I have a complex class tree graph and was looking to autopopulate all properties with mock data. I have the following code
var faker = AutoInferRules<IATA_AIDX_FlightLegNotifRQ>();
var flight = faker.Generate();
static Faker<T> AutoInferRules<T>() where T : class, new()
{
var faker = new Faker<T>();
foreach (var property in typeof(T).GetProperties())
{
if (property.Name == "Schema")
{
continue;
}
try
{
if (property.PropertyType.IsClass && property.PropertyType != typeof(string))
{
// Recursively infer rules for nested classes
var nestedFaker = typeof(Program)
.GetMethod("AutoInferRules", BindingFlags.NonPublic | BindingFlags.Static)
?.MakeGenericMethod(property.PropertyType)
.Invoke(null, null);
faker = faker.RuleFor(property.Name, _ => nestedFaker);
}
else if (property.PropertyType == typeof(Double))
{
faker = faker.RuleFor(property.Name, (f, _) => f.Random.Double());
}
else if (property.PropertyType == typeof(Nullable<Boolean>))
{
faker = faker.RuleFor(property.Name, (f, _) => f.Random.Bool());
}
else if (property.PropertyType.IsGenericType &&
typeof(IList<>).IsAssignableFrom(property.PropertyType.GetGenericTypeDefinition()))
{
// Handle the case where the property is a List of objects
var elementType = property.PropertyType.GetGenericArguments()[0];
//gets definition for GenerateList<T> based on the type of the property
var generateListMethod = typeof(Program)
.GetMethods(BindingFlags.NonPublic | BindingFlags.Static).Last()
?.MakeGenericMethod(elementType);
var listExpression = Expression.Lambda<Func<T, List<T>>>(
Expression.Call(null, generateListMethod),
Expression.Parameter(typeof(T), "x")
);
faker = faker.RuleFor(property.Name,_ => listExpression);
}
else
{
// Generate rules for non-nested properties
faker = faker.RuleFor(property.Name, (f, _) => f.Random.AlphaNumeric(10));
}
}
catch (Exception ex)
{
Log.Logger.Error(ex, "error processing field {PropertyName}", property.Name);
}
}
return faker;
}
static List<T> GenerateList<T>() where T : class, new()
{
var faker = AutoInferRules<T>();
return new List<T> { faker.Generate() };
}
I get an error on the line:
faker = faker.RuleFor(property.Name,_ => listExpression);
The error is:
Expression of type 'System.Collections.Generic.List
1[RandomFlightDataGen.Model.IATA_AIDX_FlightLegNotifRQ.FlightLegType]' cannot be used for return type 'System.Collections.Generic.List1[RandomFlightDataGen.Model.IATA_AIDX_FlightLegNotifRQ.IATA_AIDX_FlightLegNotifRQ]
Which makes sense, because the initial call is with T where T is IATA_AIDX_FlightLegNotifRQ what I am unsure of is how do I for the Expression Lambda instead of using T use the type of the class on the property which I have inferred and created a MakeGenericMethod call for.