Add some tests to cover #186 conditions (#189)

Fix issue with a new extension method

sample/Ardalis.Result.Sample.Core/Services/BadResultService.cs

@@ -0,0 +1,11 @@
+namespace Ardalis.Result.Sample.Core.Services;
+
+public class BadResultService
+{
+    public Result ReturnErrorWithMessage(string message)
+    {
+        var result = Result.Error(message);
+        return result;
+    }
+
+}

sample/Ardalis.Result.Sample.Core/Services/WeatherServiceWithExceptions.cs

@@ -7,69 +7,67 @@
 using System.Linq;
 using System.Threading.Tasks;
 
-namespace Ardalis.Result.Sample.Core.Services
+namespace Ardalis.Result.Sample.Core.Services;
+public class WeatherServiceWithExceptions
 {
-    public class WeatherServiceWithExceptions
+    public WeatherServiceWithExceptions(IStringLocalizer<WeatherService> stringLocalizer)
     {
-        public WeatherServiceWithExceptions(IStringLocalizer<WeatherService> stringLocalizer)
-        {
-            _stringLocalizer = stringLocalizer;
-        }
+        _stringLocalizer = stringLocalizer;
+    }
 
-        private static readonly string[] Summaries = new[]
+    private static readonly string[] Summaries = new[]
 {
-            "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
-        };
+        "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
+    };
 
-        private IStringLocalizer<WeatherService> _stringLocalizer;
+    private IStringLocalizer<WeatherService> _stringLocalizer;
 
-        public Task<IEnumerable<WeatherForecast>> GetForecastAsync(ForecastRequestDto model)
+    public Task<IEnumerable<WeatherForecast>> GetForecastAsync(ForecastRequestDto model)
+    {
+        return Task.FromResult(GetForecast(model));
+    }
+
+    public IEnumerable<WeatherForecast> GetForecast(ForecastRequestDto model)
+    {
+        switch (model.PostalCode)
         {
-            return Task.FromResult(GetForecast(model));
+            case "NotFound":
+                throw new ForecastNotFoundException();
+            case "Conflict":
+                throw new ForecastConflictException();
         }
 
-        public IEnumerable<WeatherForecast> GetForecast(ForecastRequestDto model)
+        // validate model
+        if (model.PostalCode.Length > 10)
         {
-            switch (model.PostalCode)
+            throw new ForecastRequestInvalidException(new Dictionary<string, string>()
             {
-                case "NotFound":
-                    throw new ForecastNotFoundException();
-                case "Conflict":
-                    throw new ForecastConflictException();
-            }
+                { nameof(model.PostalCode), _stringLocalizer["PostalCode cannot exceed 10 characters."].Value }
+            });
+        }
 
-            // validate model
-            if (model.PostalCode.Length > 10)
+        // test single result value
+        if (model.PostalCode == "55555")
+        {
+            return new List<WeatherForecast>
             {
-                throw new ForecastRequestInvalidException(new Dictionary<string, string>()
+                new WeatherForecast
                 {
-                    { nameof(model.PostalCode), _stringLocalizer["PostalCode cannot exceed 10 characters."].Value }
-                });
-            }
+                    Date = DateTime.Now,
+                    TemperatureC = 0,
+                    Summary = Summaries[0]
+                }
+            };
+        }
 
-            // test single result value
-            if (model.PostalCode == "55555")
+        var rng = new Random();
+        return new List<WeatherForecast>(Enumerable.Range(1, 5)
+            .Select(index => new WeatherForecast
             {
-                return new List<WeatherForecast>
-                {
-                    new WeatherForecast
-                    {
-                        Date = DateTime.Now,
-                        TemperatureC = 0,
-                        Summary = Summaries[0]
-                    }
-                };
-            }
-
-            var rng = new Random();
-            return new List<WeatherForecast>(Enumerable.Range(1, 5)
-                .Select(index => new WeatherForecast
-                {
-                    Date = DateTime.Now.AddDays(index),
-                    TemperatureC = rng.Next(-20, 55),
-                    Summary = Summaries[rng.Next(Summaries.Length)]
-                })
-            .ToArray());
-        }
+                Date = DateTime.Now.AddDays(index),
+                TemperatureC = rng.Next(-20, 55),
+                Summary = Summaries[rng.Next(Summaries.Length)]
+            })
+        .ToArray());
     }
 }

sample/Ardalis.Result.Sample.UnitTests/ServiceTests/BadResultService_ReturnResultWithError.cs

@@ -0,0 +1,20 @@
+using System.Linq;
+using Ardalis.Result.Sample.Core.Services;
+using FluentAssertions;
+using Xunit;
+
+namespace Ardalis.Result.Sample.UnitTests.ServiceTests;
+
+public class BadResultService_ReturnResultWithError
+{
+   [Fact]
+    public void ReturnsErrorResultGivenMessage()
+    {
+        var service = new BadResultService();
+
+        var result = service.ReturnErrorWithMessage("Some error message");
+
+        result.Status.Should().Be(ResultStatus.Error);
+        result.Errors.Single().Should().Be("Some error message");
+    }
+}

src/Ardalis.Result/Result.Void.cs

@@ -64,6 +64,18 @@ public static Result<T> Success<T>(T value, string successMessage)
           };
         }
 
+        /// <summary>
+        /// Represents an error that occurred during the execution of the service.
+        /// A single error message may be provided and will be exposed via the Errors property.
+        /// </summary>
+        /// <param name="errorMessage"></param>
+        /// <returns></returns>
+        public static Result Error(string errorMessage)
+        {
+            return new Result(ResultStatus.Error) { Errors = new[] { errorMessage } };
+        }
+
+
         /// <summary>
         /// Represents the validation error that prevents the underlying service from completing.
         /// </summary>

tests/Ardalis.Result.UnitTests/ResultImplicitOperators.cs

@@ -1,3 +1,4 @@
+using System.Linq;
 using Xunit;
 
 namespace Ardalis.Result.UnitTests;
@@ -83,6 +84,17 @@ public void ConvertToNullObjectValue()
         Assert.Equal(expectedNullObject, result);
     }
 
+    [Fact]
+    public void ConvertResultResultToResult()
+    {
+        var result = Result.Error(expectedString);
+
+        Result convertedResult = result;
+
+        Assert.NotNull(convertedResult);
+        Assert.Equal(expectedString, convertedResult.Errors.First());
+    }
+
     public Result<T> DoBusinessOperationExample<T>(T testValue) => testValue;
     public T GetValueForResultExample<T>(Result<T> testResult) => testResult;