Evaluates API requests and responses against OpenAPI 3.1 specifications. Comes with a custom System.Net.Http.DelegatingHandler that can be used to intercept requests and responses when using an HttpClient.

dotnet add package Evaluation.OpenAPI

https://www.nuget.org/packages/Evaluation.OpenAPI/

Load the OpenAPI specification.

var stream = File.OpenRead("path/to/openapi-specification.json");
var document = JsonNode.Parse(stream);               
var specification = Specification.OpenAPI.Parse(document);

The OpenAPI class has extension methods that can evaluate HttpRequestMessage and HttpResponseMessage or by manually specifying request uri and method and provide content and headers.

See above how to load an OpenAPI specification.

var specification = ...
var evaluationOptions = new EvaluationOptions();
var client = new HttpClient(
    new OpenApiEvaluationHandler(
        specification,
        evaluationOptions,
        new HttpClientHandler()));

When sending a request the HttpResponseMessage will be wrapped by a EvaluationHttpResponseMessage that contains the evaluation results in the property EvaluationResults. If the HttpRequestMessage fails evaluation the handler will return a EvaluationHttpResponseMessage with a BadRequest response and never send the request to the server.

If you rather prefer failed evaluations to throw an exception, this can be configured with EvaluationOptions.

To load a yaml formatted specification, I recommend Yaml2JsonNode.

var yaml = new YamlStream();
using var reader = File.OpenText("path/to/openapi-specification.yaml");
yaml.Load(reader);
var document = yaml.ToJsonNode().First();

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

MIT