#140 - Accept simple mapping function for Row in DatabaseClient.

We now accept a Function<Row, T> in DatabaseClient's map(…) operator to simplify mapping by not requiring RowMetadata.

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

@@ -23,6 +23,7 @@ import reactor.core.publisher.Mono;
 import java.util.Map;
 import java.util.function.BiFunction;
 import java.util.function.Consumer;
+import java.util.function.Function;
 import java.util.function.Supplier;
 
 import org.reactivestreams.Publisher;
@@ -229,6 +230,15 @@ public interface DatabaseClient {
 		 */
 		<R> TypedExecuteSpec<R> as(Class<R> resultType);
 
+		/**
+		 * Configure a result mapping {@link java.util.function.Function function}.
+		 *
+		 * @param mappingFunction must not be {@literal null}.
+		 * @param <R> result type.
+		 * @return a {@link FetchSpec} for configuration what to fetch. Guaranteed to be not {@literal null}.
+		 */
+		<R> RowsFetchSpec<R> map(Function<Row, R> mappingFunction);
+
 		/**
 		 * Configure a result mapping {@link java.util.function.BiFunction function}.
 		 *
@@ -265,6 +275,15 @@ public interface DatabaseClient {
 		 */
 		<R> TypedExecuteSpec<R> as(Class<R> resultType);
 
+		/**
+		 * Configure a result mapping {@link java.util.function.Function function}.
+		 *
+		 * @param mappingFunction must not be {@literal null}.
+		 * @param <R> result type.
+		 * @return a {@link FetchSpec} for configuration what to fetch. Guaranteed to be not {@literal null}.
+		 */
+		<R> RowsFetchSpec<R> map(Function<Row, R> mappingFunction);
+
 		/**
 		 * Configure a result mapping {@link java.util.function.BiFunction function}.
 		 *
@@ -393,6 +412,15 @@ public interface DatabaseClient {
 		 */
 		<R> TypedSelectSpec<R> as(Class<R> resultType);
 
+		/**
+		 * Configure a result mapping {@link java.util.function.Function function}.
+		 *
+		 * @param mappingFunction must not be {@literal null}.
+		 * @param <R> result type.
+		 * @return a {@link FetchSpec} for configuration what to fetch. Guaranteed to be not {@literal null}.
+		 */
+		<R> RowsFetchSpec<R> map(Function<Row, R> mappingFunction);
+
 		/**
 		 * Configure a result mapping {@link java.util.function.BiFunction function}.
 		 *
@@ -422,6 +450,15 @@ public interface DatabaseClient {
 		 */
 		<R> RowsFetchSpec<R> as(Class<R> resultType);
 
+		/**
+		 * Configure a result mapping {@link java.util.function.Function function}.
+		 *
+		 * @param mappingFunction must not be {@literal null}.
+		 * @param <R> result type.
+		 * @return a {@link FetchSpec} for configuration what to fetch. Guaranteed to be not {@literal null}.
+		 */
+		<R> RowsFetchSpec<R> map(Function<Row, R> mappingFunction);
+
 		/**
 		 * Configure a result mapping {@link java.util.function.BiFunction function}.
 		 *
@@ -556,6 +593,15 @@ public interface DatabaseClient {
 	 */
 	interface InsertSpec<T> {
 
+		/**
+		 * Configure a result mapping {@link java.util.function.Function function}.
+		 *
+		 * @param mappingFunction must not be {@literal null}.
+		 * @param <R> result type.
+		 * @return a {@link FetchSpec} for configuration what to fetch. Guaranteed to be not {@literal null}.
+		 */
+		<R> RowsFetchSpec<R> map(Function<Row, R> mappingFunction);
+
 		/**
 		 * Configure a result mapping {@link java.util.function.BiFunction function}.
 		 *

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

@@ -486,6 +486,14 @@ class DefaultDatabaseClient implements DatabaseClient, ConnectionAccessor {
 			return createTypedExecuteSpec(this.byIndex, this.byName, this.sqlSupplier, resultType);
 		}
 
+		@Override
+		public <R> FetchSpec<R> map(Function<Row, R> mappingFunction) {
+
+			Assert.notNull(mappingFunction, "Mapping function must not be null!");
+
+			return exchange(this.sqlSupplier, (row, rowMetadata) -> mappingFunction.apply(row));
+		}
+
 		@Override
 		public <R> FetchSpec<R> map(BiFunction<Row, RowMetadata, R> mappingFunction) {
 
@@ -571,6 +579,14 @@ class DefaultDatabaseClient implements DatabaseClient, ConnectionAccessor {
 			return createTypedExecuteSpec(this.byIndex, this.byName, this.sqlSupplier, resultType);
 		}
 
+		@Override
+		public <R> FetchSpec<R> map(Function<Row, R> mappingFunction) {
+
+			Assert.notNull(mappingFunction, "Mapping function must not be null!");
+
+			return exchange(this.sqlSupplier, (row, rowMetadata) -> mappingFunction.apply(row));
+		}
+
 		@Override
 		public <R> FetchSpec<R> map(BiFunction<Row, RowMetadata, R> mappingFunction) {
 
@@ -727,6 +743,14 @@ class DefaultDatabaseClient implements DatabaseClient, ConnectionAccessor {
 					resultType, dataAccessStrategy.getRowMapper(resultType));
 		}
 
+		@Override
+		public <R> FetchSpec<R> map(Function<Row, R> mappingFunction) {
+
+			Assert.notNull(mappingFunction, "Mapping function must not be null!");
+
+			return exchange((row, rowMetadata) -> mappingFunction.apply(row));
+		}
+
 		@Override
 		public <R> FetchSpec<R> map(BiFunction<Row, RowMetadata, R> mappingFunction) {
 
@@ -816,6 +840,14 @@ class DefaultDatabaseClient implements DatabaseClient, ConnectionAccessor {
 			return exchange(dataAccessStrategy.getRowMapper(resultType));
 		}
 
+		@Override
+		public <R> FetchSpec<R> map(Function<Row, R> mappingFunction) {
+
+			Assert.notNull(mappingFunction, "Mapping function must not be null!");
+
+			return exchange((row, rowMetadata) -> mappingFunction.apply(row));
+		}
+
 		@Override
 		public <R> FetchSpec<R> map(BiFunction<Row, RowMetadata, R> mappingFunction) {
 
@@ -935,6 +967,14 @@ class DefaultDatabaseClient implements DatabaseClient, ConnectionAccessor {
 			return new DefaultGenericInsertSpec<>(this.table, byName, this.mappingFunction);
 		}
 
+		@Override
+		public <R> FetchSpec<R> map(Function<Row, R> mappingFunction) {
+
+			Assert.notNull(mappingFunction, "Mapping function must not be null!");
+
+			return exchange((row, rowMetadata) -> mappingFunction.apply(row));
+		}
+
 		@Override
 		public <R> FetchSpec<R> map(BiFunction<Row, RowMetadata, R> mappingFunction) {
 
@@ -1017,6 +1057,14 @@ class DefaultDatabaseClient implements DatabaseClient, ConnectionAccessor {
 			return new DefaultTypedInsertSpec<>(this.typeToInsert, this.table, objectToInsert, this.mappingFunction);
 		}
 
+		@Override
+		public <MR> FetchSpec<MR> map(Function<Row, MR> mappingFunction) {
+
+			Assert.notNull(mappingFunction, "Mapping function must not be null!");
+
+			return exchange((row, rowMetadata) -> mappingFunction.apply(row));
+		}
+
 		@Override
 		public <MR> FetchSpec<MR> map(BiFunction<Row, RowMetadata, MR> mappingFunction) {
 

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

@@ -332,7 +332,7 @@ public abstract class AbstractDatabaseClientIntegrationTests extends R2dbcIntegr
 		databaseClient.select().from("legoset") //
 				.project("id", "name", "manual") //
 				.orderBy(Sort.by("id")) //
-				.map((r, md) -> r.get("id", Integer.class)) //
+				.map((r) -> r.get("id", Integer.class)) //
 				.all() //
 				.as(StepVerifier::create) //
 				.expectNext(42055) //
@@ -374,7 +374,7 @@ public abstract class AbstractDatabaseClientIntegrationTests extends R2dbcIntegr
 				.project("id", "name", "manual") //
 				.orderBy(Sort.by("id")) //
 				.matching(where("id").greaterThanOrEquals(42055).and("id").lessThanOrEquals(42055))
-				.map((r, md) -> r.get("id", Integer.class)) //
+				.map((r) -> r.get("id", Integer.class)) //
 				.all() //
 				.as(StepVerifier::create) //
 				.expectNext(42055) //