Instrumenation.AWSLambda: Drop netstandard2, lose Newtonsoft (non-)dependency

src/OpenTelemetry.Instrumentation.AWSLambda/CHANGELOG.md

@@ -2,6 +2,23 @@
 
 ## Unreleased
 
+* The minimum required .NET version is now .NET Core 3.1 (previously any
+  netstandard2.0-compliant). As the minimum .NET version in AWS Lambda is
+  already 6.0, no compatibility problems are expected.
+* As part of the switch to .NET Core 3.1, the package no longer uses
+  Newtonsoft.Json but the built-in System.Text.Json.
+
+  This resolves a warning that some dependency analyzers may produce where this
+  package would transitively depend on a vulnerable version of Newtonsoft.Json
+  through [Amazon.Lambda.APIGatewayEvents][].
+
+  This also avoids a potential issue where the instrumentation would try to call
+  a Newtonsoft.Json function when no other package nor the app itself depends on
+  Newtonsoft.Json, since the transitive dependency would be ignored unless using
+  application were compiled against a TargetFramework older than Core 3.1.
+
+[Amazon.Lambda.APIGatewayEvents]: https://www.nuget.org/packages/Amazon.Lambda.APIGatewayEvents/2.4.1#dependencies-body-tab
+
 ## 1.1.0-beta.3
 
 Released 2023-Jun-13

src/OpenTelemetry.Instrumentation.AWSLambda/Implementation/AWSMessagingUtils.cs

@@ -18,9 +18,9 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Text.Json;
 using Amazon.Lambda.SNSEvents;
 using Amazon.Lambda.SQSEvents;
-using Newtonsoft.Json;
 using OpenTelemetry.Context.Propagation;
 
 namespace OpenTelemetry.Instrumentation.AWSLambda.Implementation;
@@ -144,11 +144,11 @@ private static SNSEvent.SNSMessage GetSnsMessage(SQSEvent.SQSMessage sqsMessage)
         var body = sqsMessage.Body;
         if (body != null &&
             body.TrimStart().StartsWith("{", StringComparison.Ordinal) &&
-            body.Contains(SnsMessageAttributes))
+            body.Contains(SnsMessageAttributes, StringComparison.Ordinal))
         {
             try
             {
-                snsMessage = JsonConvert.DeserializeObject<SNSEvent.SNSMessage>(body);
+                snsMessage = JsonSerializer.Deserialize<SNSEvent.SNSMessage>(body);
             }
             catch (Exception)
             {

src/OpenTelemetry.Instrumentation.AWSLambda/OpenTelemetry.Instrumentation.AWSLambda.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
     <Description>AWS Lambda tracing wrapper for OpenTelemetry .NET</Description>
     <PackageTags>$(PackageTags);AWS Lambda</PackageTags>
     <MinVerTagPrefix>Instrumentation.AWSLambda-</MinVerTagPrefix>

src/Shared/Guard.cs

@@ -34,7 +34,7 @@
 #pragma warning disable SA1403 // File may only contain a single namespace
 #pragma warning disable SA1649 // File name should match first type name
 
-#if !NET6_0_OR_GREATER
+#if !NETCOREAPP3_0_OR_GREATER
 namespace System.Runtime.CompilerServices
 {
     /// <summary>Allows capturing of the expressions passed to a method.</summary>

test/OpenTelemetry.Instrumentation.AWSLambda.Tests/Implementation/AWSMessagingUtilsTests.cs

@@ -72,6 +72,47 @@ public void ExtractParentContext_SetParentFromMessageBatchIsEnabled_ParentIsSetF
         Assert.Equal(2, links.Count());
     }
 
+    [Fact]
+    public void ExtractParentContext_SetParentFromMessageBatchIsEnabled_ParentIsSetFromSnsMessage()
+    {
+        AWSMessagingUtils.SetParentFromMessageBatch = true;
+        var sqsEvent = new SQSEvent
+        {
+            Records = new List<SQSMessage>
+            {
+                new SQSMessage
+                {
+                    MessageAttributes = new(),
+
+#pragma warning disable format // dotnet-format butchers the raw string & all following code (use dotnet format instead?)
+                    Body = /*lang=json,strict*/ """
+                    {
+                      "Type" : "Notification",
+                      "MessageId" : "f91f7f8e-77cc-51e7-ad08-231055044066",
+                      "TopicArn" : "arn:aws:sqs:us-east-1:123456789012:foo-bar-test-queue",
+                      "Subject" : "testsub",
+                      "Message" : "{\"This JSON string\": \"is in the SNS body\"}",
+                      "Timestamp" : "2023-03-29T11:27:04.056Z",
+                      "SignatureVersion" : "1",
+                      "Signature" : "base64string/redacted",
+                      "SigningCertURL" : "https://sns.us-east-1.amazonaws.com/SimpleNotificationService-1234567abc123def1234567890123467.pem",
+                      "UnsubscribeURL" : "https://sns.us-east-1.amazonaws.com/?Action=Unsubscribe&SubscriptionArn=arn:aws:sqs:us-east-1:123456789012:foo-bar-test-queue:123abcde-1234-1abc-1234-123456abcdef",
+                      "MessageAttributes" : {
+                        "traceparent" : {"Type":"String","Value":"00-0af7651916cd43dd8448eb211c80319c-b9c7c989f97918e1-00"}
+                      }
+                    }
+                    """,
+                },
+            },
+        };
+
+        (PropagationContext parentContext, IEnumerable<ActivityLink> links) = AWSMessagingUtils.ExtractParentContext(sqsEvent);
+
+        Assert.NotEqual(default, parentContext);
+        Assert.Equal(SpanId1, parentContext.ActivityContext.SpanId.ToHexString());
+        Assert.Single(links);
+    }
+
     private static SQSEvent CreateSqsEventWithMessages(string[] spans)
     {
         var @event = new SQSEvent { Records = new List<SQSMessage>() };