"non-existent variable" and "!=" expression should return false

[smartsl]

For example:

<script src="filtrex.2.2.0.min.js"></script>
<pre>
<script>
var fn1 = filtrex.compileExpression("x==1");
document.write('{x:1}:',fn1({x:1}),"\n"); //1
document.write('{x:2}:',fn1({x:2}),"\n"); //0
document.write('{y:1}:',fn1({y:1}),"\n"); //0

var fn2 = filtrex.compileExpression("x!=1");
document.write('{x:1}:',fn2({x:1}),"\n"); //0
document.write('{x:2}:',fn2({x:2}),"\n"); //1
document.write('{y:1}:',fn2({y:1}),"\n"); //1 (this should be 0)

var fn3 = filtrex.compileExpression("x!=1 and x!=null");
document.write('{x:1}:',fn3({x:1}),"\n"); //0
document.write('{x:2}:',fn3({x:2}),"\n"); //1
document.write('{y:1}:',fn3({y:1}),"\n"); //0 (this is ok)
</script>
</pre>

I can resolve this by using x!=1 and x!=null, but a little troublesome.

Could you provide a way to make that default false? Maybe add an option or something.

[cshaa]

Hey @smartsl!
Starting with Filtrex v3, trying to access an undefined property will result in an error (#22). However, also in Filtrex v3 you can overload any operator to do whatever you want (#30), so there should be a way for you to make Filtrex do whatever you need.

However, you should know that I don't think that x != 1 evaluating to false for anything else than { x: 1 } is good UX.