public static void ExpressionsAreEqual(this Assert assert, Expression expected, Expression actual)
{
var success = Lambda.ExpressionsEqual(expected, actual);
Assert.IsTrue(success,
"The expressions didn't match." + NewLine + "Expected: {0}" + NewLine + "Actual: {1}",
expected.ToReadableString(),
actual.ToReadableString());
}
/// <summary>
/// Joins two binary lambda expressions using the 'And' conditional operator.
/// </summary>
/// <typeparam name="T">
/// The type of the predicate.
/// </typeparam>
/// <param name="left">
/// The left <see cref="Expression{TDelegate}" />.
/// </param>
/// <param name="right">
/// The right <see cref="Expression{TDelegate}" />.
/// </param>
/// <returns>
/// The resulting <see cref="Expression{TDelegate}" /> object that contains the joined
/// <see cref="Expression{TDelegate}" /> objects.
/// </returns>
public static Expression <Func <T, bool> > And <T>(this Expression <Func <T, bool> > left, Expression <Func <T, bool> > right)
{
Expression <Func <T, bool> > all = t => true;
if (Lambda.ExpressionsEqual(left, all))
{
return(right);
}
if (Lambda.ExpressionsEqual(right, all))
{
return(left);
}
var rightExprBody = new RebindParameterVisitor(right.Parameters[0], left.Parameters[0]).Visit(right.Body);
return(Expression.Lambda <Func <T, bool> >(Expression.AndAlso(left.Body, rightExprBody ?? throw new InvalidOperationException()), left.Parameters));
}
