Polishing.

Remove unused imports. Use more explicit lambda parameter naming.

Also, adopt tests to changed Spring Data Relational SQL generation.

Original pull request: #690.
See #689

Author: mp911de

src/main/java/org/springframework/data/r2dbc/core/DefaultDatabaseClient.java

@@ -1486,7 +1486,7 @@ private <R> FetchSpec<R> exchangeInsert(BiFunction<Row, RowMetadata, R> mappingF
 
 		String sql = getRequiredSql(operation);
 		Function<Connection, Statement> insertFunction = wrapPreparedOperation(sql, operation)
-				.andThen(statement -> statement.returnGeneratedValues());
+				.andThen(Statement::returnGeneratedValues);
 		Function<Connection, Flux<Result>> resultFunction = toFunction(sql, StatementFilterFunctions.empty(),
 				insertFunction);
 

src/main/java/org/springframework/data/r2dbc/core/R2dbcEntityTemplate.java

@@ -571,9 +571,9 @@ <T> Mono<T> doInsert(T entity, SqlIdentifier tableName) {
 
 		RelationalPersistentEntity<T> persistentEntity = getRequiredEntity(entity);
 
-		return maybeCallBeforeConvert(entity, tableName).flatMap(it -> {
+		return maybeCallBeforeConvert(entity, tableName).flatMap(onBeforeConvert -> {
 
-			T initializedEntity = setVersionIfNecessary(persistentEntity, it);
+			T initializedEntity = setVersionIfNecessary(persistentEntity, onBeforeConvert);
 
 			OutboundRow outboundRow = dataAccessStrategy.getOutboundRow(initializedEntity);
 
@@ -676,25 +676,25 @@ private <T> Mono<T> doUpdate(T entity, SqlIdentifier tableName) {
 
 		RelationalPersistentEntity<T> persistentEntity = getRequiredEntity(entity);
 
-		return maybeCallBeforeConvert(entity, tableName).flatMap(it -> {
+		return maybeCallBeforeConvert(entity, tableName).flatMap(onBeforeConvert -> {
 
 			T entityToUse;
 			Criteria matchingVersionCriteria;
 
 			if (persistentEntity.hasVersionProperty()) {
 
-				matchingVersionCriteria = createMatchingVersionCriteria(it, persistentEntity);
-				entityToUse = incrementVersion(persistentEntity, it);
+				matchingVersionCriteria = createMatchingVersionCriteria(onBeforeConvert, persistentEntity);
+				entityToUse = incrementVersion(persistentEntity, onBeforeConvert);
 			} else {
 
-				entityToUse = it;
+				entityToUse = onBeforeConvert;
 				matchingVersionCriteria = null;
 			}
 
 			OutboundRow outboundRow = dataAccessStrategy.getOutboundRow(entityToUse);
 
 			return maybeCallBeforeSave(entityToUse, outboundRow, tableName) //
-					.flatMap(entityToSave -> {
+					.flatMap(onBeforeSave -> {
 
 						SqlIdentifier idColumn = persistentEntity.getRequiredIdProperty().getColumnName();
 						Parameter id = outboundRow.remove(idColumn);
@@ -704,7 +704,7 @@ private <T> Mono<T> doUpdate(T entity, SqlIdentifier tableName) {
 							criteria = criteria.and(matchingVersionCriteria);
 						}
 
-						return doUpdate(entityToSave, tableName, persistentEntity, criteria, outboundRow);
+						return doUpdate(onBeforeSave, tableName, persistentEntity, criteria, outboundRow);
 					});
 		});
 	}

src/test/java/org/springframework/data/r2dbc/core/DefaultDatabaseClientUnitTests.java

@@ -256,7 +256,7 @@ void insertShouldAcceptSettableValue() {
 	@Test // gh-390
 	void insertShouldWorkWithoutValues() {
 
-		Statement statement = mockStatementFor("INSERT INTO id_only VALUES ()");
+		Statement statement = mockStatementFor("INSERT INTO id_only VALUES (DEFAULT)");
 		DatabaseClient databaseClient = databaseClientBuilder.build();
 
 		databaseClient.insert().into("id_only") //

src/test/java/org/springframework/data/r2dbc/core/R2dbcEntityTemplateUnitTests.java

@@ -22,7 +22,6 @@
 import io.r2dbc.spi.test.MockResult;
 import io.r2dbc.spi.test.MockRow;
 import io.r2dbc.spi.test.MockRowMetadata;
-import lombok.ToString;
 import lombok.Value;
 import lombok.With;
 import reactor.core.publisher.Mono;