Exception thrown when filtering collection that contains null values

[austin-best]

Version

2.8.3

Details

Trying to filter on a collection of data where the property that I'm filtering on might contain null values.
A NullReferenceException is thrown if any of the values that I'm filtering on are null.

Steps to reproduce

Minimal reproducible example:

public class MyThing
{
	public string Name {get;set;}
	public string Mail {get;set;}
}

var myThings = new List<MyThing>()
{
        new MyThing() { Name = "Alpha", Mail = "[email protected]"},
        new MyThing() { Name = "Bravo", Mail = "[email protected]"},
        new MyThing() { Name = "Charlie", Mail = null},
}.AsQueryable();

var queryBuilder = new QueryBuilder<MyThing>();
queryBuilder.AddCondition("Mail$b.com/i");
var results = queryBuilder.Build(myThings).ToList(); // throws Null Reference Exception on materialization

Filters that throw an exception:

• [email protected]
• [email protected]/i (notice, this is case insensitive)
• Mail=*com

Filters that do not throw an exception:

• Mail=
• Mail!=
• [email protected] (notice, this is case sensitive)

[alirezanet]

Hi @austin-best,

What is your expected behavior? asking because you can add a null check if you want, for example these filters works correctly:

mail!=,mail$b.com/i
mail!=,mail$a.com
[email protected]
mail!=,mail=*com

mail!= you add this part if you want to also add a null check to your expression, however I will still look into this since personally I don't like to see null reference exceptions anywhere 😊.

I had an idea before to add a null safe search settings that always checks for null values before creating actual expressions but since so far no one asked for it It doesn't exist. please let me know what you think

[austin-best]

Hi, @alirezanet -
The null check works, and I'm able to work that into my logic.

I would have expected nulls to have been handled as falsey for any operator except mail!=. Now that I know, I can work around it with the null checks in the filters, but the opt-in to change the behavior would be appreciated.

[alirezanet]

I agree, would be a nice additional feature... I'll add it probably in the future versions.
thanks for the feedback