@@ -14,9 +14,12 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.junit.jupiter.api.Assertions.fail;
 import static org.mockito.Mockito.when;
 
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.time.ZoneId;
 import java.time.ZonedDateTime;
 import java.util.Map;
@@ -124,17 +127,25 @@ private void configureSwitchItem(String suffix) throws Exception {
         when(itemRegistry.getItem("TestSwitch" + suffix)).thenReturn(switchItem);
     }
 
+    private void deleteDatabaseFile(String itemName) throws Exception {
+        Path dbFile = RRD4jPersistenceService.getDatabasePath(itemName);
+        Files.deleteIfExists(dbFile);
+    }
+
     @AfterEach
     void tearDown() throws Exception {
         if (service != null) {
             service.deactivate();
         }
+        deleteDatabaseFile(numberItem.getName());
+        deleteDatabaseFile(switchItem.getName());
     }
 
     @ParameterizedTest
     @ValueSource(booleans = { true, false })
     void storeAndRetrieveNumberValue(boolean reloadAfterStore) throws Exception {
         configureNumberItem(reloadAfterStore ? "_PERSISTED" : "_MEMORY");
+        deleteDatabaseFile(numberItem.getName());
 
         // Store a value
         service.store(numberItem);
@@ -168,6 +179,7 @@ void storeAndRetrieveNumberValue(boolean reloadAfterStore) throws Exception {
     @ValueSource(booleans = { true, false })
     void storeAndRetrieveSwitchValue(boolean reloadAfterStore) throws Exception {
         configureSwitchItem(reloadAfterStore ? "_PERSISTED" : "_MEMORY");
+        deleteDatabaseFile(switchItem.getName());
 
         // Store a value
         service.store(switchItem);
@@ -206,6 +218,7 @@ void storeAndRetrieveSwitchValue(boolean reloadAfterStore) throws Exception {
     @ValueSource(booleans = { true, false })
     void queryWithTimeRange(boolean reloadAfterStore) throws Exception {
         configureNumberItem(reloadAfterStore ? "_PERSISTED" : "_MEMORY");
+        deleteDatabaseFile(numberItem.getName());
 
         // Store a value
         service.store(numberItem);
@@ -229,7 +242,7 @@ void queryWithTimeRange(boolean reloadAfterStore) throws Exception {
         assertNotNull(results);
 
         // Verify we got at least one result
-        assertNotNull(results.iterator().hasNext());
+        assertTrue(results.iterator().hasNext());
     }
 
     @Test
@@ -259,6 +272,7 @@ void storeAndRetrieveWithInvalidDBConfig(boolean reloadAfterStore) throws Except
         service = new RRD4jPersistenceService(itemRegistry, Map.of("something.invalid", "invalid/path/to/db"));
 
         configureNumberItem(reloadAfterStore ? "_PERSISTED" : "_MEMORY");
+        deleteDatabaseFile(numberItem.getName());
 
         // Store a value
         service.store(numberItem);