#30 - Address review feedback.

Author: mp911de

src/main/java/org/springframework/data/r2dbc/dialect/PostgresDialect.java

@@ -8,7 +8,6 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashSet;
-import java.util.List;
 import java.util.Set;
 import java.util.UUID;
 
@@ -24,7 +23,7 @@
 public class PostgresDialect implements Dialect {
 
 	private static final Set<Class<?>> SIMPLE_TYPES = new HashSet<>(
-			Arrays.asList(List.class, Collection.class, UUID.class, URL.class, URI.class, InetAddress.class));
+			Arrays.asList(UUID.class, URL.class, URI.class, InetAddress.class));
 
 	/**
 	 * Singleton instance.

src/test/java/org/springframework/data/r2dbc/dialect/PostgresDialectUnitTests.java

@@ -1,8 +1,10 @@
 package org.springframework.data.r2dbc.dialect;
 
 import static org.assertj.core.api.Assertions.*;
+import static org.assertj.core.api.SoftAssertions.*;
+
+import java.util.List;
 
-import org.assertj.core.api.SoftAssertions;
 import org.junit.Test;
 import org.springframework.data.mapping.model.SimpleTypeHolder;
 
@@ -30,7 +32,7 @@ public void shouldConsiderSimpleTypes() {
 
 		SimpleTypeHolder holder = PostgresDialect.INSTANCE.getSimpleTypeHolder();
 
-		SoftAssertions.assertSoftly(it -> {
+		assertSoftly(it -> {
 			it.assertThat(holder.isSimpleType(String.class)).isTrue();
 			it.assertThat(holder.isSimpleType(int.class)).isTrue();
 			it.assertThat(holder.isSimpleType(Integer.class)).isTrue();
@@ -50,9 +52,11 @@ public void shouldUseBoxedArrayTypesForPrimitiveTypes() {
 
 		ArrayColumns arrayColumns = PostgresDialect.INSTANCE.getArraySupport();
 
-		assertThat(arrayColumns.getArrayType(int.class)).isEqualTo(Integer.class);
-		assertThat(arrayColumns.getArrayType(double.class)).isEqualTo(Double.class);
-		assertThat(arrayColumns.getArrayType(String.class)).isEqualTo(String.class);
+		assertSoftly(it -> {
+			it.assertThat(arrayColumns.getArrayType(int.class)).isEqualTo(Integer.class);
+			it.assertThat(arrayColumns.getArrayType(double.class)).isEqualTo(Double.class);
+			it.assertThat(arrayColumns.getArrayType(String.class)).isEqualTo(String.class);
+		});
 	}
 
 	@Test // gh-30
@@ -62,4 +66,12 @@ public void shouldRejectNonSimpleArrayTypes() {
 
 		assertThatThrownBy(() -> arrayColumns.getArrayType(getClass())).isInstanceOf(IllegalArgumentException.class);
 	}
+
+	@Test // gh-30
+	public void shouldRejectNestedCollections() {
+
+		ArrayColumns arrayColumns = PostgresDialect.INSTANCE.getArraySupport();
+
+		assertThatThrownBy(() -> arrayColumns.getArrayType(List.class)).isInstanceOf(IllegalArgumentException.class);
+	}
 }