I have some methods that return PredicateExpressions built according to a few parameters.

I want to make unit tests for them and for that purpose I would like to make sure the PredicateExpression returned by the method contains exactly what I want.

I want to make sure the PredicateExpression contains 3 PredicateElements. 1- A FieldLikePredicate with specific values. 2- A Or operator 3- A FieldLikePredicate with specific values.

I tried the following but it dosent work.

           IPredicateExpressionElement elem = predicateExpression[0];
            if (elem.Type == PredicateExpressionElementType.Predicate)
            {
                FieldLikePredicate flp = elem as FieldLikePredicate;
            }

flp is always null.... I guess I'm not doing this right.

Thank you. Dave.

Hi Dave,

Could you debug and inspect the object at runtime to see what values and types are presented?

(Edit) I checked the manual. I forgot the property Contenst of a given IPredicateExpressionElement. Your code should look like:

foreach (IPredicateExpressionElement element in filter)
{
    switch (element.Type)
    {
        case PredicateExpressionElementType.Predicate:
            FieldLikePredicate flp = (FieldLikePredicate)element.Contents;
            Assert.AreEquals(expectedFieldName, flp.Field.Name);
            Assert.AreEquals(expectedPattern, flp.Pattern);
            break;

        case PredicateExpressionElementType.Operator:
            PredicateExpressionOperator oper = (PredicateExpressionOperator) element.Contents;
            Assert.AreEquals("Or", oper.ToString());
            break;
    }
}

Hope helpful

Thx for the reply. I had tried this but I was getting an System.InvalidCastException It turned out I had an other level of predicateExpression that I had to cast through first. The problem is now corrected.

Good