JE.ApiValidation

Features

Standard error response DTO

• Clients shouldn't have to parse different response bodies to find out what went wrong.
  • 400 Bad Request will give back response bodies complying with the standard contract.
• Clients shouldn't have to parse text to figure out what sort of error happened.
  • errors have a unique integer ID, split into ranges to denote error classes

Request validation outside of your application logic

...(in a filter, or interceptor), making your code easier to understand.

Error processing outside of your application logic

... by running _validator.ValidateAndThrow(thingToProcess); - the ValidationException is caught and transformed to the standard error response DTO

Hooks to log errors

Each filter or interceptor has a virtual method to allow you to log a warning in your logging framework of choice.

Motivations

• API consumers want to be able to handle errors in a standard way
  • anything else is wasted time
    • implementing
    • debugging
    • supporting
    • operating

Development

Please follow the guidelines in CONTRIBUTING.md.

• CI
• To build, currently, use Visual Studio. We plan to open-source our build scripts, but haven't yet.

Getting Started

Framework agnostic

Request validation

0. Define your API contract as normal.
1. Define a class inheriting from AbstractValidator<TDto>.
2. Make that class visible to IoC.

-> validation will occur within model-binding, and if the DTO is invalid, a 400 Bad Request will result, with a standard error response, with code 40000.

Response processing rules errors

0. Define a class inheriting from AbstractValidator<TThingYouWantToApplyRulesTo>.
1. Make that class visible to IoC, take a dependency on it.
2. Call _validator.ValidateAndThrow(input); in your controller action or handler or service class, or wherever you need to apply rules.

-> A ValidationException will be thrown and caught & handled by the filter/interceptor, and a 400 Bad Request will result, with a standard error response, with code 45000.

WebApi

See the example in src/JE.ApiValidation.Examples.WebApi, and the tests for that in src/JE.ApiValidation.Examples.Tests.WebApi.

WebApi with StructureMapValidatorFectory

Register all implementations FluentValidation's AbstractValidators. These will then run automatically against any matching classes passed into ControllerActions.

See the example in src/JE.ApiValidation.Examples.WebApi.FluentValidation.StructureMap, and the tests for that in src/JE.ApiValidation.Examples.Tests.WebApi.

OpenRasta

See the example in src/JE.ApiValidation.Examples.OpenRasta, and the tests for that in src/JE.ApiValidation.Examples.Tests.OpenRasta.