We Keep Coding

Check coherence between route and body data during .NET Core validation

I'm trying to find the "best" way to check the coherence between data in the request URL and data in the body of the request.
For example, let's say we have this PUT endpoint:
https://host:port/foo/bar/{carId}
where I can pass a Car object as body:
class Car {
string CarId { get; set; }
string Brand { get; set; }
int MaxSpeed { get; set; }
...
}
Now, in my controller I have something like this:
[HttpPut("foo/bar/{carId}")]
public async Task updateCar([FromRoute] string carId, [FromBody] Car car) {
...
}
And I want to be sure that carId in the route matches the CarId property in the body.
What is the "best" way to achieve this? Of course I could simply check with an if in the body controller, but since this is a validation task (or at least I think so), I'd like to have this logic in my validation layer.
Personal ideas so far
Ok, the question is over, here I'll just put some ideas I've tried or I want to try.
I have a custom action filter to check the validation, and I'm trying to play with it in order to see if I can do something there, or add another custom action filter only where I want to check the coherence, but this doesn't look promising.
At the moment I've seen that in an action filter I have access to the controller method parameters through context.ActionArguments property, but I don't know how to check if these arguments were "bound arguments" (namely had some [FromXXX] attribute). If I could do this maybe I could check if there are arguments with the same name (or with a property with the same name), and then compare their values. But this seems very cumbersome and inconsistent.
I've read about custom binders, but I'm still scratching the surface (I hope to learn something more in the next few hours): can they be a possible solution?

You should do it like this:
[AttributeUsage(AttributeTargets.Property)]
public class VerifyWithRouteParams : Attribute
{
public string ParamName
{
get
{
return paramName;
}
}
private readonly string paramName;
public VerifyWithRouteParams(string paramName)
{
this.paramName = paramName;
}
}
Consider you have a car model that is being recieved through body:
public class Car
{
[VerifyWithRouteParams("carId")]
public string CarId { set; get; }
public string AnotherParam {set; get;}
}
You should have a default filter:
public class RouteBodyVerificationActionFilter : IActionFilter
{
public void OnActionExecuted(ActionExecutedContext context)
{
}
public void OnActionExecuting(ActionExecutingContext context)
{
// do something before the action executes
if (context.ActionArguments != null && context.ActionArguments.Count > 0)
{
foreach (var arg in context.ActionArguments)
{
if (arg.Value == null) continue;
bool isThereAnyObjectInArgumentsWithVerificationAttribute = arg.Value
.GetType()
.GetProperties()
.Any(
x => x.GetCustomAttributes(typeof(VerifyWithRouteParams), false).Any()
);
if (isThereAnyObjectInArgumentsWithVerificationAttribute)
{
foreach (var prop in arg.Value.GetType().GetProperties())
{
var verificationAttr = prop.GetCustomAttributes(typeof(VerifyWithRouteParams), false).FirstOrDefault() as VerifyWithRouteParams;
if (null == verificationAttr) continue;
string routeArgumentName = verificationAttr.ParamName;
context.ActionArguments.TryGetValue(routeArgumentName, out var routeArgumentValue);
if (null == routeArgumentValue)
{
context.ModelState.AddModelError("invalid argument value", routeArgumentName);
}
if (routeArgumentValue?.Equals(prop.GetValue(arg.Value)) != true)
{
context.ModelState.AddModelError("invalid argument value", routeArgumentName);
}
}
}
}
}
}
}
Then you should add a default filter in startup:
services.AddControllers(cfg =>
{
cfg.Filters.Add<RouteBodyVerificationActionFilter>();
});
Then you can check it by model validation errors in controller:
if (!ModelState.IsValid)
{
return Content("invalid model");
}

System.Text.Json JsonSerializer: Serialization and deserialization of 'System.Type' instances are not supported

I got an error related with security when I tried to deserialize by using `System.Text.Json JsonSerializer`.
What do I want to achieve?
I want to give the user controle to transalte some records in my database, so use can follow this scenario:
1- User can choose model of my class library.
2- After selecting a class, user will select a property(filed) from this class.
3- User will get list of values of the selected property up.
4- Last step is not here right now, user can edit a certian value.
This my piece of code:
MyPage.razor.cs:
[Inject]
private IGenericHttpClient<Type> HttpClient { get; set; }
private Type SelectedType { get; set; }
// First select a class [Class library] from HTML Select
private void OnTypeChnage(ChangeEventArgs args)
{
string FullName = "My.Models." + args.Value.ToString();
// Create type of selected class
SelectedType = Assemble.GetType(FullName, false);
}
//Call api to get all fields of this class
private async Task OnPropertChange(ChangeEventArgs args)
{
var list = await
HttpClient.GetJsonAsync($"/api/{SelectedType.Name}/all");
}
GenericHttpClient.cs
public async ValueTask<List<T>> GetJsonAsync(string url)
{
using HttpResponseMessage response = await _client.GetAsync(url);
ValidateResponse(response);
var conetnt = await response.Content.ReadAsStringAsync();
//I got the error down
return JsonSerializer.Deserialize<List<T>>(conetnt, new JsonSerializerOptions() { PropertyNameCaseInsensitive=true});
}

System.Text.Json does not support Type class due to security reasons. You send the full assembly name as a string and again try to construct the Type at the client end.

public async ValueTask<List<T>> GetJsonAsync(string url) this wont even compile, due to not specify generic information on method signature.
And also, your problem would come from the content of http response, otherwise, the Deserialize step should work fine.
I copied your code and make a small block that prove it.
// Define somewhere
public class GenericHttpClient
{
public List<T> GetJsonAsync<T>()
{
var content = "[{\"TestProp\": \"This is some test\"}]";
return JsonSerializer.Deserialize<List<T>>(content, new JsonSerializerOptions() { PropertyNameCaseInsensitive=true});
}
}
public class Test
{
public string TestProp { get; set; }
}
// Test it
var test = new GenericHttpClient();
var result = test.GetJsonAsync<Test>();

Like what #Mayur Ekbote mentioned up, "System.Text.Json does not support Type class due to security reasons." I will add a solution but I don't think this solution is very efficient.
Change Type to Dynamic:
[Inject]
private IGenericHttpClient<dynamic> HttpClient { get; set; }
Use JsonElement to get the value as a string:
private async Task OnPropertChange(ChangeEventArgs args)
{
var langCode = CultureInfo.CurrentCulture.Name;
PropertyValueList.Clear();
var list = await HttpClient.GetJsonAsync($"/api/{SelectedType.Name}/all");
List<object> listValue = new List<object>();
SelectedProperty = args.Value.ToString();
string fieldName = char.ToLower(SelectedProperty[0]) + SelectedProperty.Substring(1);
foreach (var item in list)
{
//Convert object to JsonElement
var val = ((JsonElement)item).GetProperty(fieldName).GetString();
PropertyValueList.Add(val);
}
}
Why is it not efficient?
Because I got a list of value String instead of list of selected class.

Dynamically Get and Set Properties on an EF Core Model

I'm learning C# and trying to find out how I can have a common method for updating different addresses that inherit from Address, and have an address type discriminator - PhysicalAddress and MailingAddress.
The example shows what I'd like to do if I could array access properties on models like you would in TypeScript. It indicates what I'm trying to do and have accomplished using two methods, but I haven't been able to figure out the way to achieve this in C#.
Any help, direction, or URL for referencing would be great. If this is not a good way to set up an update what would a properly single method update that would work with PerformUpdate.
// Example of an actual update method:
public async Task<int> PerformUpdate(User user, User updateUser) {
UpdateAddress(user, updateUser.PhysicalAddress);
UpdateAddress(user, updateUser.MailingAddress);
return await _context.SaveChangesAsync();
}
// Example of what I would like to achieve:
private void UpdateAddress(User user, Address newAddress)
{
// Currently would be: PhysicalAddress or MailingAddress
var addressType = newAddress.GetType().ToString();
// Dynamically access the address on the user based on the address type
Address oldAddress = user[addressType];
// Remove the old and add the new
if(oldAddress != null) {
_context.Addresses.Remove(oldAddress);
}
user[addressType] = newAddress;
}

I would look at the use case for this first, unless you have to support a truly huge number of classes it's probably better to create setters explicitly for each class you wish to support, for example with the is keyword. However, since you asked, we can abuse reflection to achieve this like so:
class Program
{
static void Main(string[] args)
{
var address = new PhysicalAddress();
var user = new User();
// this will set user.Address1 to address
SetAddress(user, address);
}
public static void SetAddress(User user, Address newAddress)
{
var fields = typeof(User).GetFields();
foreach (var fieldInfo in fields)
{
if (fieldInfo.FieldType == newAddress.GetType())
{
fieldInfo.SetValue(user, newAddress);
}
}
}
}
class User
{
public PhysicalAddress Address1;
public WorkAdress Address2;
}
class Address
{
}
class PhysicalAddress: Address
{
}
class WorkAdress: Address
{
}
```

Find a generic DbSet in a DbContext dynamically

I know this question has already been asked but I couldn't find an answer that satisfied me. What I am trying to do is to retrieve a particular DbSet<T> based on its type's name.
I have the following :
[assembly: System.Runtime.CompilerServices.InternalsVisibleTo("MyDllAssemblyName")]
[assembly: System.Runtime.CompilerServices.InternalsVisibleTo("MyCallingAssemblyName")]
class MyDbContext : DbContext {
public DbSet<ModelA> A { get; set; }
public DbSet<ModelB> B { get; set; }
public dynamic GetByName_SwitchTest(string name) {
switch (name) {
case "A": return A;
case "B": return B;
}
}
public dynamic GetByName_ReflectionTest(string fullname)
{
Type targetType = Type.GetType(fullname);
var model = GetType()
.GetRuntimeProperties()
.Where(o =>
o.PropertyType.IsGenericType &&
o.PropertyType.GetGenericTypeDefinition() == typeof(DbSet<>) &&
o.PropertyType.GenericTypeArguments.Contains(targetType))
.FirstOrDefault();
if (null != model)
return model.GetValue(this);
return null;
}
}
I have no trouble getting the type itself whether it is via a simple switch or reflection. I need however to return the type as a dynamic since I do not know what DbSet type it will be.
Then somewhere else in the same assembly, I use it this way :
// MyDbContext MyDbContextInstance..
var model = MyDbContextInstance.GetByName_SwitchTest("A");
var record1 = model.FirstOrDefault(); // It crashes here with RunTimeBinderException
At this point model contains an instance of a InternalDbSet<ModelA> type. From there, any use I do with the model object I get a RunTimeBinderException :
'Microsoft.Data.Entity.Internal.InternalDbSet' does not contain a definition for 'FirstOrDefault'
Investigating on the web, I found a blog post explaining that (dixit his blog) :
the reason the call to FirstOrDefault() fails is that the type
information of model is not available at runtime. The reason it's not
available is because anonymous types are not public. When the method
is returning an instance of that anonymous type, it's returning a
System.Object which references an instance of an anonymous type - a
type whose info isn't available to the main program.
And then he points that a solution :
The solution is actually quite simple. All we have to do is open up
AssemplyInfo.cs of the ClassLibrary1 project and add the following
line to it: [assembly:InternalsVisibleTo("assembly-name")]
I did try this solution on my code but it doesn't work. For info I have an asp.net 5 solution with two assemblies running on dnx dotnet46. An app and a dll containing all my models and DbContext. All the concerned calls I do are located on the dll though.
Does this solution have any chance to work ?
Am I missing something ?
Any pointers would be greatly appreciated ?
Thanks in advance
[EDIT]
I have tried to return IQueryable<dynamic> rather than dynamic and I could do the basic query model.FirstOrDefault(); but above all I'd like to be able to filter on a field too :
var record = model.FirstOrDefault(item => item.MyProperty == true);

So how did I do it when I am not aware of <T> during compile time.
First need to get the type as DbContext.Set method returns a non-generic DbSet instance for access to entities of the given type in the context and the underlying store.
public virtual DbSet Set(Type entityType)
Note here argument is the type of entity for which a set should be returned.And set for the given entity type is the return value.
var type = Assembly.GetExecutingAssembly().GetTypes().FirstOrDefault(t => t.Name == <Pass your table name>);
now once I have this type
if(type != null)
{
DbSet context = context.Set(type);
}
Or a one liner would be
DbSet mySet = context.Set(Type.GetType("<Your Entity Name>"));

*Disclaimer: This response doesn't give a stricto sensu answer to my question. It is rather a different approach to resolve my own problem. I am aware this is a specific example for a given situation that will not work for everyone. I am posting this approach in the hope it helps someone but will not mark it as the answer as I am still hoping for a real solution.
To start with, let's accept the fact that the only useful information we can get out of the current code is whether a record exists or not.. Any attempt of a dynamic queries after that would give the RuntimeBinderException.
Then let's continue with another fact; DbContext.Add(object) and DbContext.Update(object) are not template based so we can use them to save our models ( Instead of db.A.Add() or db.A.Update() )
In my own situation, no more is required to work out a procedure
Define models a little differently
To start with, I need a field that is retrievable across all my models which should obviously be a way to identify a unique record.
// IModel give me a reliable common field to all my models ( Fits my DB design maybe not yours though )
interface IModel { Guid Id { get; set; } }
// ModelA inherit IModel so that I always have access to an 'Id'
class ModelA : IModel {
public Guid Id { get; set; }
public int OtherField { get; set; }
}
// ModelB inherit IModel so that I always have access to an 'Id'
class ModelB : IModel {
public Guid Id { get; set; }
public string WhateverOtherField { get; set; }
}
Re-purpose the dynamic queries a bit to do something we know works
I haven't found a way to do smart query dynamically, so instead I know I can reliably identify a record and know if it exists or not.
class MyDbContext : DbContext {
public DbSet<ModelA> A { get; set; }
public DbSet<ModelB> B { get; set; }
// In my case, this method help me to know the next action I need to do
// The switch/case option is not pretty but might have better performance
// than Reflection. Anyhow, this is one's choice.
public bool HasRecord_SwitchTest(string name) {
switch (name) {
case "A": return A.AsNoTracking().Any(o => o.Id == id);
case "B": return B.AsNoTracking().Any(o => o.Id == id);
}
return false;
}
// In my case, this method help me to know the next action I need to do
public bool HasRecord_ReflectionTest(string fullname)
{
Type targetType = Type.GetType(fullname);
var model = GetType()
.GetRuntimeProperties()
.Where(o =>
o.PropertyType.IsGenericType &&
o.PropertyType.GetGenericTypeDefinition() == typeof(DbSet<>) &&
o.PropertyType.GenericTypeArguments.Contains(targetType))
.FirstOrDefault();
if (null != model)
return (bool)model.GetValue(this).AsNoTracking().Any(o => o.Id == id);
return false;
}
// Update and save immediately - simplified for example
public async Task<bool> UpdateDynamic(object content)
{
EntityEntry entry = Update(content, GraphBehavior.SingleObject);
return 1 == await SaveChangesAsync(true);
}
// Insert and save immediately - simplified for example
public async Task<bool> InsertDynamic(object content)
{
EntityEntry entry = Add(content, GraphBehavior.SingleObject);
return 1 == await SaveChangesAsync(true);
}
}
A little bit of plumbing to give a sense to my situation
Next, what I needed to do with that dynamic queries was a way to replicate data from a server down to my client. ( I have omitted a big chunk of the architecture to simplify this example )
class ReplicationItem
{
public ReplicationAction Action { get; set; } // = Create, Update, Delete
public string ModelName { get; set; } // Model name
public Guid Id { get; set; } // Unique identified across whole platform
}
Connecting the bits.
Now, here's the routine that connects the bits
public async void ProcessReplicationItem(ReplicationItem replicationItem)
{
using (var db = new MyDbContext())
{
// Custom method that attempts to get remote value by Model Name and Id
// This is where I get the strongly typed object
var remoteRecord = await TryGetAsync(replicationItem.ModelName, replicationItem.Id);
bool hasRemoteRecord = remoteRecord.Content != null;
// Get to know if a local copy of this record exists.
bool hasLocalRecord = db.HasRecord_ReflectionTest(replicationItem.ModelName, replicationItem.Id);
// Ensure response is valid whether it is a successful get or error is meaningful ( ie. NotFound )
if (remoteRecord.Success || remoteRecord.ResponseCode == System.Net.HttpStatusCode.NotFound)
{
switch (replicationItem.Action)
{
case ReplicationAction.Create:
{
if (hasRemoteRecord)
{
if (hasLocalRecord)
await db.UpdateDynamic(remoteRecord.Content);
else
await db.InsertDynamic(remoteRecord.Content);
}
// else - Do nothing
break;
}
case ReplicationAction.Update:
[etc...]
}
}
}
}
// Get record from server and with 'response.Content.ReadAsAsync' type it
// already to the appropriately
public static async Task<Response> TryGetAsync(ReplicationItem item)
{
if (string.IsNullOrWhiteSpace(item.ModelName))
{
throw new ArgumentException("Missing a model name", nameof(item));
}
if (item.Id == Guid.Empty)
{
throw new ArgumentException("Missing a primary key", nameof(item));
}
// This black box, just extrapolate a uri based on model name and id
// typically "api/ModelA/{the-guid}"
string uri = GetPathFromMessage(item);
using (var client = new HttpClient())
{
client.BaseAddress = new Uri("http://localhost:12345");
HttpResponseMessage response = await client.GetAsync(uri);
if (response.IsSuccessStatusCode)
{
return new Response()
{
Content = await response.Content.ReadAsAsync(Type.GetType(item.ModelName)),
Success = true,
ResponseCode = response.StatusCode
};
}
else
{
return new Response()
{
Success = false,
ResponseCode = response.StatusCode
};
}
}
}
public class Response
{
public object Content { get; set; }
public bool Success { get; set; }
public HttpStatusCode ResponseCode { get; set; }
}
ps: I am still interested in a real answer, so please keep posting for other answer if you have a real one to share.

You could use this to get the DBSet for a specific type:
public object GetByType(DbContextcontext, Type type) {
var methode = _context.GetType().GetMethod("Set", types: Type.EmptyTypes);
if (methode == null) {
return null;
}
return methode.MakeGenericMethod(type).Invoke(_context, null);
}

How to assign values to properties in moq?

I have a class with a method that returns an object of type User
public class CustomMembershipProvider : MembershipProvider
{
public virtual User GetUser(string username, string password, string email, bool isApproved)
{
return new User()
{
Name = username
,Password = EncodePassword(password)
,Email = email
,Status = (isApproved ? UsuarioStatusEnum.Ativo : UsuarioStatusEnum.ConfirmacaoPendente)
// ...
};
}
// ..
}
User is a domain object. Note the Id property with setter as protected:
public class User : IAuditable, IUser
{
public virtual int Id { get; protected set; }
public virtual string Name { get; set; }
public virtual string Email { get; set; }
public virtual UsuarioStatusEnum Status { get; set; }
public virtual string Password { get; set; }
}
Id is protected because it is generated by the database.
Test project
In my Test project I have a Fake repository with a method Store to save/update the object:
public void Store(T obj)
{
if (obj.Id > 0)
_context[obj.Id] = obj;
else
{
var generateId = _context.Values.Any() ? _context.Values.Max(p => p.Id) + 1 : 1;
var stubUser = Mock.Get<T>(obj); // In test, will always mock
stubUser.Setup(s => s.Id).Returns(generateId);
_context.Add(generateId, stubUser.Object);
}
}
In CustomMembershipProvider I have public override MembershipUser CreateUser method that calls the GetUser to create a User.
This way, all I have to do is mock the GetUser method so that the repository can generate the Id
var membershipMoq = new Mock<CustomMembershipProvider>();
membershipMoq.CallBase = true;
membershipMoq
.Setup(p => p.GetUser(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<bool>()))
.Returns<string, string, string, bool>( (username, password, email, isAproved) => {
var moqUser = new Mock<User>();
moqUser.Object.Name = username;
moqUser.Object.Password = password;
moqUser.Object.Email = email;
moqUser.Object.Status = (isAproved ? UsuarioStatusEnum.Ativo : UsuarioStatusEnum.ConfirmacaoPendente);
return moqUser.Object;
});
_membershipProvider = membershipMoq.Object;
Problem
In theory everything is correct. When CreateUser call 'GetUser' to create a user, the user will return Mock filled;
[TestMethod]
public void CreateUser_deve_criar_usuario_no_repositorio()
{
// Act
MembershipCreateStatus status;
var usr = _membershipProvider.CreateUser(
_fixture.Create<string>(),
_fixture.Create<string>(),
_fixture.Create<string>(),
null, null, true, null,
out status);
// usr should have name, email password filled. But not!
// Assert
status.Should().Be(MembershipCreateStatus.Success);
}
The problem is that Email, Name, Password are empty (with default values)!

The way you prepare the mocked user is the problem.
moqUser.Object.Name = username;
will not set the name, unless you have setup the mock properly.
Try this before assigning values to properties:
moqUser.SetupAllProperties();
This method will prepare all properties on the mock to be able to record the assigned value, and replay it later (i.e. to act as real property).
You can also use SetupProperty() method to set up individual properties to be able to record the passed in value.
Another approach is:
var mockUser = Mock.Of<User>( m =>
m.Name == "whatever" &&
m.Email == "someone#example.com");
return mockUser;

I think you are missing purpose of mocking. Mocks used to mock dependencies of class you are testing:
System under test (SUT) should be tested in isolation (i.e. separate from other units). Otherwise errors in dependencies will cause your SUTs tests to fail. Also you should not write tests for mocks. That gives you nothing, because mocks are not production code. Mocks are not executed in your application.
So, you should mock CustomMembershipProvider only if you are testing some unit, which depends on it (BTW it's better to create some abstraction like interface ICustomMembershipProvider to depend on).
Or, if you are writing tests for CustomMembershipProvider class, then it should not be mocked - only dependencies of this provider should be mocked.

Specifies that the all properties on the mock should have "property behavior",
meaning that setting their value will cause them to be saved and later returned when the properties is requested.
(This is also known as "stubbing".)
The default value for each property will be the one generated as specified by the
property for the mock.
mock.SetupAllProperties();