Make the cidr<->IPNetwork mapping the default (npgsql#5950)

Closes npgsql#5891

Author: roji

src/Npgsql/Internal/Converters/Networking/NpgsqlCidrConverter.cs

@@ -3,6 +3,7 @@
 // ReSharper disable once CheckNamespace
 namespace Npgsql.Internal.Converters;
 
+#pragma warning disable CS0618 // NpgsqlCidr is obsolete
 sealed class NpgsqlCidrConverter : PgBufferedConverter<NpgsqlCidr>
 {
     public override bool CanConvert(DataFormat format, out BufferRequirements bufferRequirements)
@@ -20,3 +21,4 @@ protected override NpgsqlCidr ReadCore(PgReader reader)
     protected override void WriteCore(PgWriter writer, NpgsqlCidr value)
         => NpgsqlInetConverter.WriteImpl(writer, (value.Address, value.Netmask), isCidr: true);
 }
+#pragma warning restore CS0618

src/Npgsql/Internal/ResolverFactories/NetworkTypeInfoResolverFactory.cs

@@ -48,11 +48,13 @@ static TypeInfoMappingCollection AddMappings(TypeInfoMappingCollection mappings)
                 static (options, mapping, _) => mapping.CreateInfo(options, new NpgsqlInetConverter()));
 
             // cidr
-            mappings.AddStructType<NpgsqlCidr>(DataTypeNames.Cidr,
-                static (options, mapping, _) => mapping.CreateInfo(options, new NpgsqlCidrConverter()), isDefault: true);
-
             mappings.AddStructType<IPNetwork>(DataTypeNames.Cidr,
-                static (options, mapping, _) => mapping.CreateInfo(options, new IPNetworkConverter()));
+                static (options, mapping, _) => mapping.CreateInfo(options, new IPNetworkConverter()), isDefault: true);
+
+#pragma warning disable CS0618 // NpgsqlCidr is obsolete
+            mappings.AddStructType<NpgsqlCidr>(DataTypeNames.Cidr,
+                static (options, mapping, _) => mapping.CreateInfo(options, new NpgsqlCidrConverter()));
+#pragma warning restore CS0618
 
             return mappings;
         }
@@ -77,8 +79,10 @@ static TypeInfoMappingCollection AddMappings(TypeInfoMappingCollection mappings)
             mappings.AddStructArrayType<NpgsqlInet>(DataTypeNames.Inet);
 
             // cidr
-            mappings.AddStructArrayType<NpgsqlCidr>(DataTypeNames.Cidr);
             mappings.AddStructArrayType<IPNetwork>(DataTypeNames.Cidr);
+#pragma warning disable CS0618 // NpgsqlCidr is obsolete
+            mappings.AddStructArrayType<NpgsqlCidr>(DataTypeNames.Cidr);
+#pragma warning restore CS0618
 
             return mappings;
         }

src/Npgsql/NpgsqlTypes/NpgsqlTypes.cs

@@ -488,6 +488,7 @@ static void CheckAddressFamily(IPAddress address)
 /// <remarks>
 /// https://www.postgresql.org/docs/current/static/datatype-net-types.html
 /// </remarks>
+[Obsolete("Use .NET IPNetwork instead of NpgsqlCidr to map to PostgreSQL cidr")]
 public readonly record struct NpgsqlCidr
 {
     public IPAddress Address { get; }

test/Npgsql.Tests/Types/NetworkTypeTests.cs

@@ -53,23 +53,23 @@ public Task IPAddress_Any()
         => AssertTypeWrite(IPAddress.Any, "0.0.0.0/32", "inet", NpgsqlDbType.Inet, skipArrayCheck: true);
 
     [Test]
-    public Task Cidr()
+    public Task IPNetwork_as_cidr()
         => AssertType(
-            new NpgsqlCidr(IPAddress.Parse("192.168.1.0"), netmask: 24),
+            new IPNetwork(IPAddress.Parse("192.168.1.0"), 24),
             "192.168.1.0/24",
             "cidr",
-            NpgsqlDbType.Cidr,
-            isDefaultForWriting: false);
+            NpgsqlDbType.Cidr);
 
+#pragma warning disable CS0618 // NpgsqlCidr is obsolete
     [Test]
-    public Task IPNetwork_as_cidr()
+    public Task NpgsqlCidr_as_Cidr()
         => AssertType(
-            new IPNetwork(IPAddress.Parse("192.168.1.0"), 24),
+            new NpgsqlCidr(IPAddress.Parse("192.168.1.0"), netmask: 24),
             "192.168.1.0/24",
             "cidr",
             NpgsqlDbType.Cidr,
-            isDefaultForWriting: false,
             isDefaultForReading: false);
+#pragma warning restore CS0618
 
     [Test]
     public Task Inet_v4_as_NpgsqlInet()