watch: track worker thread dependencies in --watch mode for esm modules

Author: SudhansuBandha

lib/internal/modules/esm/loader.js

@@ -518,6 +518,19 @@ class ModuleLoader {
       const type = requestType === kRequireInImportedCJS ? 'require' : 'import';
       process.send({ [`watch:${type}`]: [url] });
     }
+    
+    // Relay Events from worker to main thread
+    if (process.env.WATCH_REPORT_DEPENDENCIES && !process.send) {
+      const { isMainThread } = internalBinding('worker');
+      if (isMainThread) {
+        return;
+      }
+      const { parentPort } = require('worker_threads');
+      if (!parentPort) {
+        return;
+      }
+      parentPort.postMessage({ 'watch:import': [url] });
+    }
 
     // TODO(joyeecheung): update the module requests to use importAttributes as property names.
     const importAttributes = resolveResult.importAttributes ?? request.attributes;

lib/internal/worker.js

@@ -347,6 +347,9 @@ class Worker extends EventEmitter {
         if (ArrayIsArray(message?.['watch:require'])) {
           process.send({ 'watch:require': message['watch:require'] });
         }
+        if (ArrayIsArray(message?.['watch:import'])) {
+          process.send({ 'watch:import': message['watch:import'] });
+        }
       });
     }
     this[kPort].postMessage({