public void TestGetParameterWithMissingNestedProperty()
{
// GIVEN an expression for the parameter
ParameterExpression parameter = Expression.Parameter(typeof(TestClass));
// WHEN a param is requested with a nested property name missing from the object
// THEN an exception is thrown
ParameterProvider <TestClass> parameterProvider = new ParameterProvider <TestClass>(parameter, BindingFlags.Instance | BindingFlags.Public, NullCheckMode.None);
FormatStringSyntaxException e = Assert.ThrowsException <FormatStringSyntaxException>(() => parameterProvider.GetParameter("NestedTestClassProperty.NonExistent"));
Assert.AreEqual("Property 'NonExistent' not found on type 'FastStringFormat.Parsing.ParameterProviderTests+NestedTestClass'. Does it have a public get accessor?", e.Message);
}
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 TestGetParameter()
{
// GIVEN an expression for the parameter
ParameterExpression parameter = Expression.Parameter(typeof(TestClass));
// WHEN a param is requested and the null check mode is set to None
ParameterProvider <TestClass> parameterProvider = new ParameterProvider <TestClass>(parameter, BindingFlags.Instance | BindingFlags.Public, NullCheckMode.None);
Expression result = parameterProvider.GetParameter("StringProperty");
// THEN the returned expression is a method call
Assert.IsInstanceOfType(result, typeof(MethodCallExpression));
// AND the expression contains the correct parameter
Assert.AreSame(parameter, ((MethodCallExpression)result).Object);
// AND the expression contains the getter being accessed
MethodInfo?methodInfo = typeof(TestClass).GetProperty("StringProperty", BindingFlags.Instance | BindingFlags.Public)?.GetGetMethod();
Assert.AreSame(methodInfo, ((MethodCallExpression)result).Method);
}
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);
}