chore: improved the comments

CONTRIBUTING.md

@@ -320,12 +320,19 @@ REGIONS=<region> SKIP_DOCKER_IMAGE=true BUILD_LAYER_WITH=local LAYER_NAME=experi
 ```
 ## ESM Support
 
+We have added the ESM support for all Node.js versions, Since version 18.19, [ESM loaders are off-thread](https://github.com/nodejs/node/pull/44710), loaded separately, a shift from previous setups where the Instana collector was loaded within the loader, leading to a disruption in existing implementation. To resolve this, we've replaced the deprecated `--experimental-loader` with `--import`, facilitating the loading of the collector in the main thread. However, note that `--import` is only compatible with Node.js v18.19 and later, necessitating the maintenance of both styles for different Node.js versions.
+
+Efforts are ongoing to integrate native ESM support, detailed in ref 117183.
+
 Use the following command to enable experimental ESM support:
 
 - For Node.js versions greater than or equal to 18.19:
 
- node --import /path/to/instana/node_modules/@instana/collector/register.mjs entry-point
-
+```sh
+node --import /path/to/instana/node_modules/@instana/collector/register.mjs entry-point
+```
 - For Node.js versions less than 18.19:
 
- node --experimental-loader /path/to/instana/node_modules/@instana/collector/esm-loader.mjs entry-point
+```sh
+node --experimental-loader /path/to/instana/node_modules/@instana/collector/esm-loader.mjs entry-point
+```

packages/aws-fargate/esm-loader.mjs

@@ -5,10 +5,12 @@
 'use strict';
 
 /**
- * We currently only instrument CJS modules. As soon as we want
- * to instrument ES modules (such as `got` v12), the requireHook will
- * no longer work. Therefor we would need to wrap the target ES module
- * with our instrumentations using the resolve & load hook.
+ * IMPORTANT NOTE: From Node.js version 18.19 and above, the ESM loaders operate off-thread.
+ * Consequently, ESM instrumentation using '--experimental-loader' becomes obsolete.
+ * Instead, we recommend using '--import' for loading instrumentation and relocating the 
+ * Instana collector loading to './register' file.
+ * Please note that '--import' flag is unavailable in earlier versions, hence we maintain both setups.
+ * We will incorporate the native ESM support by using 'import-in-the-middle'.
  *
  * Usage:
  * ENV NODE_OPTIONS='--experimental-loader=/instana/node_modules/
@@ -22,12 +24,3 @@
  */
 
 import './src/index.js';
-/*
-export async function resolve(specifier, context, nextResolve) {
- return nextResolve(specifier, context, nextResolve);
-}
-
-export async function load(url, context, nextLoad) {
- return nextLoad(url, context, nextLoad);
-}
-*/

packages/aws-fargate/register.mjs

@@ -3,17 +3,22 @@
  */
 
 /**
- * ESM hooks supplied via loaders (--experimental-loader=@instana/collector/esm-loader.mjs) run in a dedicated thread from v20 and above,
- * isolated from the main thread. Reference: https://github.com/nodejs/node/pull/44710
- * We loaded the tracer in the main thread with --import, we can extend the ESM hook with register method
- * in the future to extend the ESM support.
+ * As of Node.js version 18.19 and above, ESM loaders (--experimental-loader)
+ * are executed in a dedicated thread, separate from the main thread.
+ * see https://github.com/nodejs/node/pull/44710.
+ * Previously, loading the Instana collector within the loader and after the update ESM support
+ * no longer working with v18.19 and above. To address this, we've opted to load the Instana
+ * collector in the main thread using --import. 
+ * Additionally, we aim to incorporate native ESM
+ * support by utilizing the node register method, enabling customization of the ESM loader
+ * with 'import-in-the-middle'.
  *
  * Usage:
  * ENV NODE_OPTIONS='--import /instana/node_modules/@instana/aws-fargate/register.mjs
  */
-
+// We plan to utilize this for adding native ESM support in the near future
 // import { register } from 'node:module';
 // register(./loader.mjs, import.meta.url);
 
-// Importing the Instana trace initialization module here, as this is the main thread.
+// Importing the Instana trace initialization module here, as this is executed in the main thread.
 import './src/index.js';

packages/azure-container-services/esm-loader.mjs

@@ -5,10 +5,12 @@
 'use strict';
 
 /**
- * We currently only instrument CJS modules. As soon as we want
- * to instrument ES modules (such as `got` v12), the requireHook will
- * no longer work. Therefor we would need to wrap the target ES module
- * with our instrumentations using the resolve & load hook.
+ * IMPORTANT NOTE: From Node.js version 18.19 and above, the ESM loaders operate off-thread.
+ * Consequently, ESM instrumentation using '--experimental-loader' becomes obsolete.
+ * Instead, we recommend using '--import' for loading instrumentation and relocating the 
+ * Instana collector loading to './register' file.
+ * Please note that '--import' flag is unavailable in earlier versions, hence we maintain both setups.
+ * We will incorporate the native ESM support by using 'import-in-the-middle'.
  *
  * Usage:
  * ENV NODE_OPTIONS='--experimental-loader=/instana/node_modules/
@@ -22,12 +24,4 @@
  */
 
 import './src/index.js';
-/*
-export async function resolve(specifier, context, nextResolve) {
- return nextResolve(specifier, context, nextResolve);
-}
 
-export async function load(url, context, nextLoad) {
- return nextLoad(url, context, nextLoad);
-}
-*/

packages/azure-container-services/register.mjs

@@ -3,17 +3,22 @@
  */
 
 /**
- * ESM hooks supplied via loaders (--experimental-loader=@instana/collector/esm-loader.mjs) run in a dedicated thread from v20 and above,
- * isolated from the main thread. Reference: https://github.com/nodejs/node/pull/44710
- * We loaded the tracer in the main thread with --import, we can extend the ESM hook with register method
- * in the future to extend the ESM support.
+ * As of Node.js version 18.19 and above, ESM loaders (--experimental-loader)
+ * are executed in a dedicated thread, separate from the main thread.
+ * see https://github.com/nodejs/node/pull/44710.
+ * Previously, loading the Instana collector within the loader and after the update ESM support
+ * no longer working with v18.19 and above. To address this, we've opted to load the Instana 
+ * collector in the main thread using --import. Additionally, we aim to incorporate native ESM 
+ * support by utilizing the node register method, enabling customization of the ESM loader 
+ * with 'import-in-the-middle'.
  *
  * Usage:
  * ENV NODE_OPTIONS='--import /instana/node_modules/@instana/azure-container-services/register.mjs server.js
  */
 
+// We plan to utilize this for adding native ESM support in the near future
 // import { register } from 'node:module';
 // register(./loader.mjs, import.meta.url);
 
-// Importing the Instana trace initialization module here, as this is the main thread.
+// Importing the Instana trace initialization module here, as this is executed in the main thread.
 import './src/index.js';

packages/collector/esm-loader.mjs

@@ -5,10 +5,12 @@
 'use strict';
 
 /**
- * We currently only instrument CJS modules. As soon as we want
- * to instrument ES modules (such as `got` v12), the requireHook will
- * no longer work. Therefor we would need to wrap the target ES module
- * with our instrumentations using the resolve & load hook.
+ * IMPORTANT NOTE: From Node.js version 18.19 and above, the ESM loaders operate off-thread.
+ * Consequently, ESM instrumentation using '--experimental-loader' becomes obsolete.
+ * Instead, we recommend using '--import' for loading instrumentation and relocating the
+ * Instana collector loading to './register' file.
+ * Please note that '--import' flag is unavailable in earlier versions, hence we maintain both setups.
+ * We will incorporate the native ESM support by using 'import-in-the-middle'.
  *
  * Usage:
  * node --experimental-loader=@instana/collector/esm-loader.mjs server.js
@@ -19,13 +21,3 @@
 
 import instana from './src/index.js';
 instana();
-
-/*
-export async function resolve(specifier, context, nextResolve) {
- return nextResolve(specifier, context, nextResolve);
-}
-
-export async function load(url, context, nextLoad) {
- return nextLoad(url, context, nextLoad);
-}
-*/

packages/collector/register.mjs

@@ -3,18 +3,22 @@
  */
 
 /**
- * ESM hooks supplied via loaders (--experimental-loader=@instana/collector/esm-loader.mjs) run in a dedicated thread from v20 and above,
- * isolated from the main thread. Reference: https://github.com/nodejs/node/pull/44710
- * We loaded the tracer in the main thread with --import, we can extend the ESM hook with register method
- * in the future to extend the ESM support.
+ * As of Node.js version 18.19 and above, ESM loaders (--experimental-loader)
+ * are executed in a dedicated thread, separate from the main thread.
+ * see https://github.com/nodejs/node/pull/44710.
+ * Previously, loading the Instana collector within the loader and after the update ESM support
+ * no longer working with v18.19 and above. To address this, we've opted to load the Instana 
+ * collector in the main thread using --import. Additionally, we aim to incorporate native ESM 
+ * support by utilizing the node register method, enabling customization of the ESM loader 
+ * with 'import-in-the-middle'.
  *
  * Usage:
  * node --import @instana/collector/register.mjs server.js
  */
-
+// We plan to utilize this for adding native ESM support in the near future
 // import { register } from 'node:module';
 // register(./loader.mjs, import.meta.url);
 
-// Importing the Instana trace initialization module here, as this is the main thread.
+// Importing the Instana trace initialization module here, as this is executed in the main thread.
 import instana from './src/index.js';
 instana();

packages/google-cloud-run/esm-loader.mjs

@@ -5,10 +5,12 @@
 'use strict';
 
 /**
- * We currently only instrument CJS modules. As soon as we want
- * to instrument ES modules (such as `got` v12), the requireHook will
- * no longer work. Therefor we would need to wrap the target ES module
- * with our instrumentations using the resolve & load hook.
+ * IMPORTANT NOTE: From Node.js version 18.19 and above, the ESM loaders operate off-thread.
+ * Consequently, ESM instrumentation using '--experimental-loader' becomes obsolete.
+ * Instead, we recommend using '--import' for loading instrumentation and relocating the 
+ * Instana collector loading to './register' file.
+ * Please note that '--import' flag is unavailable in earlier versions, hence we maintain both setups.
+ * We will incorporate the native ESM support by using 'import-in-the-middle'.
  *
  * Usage:
  * ENV NODE_OPTIONS='--experimental-loader=/instana/node_modules/
@@ -21,12 +23,4 @@
  * can be invoked from this context.
  */
 
-import './src/index.js';
-/*
-export async function resolve(specifier, context, nextResolve) {
- return nextResolve(specifier, context, nextResolve);
-}
-export async function load(url, context, nextLoad) {
- return nextLoad(url, context, nextLoad);
-}
-*/
+import './src/index.js';

packages/google-cloud-run/register.mjs

@@ -3,17 +3,22 @@
  */
 
 /**
- * ESM hooks supplied via loaders (--experimental-loader=@instana/collector/esm-loader.mjs) run in a dedicated thread from v20 and above,
- * isolated from the main thread. Reference: https://github.com/nodejs/node/pull/44710
- * We loaded the tracer in the main thread with --import, we can extend the ESM hook with register method
- * in the future to extend the ESM support.
+ * As of Node.js version 18.19 and above, ESM loaders (--experimental-loader)
+ * are executed in a dedicated thread, separate from the main thread.
+ * see https://github.com/nodejs/node/pull/44710.
+ * Previously, loading the Instana collector within the loader and after the update ESM support
+ * no longer working with v18.19 and above. To address this, we've opted to load the Instana 
+ * collector in the main thread using --import. Additionally, we aim to incorporate native ESM 
+ * support by utilizing the node register method, enabling customization of the ESM loader 
+ * with 'import-in-the-middle'.
  *
  * Usage:
  * ENV NODE_OPTIONS='--import /instana/node_modules/@instana/google-cloud-run/register.mjs
  */
 
+// We plan to utilize this for adding native ESM support in the near future
 // import { register } from 'node:module';
 // register(./loader.mjs, import.meta.url);
 
-// Importing the Instana trace initialization module here, as this is the main thread.
+// Importing the Instana trace initialization module here, as this is executed in the main thread.
 import './src/index.js';