Fix Where clause with enum supabase-community/supabase-csharp#66

Postgrest/Linq/WhereExpressionVisitor.cs

@@ -59,7 +59,15 @@ protected override Expression VisitBinary(BinaryExpression node)
 			var left = Visit(node.Left);
 			var right = Visit(node.Right);
 
-			var column = left is MemberExpression leftMember ? GetColumnFromMemberExpression(leftMember) : null;
+			string? column = null;
+			if (left is MemberExpression leftMember)
+			{
+				column = GetColumnFromMemberExpression(leftMember);
+            }//To handle properly if it's a Convert ExpressionType generally with nullable properties
+			else if (left is UnaryExpression leftUnary && leftUnary.NodeType == ExpressionType.Convert && leftUnary.Operand is MemberExpression leftOperandMember)
+			{
+				column = GetColumnFromMemberExpression(leftOperandMember);
+			}
 
 			if (column == null)
 				throw new ArgumentException($"Left side of expression: '{node}' is expected to be property with a ColumnAttribute or PrimaryKeyAttribute");
@@ -129,7 +137,15 @@ protected override Expression VisitMethodCall(MethodCallExpression node)
 		/// <param name="constantExpression"></param>
 		private void HandleConstantExpression(string column, Operator op, ConstantExpression constantExpression)
 		{
-			Filter = new QueryFilter(column, op, constantExpression.Value);
+			if (constantExpression.Type.IsEnum)
+			{
+				var enumValue = constantExpression.Value;
+				Filter = new QueryFilter(column, op, enumValue);
+            }
+			else
+			{
+                Filter = new QueryFilter(column, op, constantExpression.Value);
+            }
 		}
 
 		/// <summary>
@@ -140,8 +156,8 @@ private void HandleConstantExpression(string column, Operator op, ConstantExpres
 		/// <param name="memberExpression"></param>
 		private void HandleMemberExpression(string column, Operator op, MemberExpression memberExpression)
 		{
-			Filter = new QueryFilter(column, op, GetMemberExpressionValue(memberExpression));
-		}
+            Filter = new QueryFilter(column, op, GetMemberExpressionValue(memberExpression));
+        }
 
 		/// <summary>
 		/// A unary expression parser (i.e. => x.Id == 1 &lt;- where both `1` is considered unary)
@@ -192,6 +208,10 @@ private void HandleNewExpression(string column, Operator op, NewExpression newEx
 			{
 				Filter = new QueryFilter(column, op, guid.ToString());
 			}
+			else if (instance.GetType().IsEnum)
+			{
+                Filter = new QueryFilter(column, op, instance);
+            }
 		}
 
 		/// <summary>

PostgrestTests/LinqTests.cs

@@ -98,6 +98,21 @@ public async Task TestLinqWhere()
             foreach (var q in query7.Models)
                 Assert.IsNotNull(q.DateTimeValue);
 
+            //Testing where condition with Enum as constant
+            var query8 = await client.Table<Movie>()
+                .Where(x => x.Status == MovieStatus.OnDisplay)
+                .Get();
+            foreach (var q in query8.Models)
+                Assert.IsTrue(q.Status == MovieStatus.OnDisplay);
+
+            //Test where condition with Enum as Memeber expression
+            var testMovie = new Movie { Status = MovieStatus.OnDisplay };
+            var query9 = await client.Table<Movie>()
+                .Where(x => x.Status == testMovie.Status)
+                .Get();
+            foreach (var q in query9.Models)
+                Assert.IsTrue(q.Status == MovieStatus.OnDisplay);
+
             await client.Table<KitchenSink>()
                 .Where(x => x.DateTimeValue == DateTime.Now)
                 .Get();

PostgrestTests/Models/LinkedModels.cs

@@ -12,12 +12,20 @@ public class Movie : BaseModel
 
     [Column("name")] public string? Name { get; set; }
 
+    [Column("status")] public MovieStatus? Status { get; set; }
+
     [Reference(typeof(Person), ReferenceAttribute.JoinType.Left)]
     public List<Person> People { get; set; } = new();
 
     [Column("created_at")] public DateTime CreatedAt { get; set; }
 }
 
+public enum MovieStatus
+{
+    OnDisplay,
+    OffDisplay
+}
+
 [Table("person")]
 public class Person : BaseModel
 {

PostgrestTests/db/00-schema.sql

@@ -75,7 +75,8 @@ CREATE TABLE public.movie
 (
     id         uuid                                 DEFAULT gen_random_uuid() PRIMARY KEY,
     created_at timestamp without time zone NOT NULL DEFAULT now(),
-    name       character varying(255)      NULL
+    name       character varying(255)      NULL,
+    status     character varying(255)      NULL
 );
 
 CREATE TABLE public.person

PostgrestTests/db/01-dummy-data.sql

@@ -53,12 +53,12 @@ VALUES ('f3ff356d-5803-43a7-b125-ba10cf10fdcd',
         '[20,50]'::int4range);
 
 
-insert into "public"."movie" ("created_at", "id", "name")
-values ('2022-08-20 00:29:45.400188', 'ea07bd86-a507-4c68-9545-b848bfe74c90', 'Top Gun: Maverick');
-insert into "public"."movie" ("created_at", "id", "name")
-values ('2022-08-22 00:29:45.400188', 'a972a8f6-2e23-4172-be8d-7b65470ca0f4', 'Mad Max: Fury Road');
-insert into "public"."movie" ("created_at", "id", "name")
-values ('2022-08-28 00:29:45.400188', '42fd15b1-3bff-431d-9fa5-314289beb246', 'Guns Away');
+insert into "public"."movie" ("created_at", "id", "name", "status")
+values ('2022-08-20 00:29:45.400188', 'ea07bd86-a507-4c68-9545-b848bfe74c90', 'Top Gun: Maverick', 'OnDisplay');
+insert into "public"."movie" ("created_at", "id", "name", "status")
+values ('2022-08-22 00:29:45.400188', 'a972a8f6-2e23-4172-be8d-7b65470ca0f4', 'Mad Max: Fury Road', 'OnDisplay');
+insert into "public"."movie" ("created_at", "id", "name", "status")
+values ('2022-08-28 00:29:45.400188', '42fd15b1-3bff-431d-9fa5-314289beb246', 'Guns Away', 'OffDisplay');
 
 
 insert into "public"."person" ("created_at", "first_name", "id", "last_name")