NLogRequestPostedBodyMiddleware - Fixed handling of Stream.CanSeek

NLog · Jun 30, 2023 · 78b86bb · 78b86bb
1 parent 737ca2a
commit 78b86bb
Show file tree

Hide file tree

Showing 2 changed files with 43 additions and 5 deletions.
diff --git a/src/NLog.Web.AspNetCore/NLogRequestPostedBodyMiddleware.cs b/src/NLog.Web.AspNetCore/NLogRequestPostedBodyMiddleware.cs
@@ -97,8 +97,7 @@ private bool ShouldCaptureRequestBody(HttpContext context)
                 return false;
             }
 
-            // If we cannot seek the stream we cannot capture the body
-            if (!postedBody.CanSeek)
+            if (postedBody.Position != 0 && !postedBody.CanSeek)
             {
                 InternalLogger.Debug("NLogRequestPostedBodyMiddleware: HttpContext.Request.Body stream is non-seekable");
                 return false;
@@ -116,6 +115,13 @@ private bool ShouldCaptureRequestBody(HttpContext context)
         /// <returns>The contents of the Stream read fully from start to end as a String</returns>
         private static async Task<string> GetString(Stream stream)
         {
+            // If we cannot seek the stream we cannot capture the body
+            if (!stream.CanSeek)
+            {
+                InternalLogger.Debug("NLogRequestPostedBodyMiddleware: HttpContext.Request.Body stream is non-seekable");
+                return string.Empty;
+            }
+
             string responseText = null;
 
             // Save away the original stream position

diff --git a/tests/NLog.Web.AspNetCore.Tests/NLogRequestPostedBodyMiddlewareTests.cs b/tests/NLog.Web.AspNetCore.Tests/NLogRequestPostedBodyMiddlewareTests.cs
@@ -65,7 +65,6 @@ public void EmptyBodyTest()
             // Assert
             Assert.NotNull(defaultContext.Items);
             Assert.Empty(defaultContext.Items);
-            Assert.Null(defaultContext.Items[AspNetRequestPostedBodyLayoutRenderer.NLogPostedRequestBodyKey]);
         }
 
         [Fact]
@@ -86,7 +85,6 @@ public void ExcludContentTypeTest()
             // Assert
             Assert.NotNull(defaultContext.Items);
             Assert.Empty(defaultContext.Items);
-            Assert.Null(defaultContext.Items[AspNetRequestPostedBodyLayoutRenderer.NLogPostedRequestBodyKey]);
         }
 
         [Fact]
@@ -204,17 +202,51 @@ public void CannotSeekLengthTest()
             DefaultHttpContext defaultContext = new DefaultHttpContext();
 
             defaultContext.Request.Body = Substitute.For<Stream>();
-            defaultContext.Request.ContentLength = 1;
+            defaultContext.Request.ContentLength = 2;
             defaultContext.Request.ContentType = "text/plain";
 
             defaultContext.Request.Body.CanRead.Returns(true);
             defaultContext.Request.Body.CanSeek.Returns(false);
+            defaultContext.Request.Body.Length.Returns(2);
+            int firstCall = 2;
+            defaultContext.Request.Body.Read(default, default, default).ReturnsForAnyArgs(x => --firstCall);
+            defaultContext.Request.Body.ReadAsync(default, default, default).ReturnsForAnyArgs(x => --firstCall);
 
             // Act
             var middlewareInstance =
                 new NLogRequestPostedBodyMiddleware(Next,NLogRequestPostedBodyMiddlewareOptions.Default);
             middlewareInstance.Invoke(defaultContext).ConfigureAwait(false).GetAwaiter().GetResult();
 
+            // Assert
+            Assert.NotNull(defaultContext.Items);
+            Assert.Single(defaultContext.Items);
+            Assert.NotNull(defaultContext.Items[AspNetRequestPostedBodyLayoutRenderer.NLogPostedRequestBodyKey]);
+            Assert.True(defaultContext.Items[AspNetRequestPostedBodyLayoutRenderer.NLogPostedRequestBodyKey] is string);
+        }
+
+        [Fact]
+        public void CannotSeekLengthAndStartedTest()
+        {
+            // Arrange
+            DefaultHttpContext defaultContext = new DefaultHttpContext();
+
+            defaultContext.Request.Body = Substitute.For<Stream>();
+            defaultContext.Request.ContentLength = 2;
+            defaultContext.Request.ContentType = "text/plain";
+
+            defaultContext.Request.Body.CanRead.Returns(true);
+            defaultContext.Request.Body.CanSeek.Returns(false);
+            defaultContext.Request.Body.Position.Returns(1);    // Started
+            defaultContext.Request.Body.Length.Returns(2);
+            int firstCall = 2;
+            defaultContext.Request.Body.Read(default, default, default).ReturnsForAnyArgs(x => --firstCall);
+            defaultContext.Request.Body.ReadAsync(default, default, default).ReturnsForAnyArgs(x => --firstCall);
+
+            // Act
+            var middlewareInstance =
+                new NLogRequestPostedBodyMiddleware(Next, NLogRequestPostedBodyMiddlewareOptions.Default);
+            middlewareInstance.Invoke(defaultContext).ConfigureAwait(false).GetAwaiter().GetResult();
+
             // Assert
             Assert.NotNull(defaultContext.Items);
             Assert.Empty(defaultContext.Items);