fix(instrumentation-aws-lambda): handle non-configurable exports from esbuild CJS bundles

[RaphaelManke]

Summary

• When esbuild bundles ESM to CJS format, it defines exports using non-configurable accessor descriptors. OpenTelemetry's shimmer then fails with Cannot redefine property when trying to wrap the handler.
• Adds a makeExportsConfigurable() helper in the Lambda instrumentation's patch callback that replaces such exports with a new object having configurable data descriptors before shimmer attempts patching.

Fixes: open-telemetry/opentelemetry-lambda#1781
See: evanw/esbuild#2199

Steps to reproduce

Create a handler that uses the same non-configurable export pattern that esbuild emits when bundling ESM to CJS:

// index.js
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
Object.defineProperty(exports, "handler", {
  enumerable: true,
  get: function () { return handler; }
  // intentionally no configurable: true — this is what esbuild produces
});

async function handler(event) {
  return { statusCode: 200, body: JSON.stringify({ message: "OK" }) };
}

Deploy as a Lambda with the OTel layer and AWS_LAMBDA_EXEC_WRAPPER=/opt/otel-handler:

zip handler.zip index.js

aws lambda create-function \
  --function-name otel-cjs-repro \
  --runtime nodejs20.x \
  --role <execution-role-arn> \
  --handler index.handler \
  --zip-file fileb://handler.zip \
  --layers arn:aws:lambda:<region>:184161586896:layer:opentelemetry-nodejs-0_20_0:1 \
  --environment "Variables={AWS_LAMBDA_EXEC_WRAPPER=/opt/otel-handler}"

aws lambda invoke --function-name otel-cjs-repro \
  --cli-binary-format raw-in-base64-out \
  --payload '{}' response.json && cat response.json

Error (before fix):

{
  "errorType": "TypeError",
  "errorMessage": "Cannot redefine property: handler",
  "trace": [
    "TypeError: Cannot redefine property: handler",
    "    at Function.defineProperty (<anonymous>)",
    "    at T._wrap (...)",
    "    at Z.patch (...)",
    "    at T._onRequire (...)"
  ]
}

Root cause: esbuild emits exports as non-configurable accessor descriptors (see esbuild#2199), so Object.defineProperty in shimmer fails when trying to wrap the handler.

Test plan

• Added test/lambda-test/esbuild-cjs.js simulating esbuild's non-configurable export pattern
• Added integration tests verifying both success and error spans work with esbuild-style exports
• Verified tests fail without the fix (TypeError: Cannot redefine property: handler)
• Verified all 55 existing tests continue to pass
• Normal CJS exports (already configurable) return the same object without creating a copy

[raphael-theriault-swi]

Solution looks good, but I'm wondering whether we might want to tackle this from the instrumentation package given it's not technically unique to Lambda

[RaphaelManke]

Can you point me in a direction? I am not sure which instrumentation you are referring to? Like in the core repo?