Added standaard configuration parm for configuring the serialization of null-properties when reading JSON from SQL query.

Author: fdij

src/ProgressOnderwijsUtils/Data/ParameterizedSqlObjectMapper.cs

@@ -1,6 +1,7 @@
 using System.Buffers;
 using System.ComponentModel.DataAnnotations.Schema;
 using System.Text.Json;
+using System.Text.Json.Serialization;
 using Microsoft.EntityFrameworkCore.Query;
 
 // ReSharper disable ConvertToUsingDeclaration
@@ -69,8 +70,8 @@ public static void ExecuteNonQuery(this ParameterizedSql sql, SqlConnection sqlC
         where T : IWrittenImplicitly
         => q.OfPocos<T>().Execute(sqlConn);
 
-    public static void ReadJson(this ParameterizedSql q, SqlConnection sqlConn, IBufferWriter<byte> buffer, JsonWriterOptions options)
-        => q.OfJson().Execute(sqlConn, buffer, options);
+    public static void ReadJson(this ParameterizedSql q, SqlConnection sqlConn, IBufferWriter<byte> buffer, JsonWriterOptions options, JsonIgnoreCondition defaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull)
+        => q.OfJson().Execute(sqlConn, buffer, options, defaultIgnoreCondition);
 
     /// <summary>
     /// Reads all records of the given query from the database, unpacking into a C# array of tuples in field order

src/ProgressOnderwijsUtils/Data/SqlBatch.cs

@@ -1,6 +1,7 @@
 using System.Buffers;
 using System.Data.Common;
 using System.Text.Json;
+using System.Text.Json.Serialization;
 
 namespace ProgressOnderwijsUtils;
 
@@ -211,8 +212,15 @@ public readonly record struct JsonSqlCommand(ParameterizedSql Sql, CommandTimeou
     public JsonSqlCommand WithTimeout(CommandTimeout timeout)
         => this with { CommandTimeout = timeout, };
 
-    public void Execute(SqlConnection conn, IBufferWriter<byte> buffer, JsonWriterOptions options)
+    public void Execute(SqlConnection conn, IBufferWriter<byte> buffer, JsonWriterOptions options, JsonIgnoreCondition defaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull)
     {
+        if (defaultIgnoreCondition is JsonIgnoreCondition.Always) {
+            throw new ArgumentException("The value cannot be 'Always'", nameof(defaultIgnoreCondition));
+        }
+        if (defaultIgnoreCondition is JsonIgnoreCondition.WhenWritingDefault) {
+            throw new NotSupportedException($"defaultIgnoreCondition {JsonIgnoreCondition.WhenWritingDefault} is not supported");
+        }
+
         using var cmd = this.ReusableCommand(conn);
         var reader = ExecuteReader(cmd);
         using var disposeReader = reader;
@@ -225,8 +233,12 @@ public void Execute(SqlConnection conn, IBufferWriter<byte> buffer, JsonWriterOp
         while (Read(cmd, reader)) {
             writer.WriteStartObject();
             for (var i = 0; i < table.Length; i++) {
-                if (!reader.IsDBNull(i)) {
-                    var name = table[i].ColumnName;
+                var name = table[i].ColumnName;
+                if (reader.IsDBNull(i)) {
+                    if (defaultIgnoreCondition is JsonIgnoreCondition.Never) {
+                        writer.WriteNull(name);
+                    }
+                } else {
                     var type = table[i].DataType;
                     var sqlType = table[i].DataTypeName;
                     if (type == typeof(bool)) {

src/ProgressOnderwijsUtils/ProgressOnderwijsUtils.csproj

@@ -1,8 +1,8 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <Import Project="..\NugetPackagesCommon.props" />
   <PropertyGroup Label="Configuration">
-    <Version>110.0.0</Version>
-    <PackageReleaseNotes>Update of NuGet packages.</PackageReleaseNotes>
+    <Version>110.1.0</Version>
+    <PackageReleaseNotes>Added standaard configuration parm for configuring the serialization of null-properties when reading JSON from SQL query.</PackageReleaseNotes>
     <Title>ProgressOnderwijsUtils</Title>
     <Description>Collection of utilities developed by ProgressOnderwijs</Description>
     <PackageTags>ProgressOnderwijs</PackageTags>

test/ProgressOnderwijsUtils.Tests/Data/ReadJsonTest.Null_properties_can_be_serialized_by_configuration.approved.txt

@@ -0,0 +1,30 @@
+[
+  {
+    "I": 1,
+    "S": "een"
+  },
+  {
+    "S": "twee"
+  },
+  {
+    "I": 2
+  },
+  {}
+][
+  {
+    "I": 1,
+    "S": "een"
+  },
+  {
+    "I": null,
+    "S": "twee"
+  },
+  {
+    "I": 2,
+    "S": null
+  },
+  {
+    "I": null,
+    "S": null
+  }
+]

test/ProgressOnderwijsUtils.Tests/Data/ReadJsonTest.cs

@@ -1,6 +1,7 @@
 using System.IO.Pipelines;
 using System.Text.Json;
 using System.Text.Json.Nodes;
+using System.Text.Json.Serialization;
 
 namespace ProgressOnderwijsUtils.Tests.Data;
 
@@ -217,4 +218,35 @@ ReadJsonPocoTestId int not null
             }
         }
     }
+
+    [Fact]
+    public void Null_properties_can_be_serialized_by_configuration()
+    {
+        SQL(
+            $"""
+            create table #ReadJsonNullsTest (
+                I int null
+                , S nvarchar(12) null
+            );
+            """
+        ).ExecuteNonQuery(Connection);
+
+        SQL(
+            $"""
+            insert into #ReadJsonNullsTest (I, S) values
+                (1, 'een')
+                , (null, 'twee')
+                , (2, null)
+                , (null, null)
+            """
+        ).ExecuteNonQuery(Connection);
+
+        var pipe = new Pipe();
+        SQL($"select t.* from #ReadJsonNullsTest t").ReadJson(Connection, pipe.Writer, new() { Indented = true, });
+        SQL($"select t.* from #ReadJsonNullsTest t").ReadJson(Connection, pipe.Writer, new() { Indented = true, }, JsonIgnoreCondition.Never);
+        pipe.Writer.Complete();
+
+        var json = Encoding.UTF8.GetString(pipe.Reader.ReadAsync().GetAwaiter().GetResult().Buffer);
+        ApprovalTest.CreateHere().AssertUnchangedAndSave(json);
+    }
 }