RESTFulSense

I designed & developed this library as a wrapper around the existing .NET Core HttpClient implementation to provide the following values:

1. Meaningful Exceptions for APIs response status codes.

2. Simplified API communications.

3. Test-friendly implementation.

You can get RESTFulSense Nuget package by typing:

Install-Package RESTFulSense

Standard-Compliance

This library was built according to The Standard. The library follows engineering principles, patterns and tooling as recommended by The Standard.

This library is also a community effort which involved many nights of pair-programming, test-driven development and in-depth exploration research and design discussions.

Standard-Promise

The most important fulfillment aspect in a Standard complaint system is aimed towards contributing to people, its evolution, and principles. An organization that systematically honors an environment of learning, training, and sharing knowledge is an organization that learns from the past, makes calculated risks for the future, and brings everyone within it up to speed on the current state of things as honestly, rapidly, and efficiently as possible.

We believe that everyone has the right to privacy, and will never do anything that could violate that right. We are committed to writing ethical and responsible software, and will always strive to use our skills, coding, and systems for the good. We believe that these beliefs will help to ensure that our software(s) are safe and secure and that it will never be used to harm or collect personal data for malicious purposes.

The Standard Community as a promise to you is in upholding these values.

Details of what this library has to offer:

1. Meaningful Exceptions

RESTFulSense provide the following exceptions for erroring HTTP Status Codes as follows:

Status	Code	Exception
BadRequest	400	HttpResponseBadRequestException
Unauthorized	401	HttpResponseUnauthorizedException
PaymentRequired	402	HttpResponsePaymentRequiredException
Forbidden	403	HttpResponseForbiddenException
NotFound	404	HttpResponseNotFoundException
NotFound	404	HttpResponseUrlNotFoundException
MethodNotAllowed	405	HttpResponseMethodNotAllowedException
NotAcceptable	406	HttpResponseNotAcceptableException
ProxyAuthenticationRequired	407	HttpResponseProxyAuthenticationRequiredException
RequestTimeout	408	HttpResponseRequestTimeoutException
Conflict	409	HttpResponseConflictException
Gone	410	HttpResponseGoneException
LengthRequired	411	HttpResponseLengthRequiredException
PreconditionFailed	412	HttpResponsePreconditionFailedException
RequestEntityTooLarge	413	HttpResponseRequestEntityTooLargeException
RequestUriTooLong	414	HttpResponseRequestUriTooLongException
UnsupportedMediaType	415	HttpResponseUnsupportedMediaTypeException
RequestedRangeNotSatisfiable	416	HttpResponseRequestedRangeNotSatisfiableException
ExpectationFailed	417	HttpResponseExpectationFailedException
MisdirectedRequest	421	HttpResponseMisdirectedRequestException
UnprocessableEntity	422	HttpResponseUnprocessableEntityException
Locked	423	HttpResponseLockedException
FailedDependency	424	HttpResponseFailedDependencyException
UpgradeRequired	426	HttpResponseUpgradeRequiredException
PreconditionRequired	428	HttpResponsePreconditionRequiredException
TooManyRequests	429	HttpResponseTooManyRequestsException
RequestHeaderFieldsTooLarge	431	HttpResponseRequestHeaderFieldsTooLargeException
UnavailableForLegalReasons	451	HttpResponseUnavailableForLegalReasonsException
InternalServerError	500	HttpResponseInternalServerErrorException
NotImplemented	501	HttpResponseNotImplementedException
BadGateway	502	HttpResponseBadGatewayException
ServiceUnavailable	503	HttpResponseServiceUnavailableException
GatewayTimeout	504	HttpResponseGatewayTimeoutException
HttpVersionNotSupported	505	HttpResponseHttpVersionNotSupportedException
VariantAlsoNegotiates	506	HttpResponseVariantAlsoNegotiatesException
InsufficientStorage	507	HttpResponseInsufficientStorageException
LoopDetected	508	HttpResponseLoopDetectedException
NotExtended	510	HttpResponseNotExtendedException
NetworkAuthenticationRequired	511	HttpResponseNetworkAuthenticationRequiredException

2. Simplified API Communications

API controllers in ASP.NET Core today don't offer the full range of HTTP Codes that can be used to communicate certain events and errors to end users, in this library we managed to implement all the missing methods to communicate the full range of error codes as follows:

2.1 On Controller Level

Controller Method	Code
PaymentRequired(object value)	402
MethodNotAllowed(object value)	405
NotAcceptable(object value)	406
ProxyAuthenticationRequired(object value)	407
RequestTimeout(object value)	408
Gone(object value)	410
LengthRequired(object value)	411
PreconditionFailed(object value)	412
RequestEntityTooLarge(object value)	413
RequestUriTooLong(object value)	414
UnsupportedMediaType(object value)	415
RequestedRangeNotSatisfiable(object value)	416
ExpectationFailed(object value)	417
MisdirectedRequest(object value)	421
UnprocessableEntity(object value)	422
Locked(object value)	423
FailedDependency(object value)	424
UpgradeRequired(object value)	426
PreconditionRequired(object value)	428
TooManyRequests(object value)	429
RequestHeaderFieldsTooLarge(object value)	431
UnavailableForLegalReasons(object value)	451
InternalServerError(object value)	500
NotImplemented(object value)	501
BadGateway(object value)	502
ServiceUnavailable(object value)	503
GatewayTimeout(object value)	504
HttpVersionNotSupported(object value)	505
VariantAlsoNegotiates(object value)	506
InsufficientStorage(object value)	507
LoopDetected(object value)	508
NotExtended(object value)	510
NetworkAuthenticationRequired(object value)	511

This can be achieved by simply replacing the inheritance ControllerBase in your ASP.NET Core Controller class with RESTFulController as follows:

    [ApiController]
    [Route("api/[controller]")]
    public class ContactsController : RESTFulController
    {
        ...
    }

Once that's done, you will have full access to use any of the methods above to communicate more meaningful errors to your API consumers and clients.

2.2 On Consumer Level

Passing or retrieving objects from an API should be as simple as one method call, for RESTFulSense, you don't have to worry about how to serialize your input or deserialize the API output, here's how simple it works:

2.2.1 Initialization

The initialization of the RESTFulSense Client can be done in two different ways:

2.2.1.1 HttpClientFactory Approach

In your ASP.NET Core application, you can initialize the IRESTFulApiFactoryClient in your startup.cs as follows:

services.AddHttpClient<IRESTFulApiFactoryClient, RESTFulApiFactoryClient>(client => client.BaseAddress = new Uri(YOUR_API_URL));

2.2.1.2 Basic Initialization

You can also use the RESTFulClient simple initialize in a console app for instance as follows:

var apiClient = new RESTFulApiClient();

2.2.1 Deserialization

List<Student> students = 
    await restfulApiClient.GetContentAsync<List<Student>>(relativeUrl: "api/students");

2.2.2 Serialization

Student student = 
    await restfulApiClient.PostContentAsync<Student>(relativeUrl: "api/students", content: inputStudent); 

In addition to the wrappers around API calls and serialization/deserialization, this library also provides a simplified way to execute communications without any workarounds.

For instance, to execute a PUT API call without a body, to update a status for instance, you don't have to fake a PUT body to execute a successful call, you can just do the follows:

Account activatedAccount = 
    await restfulApiClient.PutContentAsync(relativeUrl: $"api/accounts/{accountId}/activate");

3. MultipartFormDataContent support

RESTFulSense allows you to easily convert a C# class with attributes into a MultipartFormDataContent and send it as a POST request using the PostFormAsync method.

The library includes the following attributes:

Attribute	Description
RESTFulByteArrayContentAttribute	Specifies a byte array content type
RESTFulStreamContentAttribute	Specifies a stream content type
RESTFulStringContentAttribute	Specifies a string content type
RESTFulFileNameAttribute	Adds a file name to the content

These attributes allow you to specify the content types and names of the form data. The RESTFulFileNameAttribute also allows you to add a file name to the content. Simply apply the attributes to your class properties and the library will handle the rest.

Here's an example usage:

public class FormUpload
{
    [RESTFulStreamContent(name: "file")]
    public Stream Stream { get; set; }

    [RESTFulStringContent(name: "purpose")]
    public string Purpose { get; set; }

    [RESTFulFileName(name: "file")]
    public string FileName { get; set; }
}

// ...

var formUpload = new FormUpload
{
    Stream = GetStream(),
    Purpose = "fine-tune",
    FileName = "SomeFile.jsonl"
};

var result = await PostFormAsync<FormUpload, ResultType>("https://example.com/upload", formUpload);

Note the linking of the FileName to the StreamContent via the name parameter in the attributes.

4. Custom serialization/deserialization support

RESTFulSense uses by default NewtonSoft serialization/deserialization support. However, in some scenarios this could present some drawbacks. Imagine:

1. Your models don´t have NewtonSoft annotations (because your main project doesn´t uses NewtonSoft).
2. You have some types which they need custom converters to specify how to deal with those types. For example, TimeOnly type. This type if you try serializate it with NewtonSoft or System.Text then raises an exception because it doesn´t know how to deal with it.
3. You need to use a custom JsonSerializerSettings or JsonSerializerOptions.

Here we have an example for a POST using System.Text.Json.JsonSerializer:

private readonly var jsonSerializerOptions =
    new JsonSerializerOptions
    {
    // ...
    };

private async ValueTask<string> Serialize<TContent>(TContent requestToSerialize)
{
    using var memoryStream = new MemoryStream();
    await JsonSerializer.SerializeAsync(memoryStream, requestToSerialize, jsonSerializerOptions);
    using var streamReader = new StreamReader(memoryStream, Encoding.UTF8);
    memoryStream.Position = 0;
    return streamReader.ReadToEnd();
}

private async ValueTask<TResult> Deserialize<TResult>(string responseToDeserialize)
{
    byte[] responseBytes = Encoding.UTF8.GetBytes(responseToDeserialize);
    using var memoryStream = new MemoryStream(responseBytes);
    var responseObject =
        await JsonSerializer.DeserializeAsync<TResult>(memoryStream, jsonSerializerOptions);

    return responseObject;
}

var result =
    await restfulApiClient.PostContentAsync<Student>(
        relativeUrl: "api/students",
        content: inputStudent,
        cancellationToken,
        mediaType: "text/json",
        ignoreDefaultValues: false,
        serializationFunction: Serialize<TContent>,
        deserializationFuntion: Deserialize<TResult>);

5. Testing-Friendly Implementation

RESTFulSense provides an interface to the API client class, to make it easier to mock and leverage dependency injection for the testability of the client consumers, here's an example:

var restfulApiClientMock = new Mock<IRestfulApiClient>();

restfulApiClient.Setup(client =>
    client.GetContentAsync<Student>(relativeUrl: $"api/students/{studentId}")
        .ReturnsAsync(student);

If you have any suggestions, comments or questions, please feel free to contact me on:

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Important Notice

This library is a community effort.

Huge thanks to Mr. Brian Parker @BrianLParker for his RESTfulSense Web Assembly effort.