`Get` throwing Null Reference when one of the conditions in `Where` is a null validation

[EricWu91]

Bug report

Describe the bug

When there's a null validation in Where (not sure if that affects other cascading methods), it throws a NullReferenceException.

In the case below, it throws when Getis executed.

To Reproduce

Steps to reproduce the behavior, please provide code snippets or a repository:

await client
	.From<TTable>()
	.Select("*")
	.Where(x => requestModel.FilterPredicate == null || requestModel.FilterPredicate(x)) // Boom!
	.Get()

Stack trace:

System.NullReferenceException: Object reference not set to an instance of an object.
   at Supabase.Postgrest.Table`1.PrepareFilter(IPostgrestQueryFilter filter)
   at Supabase.Postgrest.Table`1.PrepareFilter(IPostgrestQueryFilter filter)
   at System.Linq.Enumerable.SelectListIterator`2.MoveNext()
   at Supabase.Postgrest.Table`1.GenerateUrl()
   at Supabase.Postgrest.Table`1.Send[TU](HttpMethod method, Object data, Dictionary`2 headers, CancellationToken cancellationToken, Boolean isInsert, Boolean isUpdate, Boolean isUpsert)
   at Supabase.Postgrest.Table`1.Get(CancellationToken cancellationToken)

Expected behavior

Where is supposed to evaluate the nullability of the FilterPredicate property and execute it if not null.

Debugging

In this screenshot, I followed the stack trace to see if I could understand the problem.
I noticed that visitor.Filter is filled with two Criteria: One is an "Equals" operation, the other is null.

My assumption is that this Criteria[1] is null because FilterPredicate is, in fact, null.
When any of the Criteria instances are null, though, it throws a NRE when it attempts to GenerateUrl(): (Table.cs:654)

The PrepareFilter method does not validate for a null IPostgrestQueryFilter filter, which happens when it is executed in the first recursive call, at line 786:

Workaround

Remove the null validation from the lazy call and do it outside Where:

var query =  client
    .From<TTable>()
	.Select("*");
			
    if (requestModel.FilterPredicate != null)
	{
	    query = query.Where(x => requestModel.FilterPredicate(x)); // Works
    }	

	var result = await query.Get();

Let me know if it's the expected behavior.

Thanks!

System information

• OS: Windows