public void TestWrapWithNullCheckWithNoneNullable()
{
// GIVEN an expression for the parameter
ParameterExpression parameter = Expression.Parameter(typeof(TestClass));
// AND a nullable expression
Expression nullableExpression = Expression.Constant(10);
Expression processedExpression = Expression.Constant("Hello");
// WHEN wrapping a nullable
ParameterProvider <TestClass> parameterProvider = new ParameterProvider <TestClass>(parameter, BindingFlags.Instance | BindingFlags.Public, NullCheckMode.None);
Expression result = parameterProvider.WrapWithNullCheck(nullableExpression, processedExpression);
// THEN the returned expression is the processedExpression
Assert.AreSame(processedExpression, result);
}
public void TestWrapWithNullCheckWithUseEmptyStringNullCheckModeAndReferenceType()
{
// GIVEN expressions for parameters
ParameterExpression parameter = Expression.Parameter(typeof(TestClass));
// AND a nullable expression
Expression nullableExpression = Expression.Constant(new object());
Expression processedExpression = Expression.Constant("Hello");
// WHEN the null check mode is set to UseEmptyString and we pass a referenec type
ParameterProvider <TestClass> parameterProvider = new ParameterProvider <TestClass>(parameter, BindingFlags.Instance | BindingFlags.Public, NullCheckMode.UseEmptyString);
Expression result = parameterProvider.WrapWithNullCheck(nullableExpression, processedExpression);
// THEN the returned expression is a conditional
Assert.IsInstanceOfType(result, typeof(ConditionalExpression));
// AND the test is an equals comparison against null
Expression test = ((ConditionalExpression)result).Test;
Assert.IsInstanceOfType(test, typeof(BinaryExpression));
Assert.AreEqual(ExpressionType.Equal, ((BinaryExpression)test).NodeType);
Assert.AreSame(nullableExpression, ((BinaryExpression)test).Left);
Assert.IsInstanceOfType(((BinaryExpression)test).Right, typeof(ConstantExpression));
Assert.IsNull(((ConstantExpression)((BinaryExpression)test).Right).Value);
// AND the true branch is a constant of an empty string
Expression trueBranch = ((ConditionalExpression)result).IfTrue;
Assert.IsInstanceOfType(trueBranch, typeof(ConstantExpression));
Assert.AreEqual("", ((ConstantExpression)trueBranch).Value);
// AND the false branch is the processed expression
Expression falseBranch = ((ConditionalExpression)result).IfFalse;
Assert.AreSame(processedExpression, falseBranch);
}