test: remove duplicate test handlers and invalid callback pattern

- Remove duplicate callbackstringerror handler (same as stringerror)
- Remove callbackStringError test (strings are not valid for Lambda callbacks)
- Update test to use stringerror instead of callbackstringerror

Author: RaphaelManke

packages/instrumentation-aws-lambda/CHANGELOG.md

@@ -8,7 +8,7 @@
 * **instrumentation-aws-lambda:** Added runtime-aware handler support. The instrumentation automatically detects the Node.js runtime version from `AWS_EXECUTION_ENV` and adapts handler signatures accordingly:
   - **Node.js 24+**: Only Promise-based handlers are supported (callbacks deprecated by AWS Lambda)
   - **Node.js 22 and lower**: Both callback-based and Promise-based handlers are supported for backward compatibility
-  This ensures seamless operation across different Node.js runtime versions while respecting AWS Lambda's deprecation of callbacks in Node.js 24+.
+  This ensures seamless operation across different Node.js runtime versions while respecting AWS Lambda's removal of callbacks in Node.js 24+.
 
 ## [0.60.1](https://github.com/open-telemetry/opentelemetry-js-contrib/compare/instrumentation-aws-lambda-v0.60.0...instrumentation-aws-lambda-v0.60.1) (2025-11-24)
 

packages/instrumentation-aws-lambda/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@opentelemetry/instrumentation-aws-lambda",
-  "version": "0.61.0",
+  "version": "0.60.1",
   "description": "OpenTelemetry instrumentation for AWS Lambda function invocations",
   "main": "build/src/index.js",
   "types": "build/src/index.d.ts",

packages/instrumentation-aws-lambda/src/instrumentation.ts

@@ -520,11 +520,11 @@ export class AwsLambdaInstrumentation extends InstrumentationBase<AwsLambdaInstr
   private _wrapCallback(original: Callback, span: Span): Callback {
     const plugin = this;
     return function wrappedCallback(this: never, err, res) {
-      diag.debug('AWS Lambda instrumentation: Executing wrapped callback function');
+      plugin._diag.debug('executing wrapped callback function');
       plugin._applyResponseHook(span, err, res);
 
       plugin._endSpan(span, err, () => {
-        diag.debug('AWS Lambda instrumentation: Executing original callback function');
+        plugin._diag.debug('executing original callback function');
         return original.apply(this, [err, res]);
       });
     };

packages/instrumentation-aws-lambda/test/integrations/lambda-handler.test.ts

@@ -376,11 +376,11 @@ describe('lambda handler', () => {
   });
 
   it('should record string error in promise rejection', async () => {
-    initializeHandler('lambda-test/sync.callbackstringerror');
+    initializeHandler('lambda-test/sync.stringerror');
 
     let err: string;
     try {
-      await lambdaRequire('lambda-test/sync').callbackstringerror('arg', ctx);
+      await lambdaRequire('lambda-test/sync').stringerror('arg', ctx);
     } catch (e: any) {
       err = e;
     }

packages/instrumentation-aws-lambda/test/lambda-test/sync.js

@@ -32,10 +32,6 @@ exports.stringerror = async function (event, context) {
   throw 'handler error';
 };
 
-exports.callbackstringerror = async function (event, context) {
-  throw 'handler error';
-};
-
 exports.context = async function (event, context) {
   return api.trace.getSpan(api.context.active()).spanContext().traceId;
 };