Refactor: flushIfLiveRefurbishIsNotSupported method

bosk-mongo/src/test/java/io/vena/bosk/drivers/mongo/SchemaEvolutionTest.java

@@ -9,6 +9,7 @@
 import io.vena.bosk.drivers.mongo.MongoDriverSettings.ManifestMode;
 import io.vena.bosk.drivers.state.TestEntity;
 import io.vena.bosk.junit.ParametersByName;
+import java.io.IOException;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Stream;
 import org.junit.jupiter.api.AfterEach;
@@ -123,27 +124,7 @@ void pairwise_writeCompatible() throws Exception {
 		LOGGER.debug("Refurbish toBosk ({})", toBosk.name());
 		((MongoDriver<?>)toBosk.driver()).refurbish();
 
-		if (fromHelper.driverSettings.preferredDatabaseFormat() == SEQUOIA
-			&& toHelper.driverSettings.preferredDatabaseFormat() != SEQUOIA) {
-			// When switching format classes, the old format's state documents
-			// disappear.
-			// Sequoia, being a fundamentally single-document format that does not
-			// use transactions, is not able to handle the time window between
-			// when that document disappears and when the corresponding change
-			// event arrives. We could add complexity to Sequoia to cope with
-			// this situation, but the point of Sequoia is its simplicity.
-			//
-			// Instead, we have a documented limitation that refurbishing from
-			// Sequoia to another format has a risk that updates occurring during
-			// a certain window could be ignored, and recommend that refurbish
-			// operation occur during a period of quiescence.
-			//
-			// Performing a flush causes Sequoia to "notice" its document is gone
-			// and correctly reinitialize itself.
-
-			LOGGER.debug("Flush so fromBosk notices the refurbish ({})", fromBosk.name());
-			fromBosk.driver().flush();
-		}
+		flushIfLiveRefurbishIsNotSupported(fromBosk, fromHelper, toHelper);
 
 		LOGGER.debug("Set distinctive string using fromBosk ({})", fromBosk.name());
 		fromBosk.driver().submitReplacement(fromRefs.string(), "Distinctive String");
@@ -163,6 +144,40 @@ void pairwise_writeCompatible() throws Exception {
 //		System.out.println("Status: " + ((MongoDriver<?>)toBosk.driver()).readStatus());
 	}
 
+	/**
+	 * @param boskForUpdate      {@link Bosk} that is about to submit an update
+	 * @param helperForUpdate    {@link Helper} for the bosk that is about to submit an update
+	 * @param helperForRefurbish {@link Helper} for the bosk that performed the {@link MongoDriver#flush()} operation
+	 */
+	private static void flushIfLiveRefurbishIsNotSupported(
+		Bosk<TestEntity> boskForUpdate,
+		Helper helperForUpdate,
+		Helper helperForRefurbish
+	) throws IOException, InterruptedException {
+		if (helperForUpdate.driverSettings.preferredDatabaseFormat() == SEQUOIA
+			&& helperForRefurbish.driverSettings.preferredDatabaseFormat() != SEQUOIA) {
+			// When switching format classes, the old format's state documents
+			// disappear.
+			//
+			// Sequoia, being a fundamentally single-document format that does not
+			// use transactions, is not able to handle the time window between
+			// when that document disappears and when the corresponding change
+			// event arrives. We could add complexity to Sequoia to cope with
+			// this situation, but the point of Sequoia is its simplicity.
+			//
+			// Instead, we have a documented limitation that refurbishing from
+			// Sequoia to another format has a risk that updates occurring during
+			// a certain window could be ignored, and recommend that refurbish
+			// operation occur during a period of quiescence.
+			//
+			// Performing a flush causes Sequoia to "notice" its document is gone
+			// and correctly reinitialize itself.
+
+			LOGGER.debug("Flush so boskForUpdate notices the refurbish ({})", boskForUpdate.name());
+			boskForUpdate.driver().flush();
+		}
+	}
+
 	private static Bosk<TestEntity> newBosk(Helper helper) {
 		return new Bosk<TestEntity>("bosk" + boskCounter.incrementAndGet(), TestEntity.class, helper::initialRoot, helper.driverFactory);
 	}