Using RFC as ProblemDetails type #47

ofpinewood · Apr 25, 2020 · cc68834 · cc68834
1 parent 2774f7b
commit cc68834
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Showing 6 changed files with 57 additions and 9 deletions.
diff --git a/src/Opw.HttpExceptions.AspNetCore/Mappers/ProblemDetailsExceptionMapper.cs b/src/Opw.HttpExceptions.AspNetCore/Mappers/ProblemDetailsExceptionMapper.cs
@@ -154,10 +154,11 @@ protected virtual string MapDetail(TException exception, HttpContext context)
         /// </summary>
         /// <param name="exception">The exception.</param>
         /// <param name="context">The HTTP context.</param>
-        /// <returns>Returns the URI with the Exception type name ("error:[Type:slug]").</returns>
+        /// <returns>Returns the Exception.HelpLink or an URI with the Exception type name ("error:[Type:slug]").</returns>
         protected virtual string MapType(TException exception, HttpContext context)
         {
-            return new Uri($"error:{MapTitle(exception, context).ToSlug()}").ToString();
+            var url = exception.HelpLink ?? $"error:{MapTitle(exception, context).ToSlug()}";
+            return new Uri(url).ToString();
         }
     }
 }
diff --git a/src/Opw.HttpExceptions.AspNetCore/Mappers/ProblemDetailsHttpResponseMapper.cs b/src/Opw.HttpExceptions.AspNetCore/Mappers/ProblemDetailsHttpResponseMapper.cs
@@ -138,10 +138,19 @@ protected virtual string MapDetail(HttpResponse response)
         /// Map the ProblemDetails.Type property using the HTTP response.
         /// </summary>
         /// <param name="response">The HTTP response.</param>
-        /// <returns>Returns the URI with the HTTP status name ("error:[status:slug]").</returns>
+        /// <returns>Returns a status code information link (https://tools.ietf.org/html/rfc7231) or the URI with the HTTP status name ("error:[status:slug]").</returns>
         protected virtual string MapType(HttpResponse response)
         {
-            return new Uri($"error:{MapTitle(response).ToSlug()}").ToString();
+            string url = null;
+            try
+            {
+                ((HttpStatusCode)response.StatusCode).TryGetLink(out url);
+            }
+            catch { }
+
+            url ??= $"error:{MapTitle(response).ToSlug()}";
+
+            return new Uri(url).ToString();
         }
     }
 }
diff --git a/src/Opw.HttpExceptions/HttpException.cs b/src/Opw.HttpExceptions/HttpException.cs
@@ -29,7 +29,6 @@ public override string HelpLink
                 if (!string.IsNullOrWhiteSpace(_helpLink)) return _helpLink;
                 if (StatusCode.TryGetLink(out var link)) return link;
                 return ResponseStatusCodeLink.InternalServerError;
-
             }
             set => _helpLink = value;
         }

diff --git a/src/Opw.HttpExceptions/HttpStatusCodeExtensions.cs b/src/Opw.HttpExceptions/HttpStatusCodeExtensions.cs
@@ -3,9 +3,17 @@
 
 namespace Opw.HttpExceptions
 {
-    internal static class HttpStatusCodeExtensions
+    /// <summary>
+    /// Extension methods for HttpStatusCode.
+    /// </summary>
+    public static class HttpStatusCodeExtensions
     {
-        internal static bool TryGetLink(this HttpStatusCode statusCode, out string link)
+        /// <summary>
+        /// Try get a status code information link (https://tools.ietf.org/html/rfc7231).
+        /// </summary>
+        /// <param name="statusCode">HTTP status code.</param>
+        /// <param name="link">The status code information link.</param>
+        public static bool TryGetLink(this HttpStatusCode statusCode, out string link)
         {
             try
             {

diff --git a/tests/Opw.HttpExceptions.AspNetCore.Tests/Mappers/ProblemDetailsExceptionMapperTests.cs b/tests/Opw.HttpExceptions.AspNetCore.Tests/Mappers/ProblemDetailsExceptionMapperTests.cs
@@ -219,6 +219,25 @@ public void MapType_Should_ReturnFormattedExceptionName()
             result.Should().Be("error:divide-by-zero");
         }
 
+        [Fact]
+        public void MapType_Should_ReturnExceptionHelpLink()
+        {
+            var helpLink = "https://docs.microsoft.com/en-us/dotnet/api/system.exception.helplink?view=netcore-2.2";
+            var exception = new ApplicationException { HelpLink = helpLink };
+            var result = _mapper.MapType(exception, new DefaultHttpContext());
+
+            result.Should().Be(helpLink);
+        }
+
+        [Fact]
+        public void MapType_Should_ReturnExceptionHelpLinkForHttpException()
+        {
+            var exception = new BadRequestException();
+            var result = _mapper.MapType(exception, new DefaultHttpContext());
+
+            result.Should().Be(exception.HelpLink);
+        }
+
         private class ExposeProtectedProblemDetailsExceptionMapper : ProblemDetailsExceptionMapper<Exception>
         {
             public ExposeProtectedProblemDetailsExceptionMapper(IOptions<HttpExceptionsOptions> options) : base(options) { }

diff --git a/tests/Opw.HttpExceptions.AspNetCore.Tests/Mappers/ProblemDetailsHttpResponseMapperTests.cs b/tests/Opw.HttpExceptions.AspNetCore.Tests/Mappers/ProblemDetailsHttpResponseMapperTests.cs
@@ -126,11 +126,23 @@ public void MapTitle_Should_ReturnHttpStatus()
         }
 
         [Fact]
-        public void MapType_Should_ReturnFormattedHttpStatus()
+        public void MapType_Should_ReturnResponseStatusCodeLinkUnauthorized()
         {
             var result = _mapper.MapType(_unauthorizedHttpContext.Response);
 
-            result.Should().Be("error:unauthorized");
+            result.Should().Be(ResponseStatusCodeLink.Unauthorized);
+        }
+
+        [Fact]
+        public void MapType_Should_ReturnFormattedHttpStatus()
+        {
+            var teapotHttpContext = new DefaultHttpContext();
+            teapotHttpContext.Request.Path = "/api/test/i-am-a-teapot";
+            teapotHttpContext.Response.StatusCode = 418;
+
+            var result = _mapper.MapType(teapotHttpContext.Response);
+
+            result.Should().Be("error:418");
         }
 
         private class ExposeProtectedProblemDetailsHttpResponseMapper : ProblemDetailsHttpResponseMapper