DATAREDIS-973 - Polishing.

Use connection factory customizer for setting db index when creating new connection. This allows to grasp the tests setup more quickly and improves readability. Original Pull Request: spring-projects#451

Author: christophstrobl

src/test/java/org/springframework/data/redis/connection/lettuce/LettuceConnectionFactoryTests.java

@@ -37,7 +37,6 @@
 import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Test;
-
 import org.springframework.data.redis.ConnectionFactoryTracker;
 import org.springframework.data.redis.RedisConnectionFailureException;
 import org.springframework.data.redis.RedisSystemException;
@@ -140,11 +139,26 @@ public void testSelectDb() {
 // put an item in database 0
 connection.set("sometestkey", "sometestvalue");
 
-LettuceConnectionFactory sharingConnectionFactory = newConnectionFactory(cf -> {});
+LettuceConnectionFactory sharingConnectionFactory = newConnectionFactory(cf -> cf.setDatabase(1));
 runSelectDbTest(sharingConnectionFactory);
 
-LettuceConnectionFactory nonSharingConnectionFactory = newConnectionFactory(
-cf -> cf.setShareNativeConnection(false));
+LettuceConnectionFactory nonSharingConnectionFactory = newConnectionFactory(cf -> {
+cf.setDatabase(1);
+cf.setShareNativeConnection(false);
+});
+runSelectDbTest(nonSharingConnectionFactory);
+}
+
+@Test // DATAREDIS-973
+public void testSelectDbReactive() {
+
+LettuceConnectionFactory sharingConnectionFactory = newConnectionFactory(cf -> cf.setDatabase(1));
+runSelectDbReactiveTest(sharingConnectionFactory);
+
+LettuceConnectionFactory nonSharingConnectionFactory = newConnectionFactory(cf -> {
+cf.setDatabase(1);
+cf.setShareNativeConnection(false);
+});
 runSelectDbTest(nonSharingConnectionFactory);
 }
 
@@ -167,17 +181,6 @@ private void runSelectDbTest(LettuceConnectionFactory factory2) {
 }
 }
 
-@Test // DATAREDIS-973
-public void testSelectDbReactive() {
-
-LettuceConnectionFactory sharingConnectionFactory = newConnectionFactory(cf -> {});
-runSelectDbReactiveTest(sharingConnectionFactory);
-
-LettuceConnectionFactory nonSharingConnectionFactory = newConnectionFactory(
-cf -> cf.setShareNativeConnection(false));
-runSelectDbTest(nonSharingConnectionFactory);
-}
-
 private void runSelectDbReactiveTest(LettuceConnectionFactory factory2) {
 
 ConnectionFactoryTracker.add(factory2);
@@ -209,7 +212,6 @@ private static LettuceConnectionFactory newConnectionFactory(Consumer<LettuceCon
 SettingsUtils.getPort());
 connectionFactory.setClientResources(LettuceTestClientResources.getSharedClientResources());
 connectionFactory.setShutdownTimeout(0);
-connectionFactory.setDatabase(1);
 customizer.accept(connectionFactory);
 connectionFactory.afterPropertiesSet();