Enhance tests deleting errors in AbstractApplicationErrorDaoTest (#356)

* Update the tests for deleting resolved and unresolved errors
  so they work as long as the database timestamp precision is
  at least milliseconds (e.g., when using SQLite can only get to millis)
* Enhance those tests with additional assertions to verify only the expected
  ApplicationErrors were deleted

src/test/java/org/kiwiproject/dropwizard/error/dao/AbstractApplicationErrorDaoTest.java

@@ -15,6 +15,7 @@
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
+import org.kiwiproject.base.DefaultEnvironment;
 import org.kiwiproject.dropwizard.error.model.ApplicationError;
 import org.kiwiproject.dropwizard.error.model.ApplicationError.Resolved;
 import org.kiwiproject.dropwizard.error.test.junit.jupiter.ApplicationErrorExtension;
@@ -248,29 +249,47 @@ void shouldChangeOnlyUnresolvedErrors() {
     }
 
     @Test
-    void shouldDeleteAllResolvedErrors() {
-        insertApplicationError(randomResolvedApplicationError());
-        insertApplicationError(randomUnresolvedApplicationError());
+    void shouldDeleteResolvedErrors_BeforeReferenceDate() {
+        var resolvedId1 = insertApplicationError(randomResolvedApplicationError());
+        var unresolvedId1 = insertApplicationError(randomUnresolvedApplicationError());
+
+        // Ensure the next createdAt is AFTER previous ones as long as
+        // the database timestamp precision is at least milliseconds
+        sleep5ms();
 
         var timeInBetween = ZonedDateTime.now();
-        insertApplicationError(randomResolvedApplicationError());
+        var resolvedId2 = insertApplicationError(randomResolvedApplicationError());
 
         var count = errorDao.deleteResolvedErrorsBefore(timeInBetween);
 
         assertThat(count).isOne();
+        assertThat(errorDao.getById(resolvedId1)).isEmpty();
+        assertThat(errorDao.getById(unresolvedId1)).isPresent();
+        assertThat(errorDao.getById(resolvedId2)).isPresent();
     }
 
     @Test
-    void shouldDeleteUnresolvedErrors() {
-        insertApplicationError(randomResolvedApplicationError());
-        insertApplicationError(randomUnresolvedApplicationError());
+    void shouldDeleteUnresolvedErrors_BeforeReferenceDate() {
+        var resolvedId1 = insertApplicationError(randomResolvedApplicationError());
+        var unresolvedId1 = insertApplicationError(randomUnresolvedApplicationError());
+
+        // Ensure the createdAt is AFTER previous ones as long as
+        // the database timestamp precision is at least milliseconds
+        sleep5ms();
 
         var timeInBetween = ZonedDateTime.now();
-        insertApplicationError(randomResolvedApplicationError());
+        var unresolvedId2 = insertApplicationError(randomUnresolvedApplicationError());
 
         var count = errorDao.deleteUnresolvedErrorsBefore(timeInBetween);
 
         assertThat(count).isOne();
+        assertThat(errorDao.getById(resolvedId1)).isPresent();
+        assertThat(errorDao.getById(unresolvedId1)).isEmpty();
+        assertThat(errorDao.getById(unresolvedId2)).isPresent();
+    }
+
+    private static void sleep5ms() {
+        new DefaultEnvironment().sleepQuietly(5);
     }
 
     @Test