Example API Problem Return

api-with-problem.cs

using Microsoft.AspNetCore.Mvc;

namespace TestForAPIM.Controllers
{
    [ApiController]
    [Route("[controller]")]
    public class WeatherForecastController : ControllerBase
    {
        private static readonly string[] Summaries = new[]
        {
        "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
        };

        private readonly ILogger<WeatherForecastController> _logger;

        public WeatherForecastController(ILogger<WeatherForecastController> logger)
        {
            _logger = logger;
        }

        [HttpGet(Name = "GetWeatherForecast")]
        public async Task<ActionResult<IEnumerable<WeatherForecast>>> Get()
        {
            return Enumerable.Range(1, 5).Select(index => new WeatherForecast
            {
                Date = DateTime.Now.AddDays(index),
                TemperatureC = Random.Shared.Next(-20, 55),
                Summary = Summaries[Random.Shared.Next(Summaries.Length)]
            })
            .ToArray();
        }

        [ProducesResponseType(400)]
        [ProducesResponseType(typeof(WeatherForecast), 200)]
        [HttpPost(Name = "PostWeatherForecast")]
        public async Task<ActionResult<WeatherForecast>> Post([FromBody]WeatherForecast weatherForecast)
        {
            if(weatherForecast.Date < DateTime.Now)
            {
                return Problem(
                    title: "Forecast dates must be in the future",
                    statusCode: 400,
                    instance: HttpContext.Request.Path
                );
            }
            
            // Should save here in practice

            if(weatherForecast.TemperatureC > 30)
            {
                weatherForecast.Summary = "Feelin' hot hot hot!!!";
            }
            
            return weatherForecast;
        }
    }




}