fix(postgrest): allow null reference values in Set

packages/Postgrest/Postgrest.Tests/Linq/LinqQueryTests.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text.Json.Nodes;
 using System.Threading.Tasks;
 using FluentAssertions;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
@@ -166,6 +167,43 @@ public async Task Set_ShouldUpdateOnlyTheAssignedColumns()
         record.IntValue.Should().Be(original.IntValue + 1);
     }
 
+    [TestMethod]
+    public async Task Set_ShouldClearOnlyTheMatchingRowsJsonColumn_GivenNull()
+    {
+        var client = LocalStack.Client();
+        var targetUsername = $"set-null-{Guid.NewGuid():N}";
+        var neighborUsername = $"{targetUsername}-neighbor";
+        await client.Table<UserWithJsonData>().Insert(new List<UserWithJsonData>
+        {
+            new() { Username = targetUsername, Data = new JsonObject { ["value"] = "target" } },
+            new() { Username = neighborUsername, Data = new JsonObject { ["value"] = "neighbor" } }
+        });
+
+        try
+        {
+            var updated = await client.Table<UserWithJsonData>()
+                .Where(user => user.Username == targetUsername)
+                .Set(user => user.Data!, null)
+                .Update(new QueryOptions { Returning = QueryOptions.ReturnType.Representation });
+            updated.Models.Should().ContainSingle().Which.Data.Should().BeNull();
+
+            var cleared = await client.Table<UserWithJsonData>()
+                .Where(user => user.Username == targetUsername)
+                .Filter("data", Operator.Is, "null").Single();
+            cleared.Should().NotBeNull();
+
+            var neighbor = await client.Table<UserWithJsonData>()
+                .Where(user => user.Username == neighborUsername).Single();
+            neighbor.Should().NotBeNull();
+            neighbor!.Data!["value"]!.GetValue<string>().Should().Be("neighbor");
+        }
+        finally
+        {
+            await client.Table<UserWithJsonData>()
+                .Where(user => user.Username == targetUsername || user.Username == neighborUsername).Delete();
+        }
+    }
+
     [TestMethod]
     public async Task Delete_ShouldRemoveRowsMatchingThePredicate()
     {

packages/Postgrest/Postgrest.Tests/Linq/SetClauseTests.cs

@@ -19,31 +19,66 @@ public class SetClauseTests
     private const string BaseUrl = "http://localhost:54321/rest/v1";
     private readonly Client client = new(BaseUrl);
 
+    [TestMethod]
+    public void Set_ShouldAcceptNull_GivenAReferenceTypeColumn()
+    {
+        var act = () => this.client.Table<KitchenSink>().Set(model => model.ListOfStrings!, null);
+        act.Should().NotThrow();
+    }
+
+    [TestMethod]
+    public void Set_ShouldAcceptNull_GivenAJsonObjectColumn()
+    {
+        var act = () => this.client.Table<UserWithJsonData>().Set(user => user.Data!, null);
+        act.Should().NotThrow();
+    }
+
+    [TestMethod]
+    public void Set_ShouldAcceptNull_GivenAStringColumn()
+    {
+        var act = () => this.client.Table<KitchenSink>().Set(model => model.StringValue!, null);
+        act.Should().NotThrow();
+    }
+
+    [TestMethod]
+    public void Set_ShouldAcceptNull_GivenANullableValueTypeColumn()
+    {
+        var act = () => this.client.Table<KitchenSink>().Set(model => model.IntValue!, null);
+        act.Should().NotThrow();
+    }
+
+    [TestMethod]
+    public void Set_ShouldThrow_GivenNullForANonNullableValueTypeColumn()
+    {
+        var act = () => this.client.Table<KitchenSink>().Set(model => model.BooleanValue, null);
+        act.Should().Throw<ArgumentException>();
+    }
+
     [TestMethod]
     public void Set_ShouldThrow_GivenAValueOfTheWrongType()
     {
-        var act = () => client.Table<Movie>().Set(x => x.Name!, DateTime.Now);
+        var act = () => this.client.Table<Movie>().Set(x => x.Name!, DateTime.Now);
         act.Should().Throw<ArgumentException>();
     }
 
     [TestMethod]
     public void Set_ShouldThrow_GivenAKeyThatIsNotAColumn()
     {
-        var act = () => client.Table<Movie>().Set(x => DateTime.Now, "value");
+        var act = () => this.client.Table<Movie>().Set(x => DateTime.Now, "value");
         act.Should().Throw<ArgumentException>();
     }
 
     [TestMethod]
     public void Set_ShouldThrow_GivenAKeyValuePairWithAMismatchedValueType()
     {
-        var act = () => client.Table<Movie>().Set(x => new KeyValuePair<object, object?>(x.Name!, DateTime.Now));
+        var act = () => this.client.Table<Movie>().Set(x => new KeyValuePair<object, object?>(x.Name!, DateTime.Now));
         act.Should().Throw<ArgumentException>();
     }
 
     [TestMethod]
     public void Set_ShouldThrow_GivenAKeyValuePairWhoseKeyIsNotAColumn()
     {
-        var act = () => client.Table<Movie>().Set(x => new KeyValuePair<object, object?>(DateTime.Now, "value"));
+        var act = () => this.client.Table<Movie>().Set(x => new KeyValuePair<object, object?>(DateTime.Now, "value"));
         act.Should().Throw<ArgumentException>();
     }
 }

packages/Postgrest/Postgrest.Tests/Models/UserWithJsonData.cs

@@ -0,0 +1,15 @@
+using System.Text.Json.Nodes;
+using Supabase.Postgrest.Attributes;
+using Supabase.Postgrest.Models;
+
+namespace Postgrest.Tests.Models;
+
+[Table("users")]
+public class UserWithJsonData : BaseModel
+{
+    [PrimaryKey("username", true)]
+    public string? Username { get; set; }
+
+    [Column("data")]
+    public JsonObject? Data { get; set; }
+}

packages/Postgrest/Postgrest.Tests/Writing/Data/UpdateApprovalTests.UpdateRequest_ShouldIncludeExplicitNull_GivenAJsonColumnSetToNull.verified.txt

@@ -0,0 +1 @@
+{"data":null}

packages/Postgrest/Postgrest.Tests/Writing/UpdateApprovalTests.cs

@@ -33,4 +33,13 @@ await this.Client.Table<Todo>().Filter("id", Operator.Equals, "1")
             .Update();
         await this.Verify(this.EmittedRequestBody).UseDirectory("Data");
     }
+
+    [TestMethod]
+    public async Task UpdateRequest_ShouldIncludeExplicitNull_GivenAJsonColumnSetToNull()
+    {
+        await this.Client.Table<UserWithJsonData>().Filter("username", Operator.Equals, "null-set-target")
+            .Set(user => user.Data!, null)
+            .Update();
+        await this.Verify(this.EmittedRequestBody).UseDirectory("Data");
+    }
 }

packages/Postgrest/Postgrest/Table.cs

@@ -481,7 +481,7 @@ public IPostgrestTable<TModel> Set(Expression<Func<TModel, object>> keySelector,
             throw new ArgumentException(
                 "Expression should return a KeyValuePair with a key of a Model Property and a value.");
 
-        if (value == null && visitor.ExpectedType != typeof(string))
+        if (value == null && visitor.ExpectedType.IsValueType)
         {
             if (Nullable.GetUnderlyingType(visitor.ExpectedType) == null)
                 throw new ArgumentException(