fluentvalidation-validator.cs

using System;
using System.Linq;
using System.Net;
using System.Threading.Tasks;
using FluentValidation;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore.Internal;
using Microsoft.Extensions.Logging;
using WidgetApi.Models;

namespace WidgetApi.FunctionHelpers
{
  public class FunctionWrapper<T> where T : ModelBase
  {
    private readonly BaseValidator<T> _validator;
    private readonly ILogger _log;

    public FunctionWrapper(BaseValidator<T> validator, ILogger<FunctionWrapper<T>> log)
    {
      _validator = validator;
      _log = log;
    }

    public async Task<IActionResult> Execute(T model, HttpRequest req, Func<Task<IActionResult>> azureFunction)
    {
      var results = await _validator.ValidateAsync(model, ruleSet: $"default,audit,{req.Method}");
      if (!results.IsValid)
      {
        var errors = results.Errors.Select(x => x.ErrorMessage).ToList();
        _log.LogWarning($"Model validation failed for type '{typeof(T).Name}'. Validation errors: [{errors.Join()}] ");
        return new ResponseEnvelopeResult<T>(HttpStatusCode.BadRequest, null, errors);
      }

      try
      {
        return await azureFunction();
      }
      catch (Exception e)
      {
        _log.LogError(e, "Unhandled exception occured in FunctionWrapper");
        return new ResponseEnvelopeResult<T>(HttpStatusCode.InternalServerError, null, new[] { e.Message });
      }
    }
  }
}