Refactor bridge.js for lazy loading and boot sequence improvement

.github/workflows/ci.yml

@@ -64,7 +64,7 @@ jobs:
         os: [ubuntu-latest, windows-latest]
         include:
           - coverage: true
-            node-version: 20
+            node-version: latest
             os: ubuntu-latest
 
     steps:

lib/bridge.js

@@ -48,16 +48,24 @@ const Flatted = require('flatted'),
         __self = null; delete __self;
 
         // boot code starts hereafter
-        __uvm_setTimeout = setTimeout;
-        try {
-            ${bootCode};
-        } catch (error) {
-            __uvm_setTimeout(() => { throw error; }, 0);
-        }
+        // Post node v22.3.0, node uses undici's MessageEvent class which is
+        // loaded lazily and reads certain modules from the global scope when.
+        // loaded. We are doing a round trip to main thread to ensure the everything
+        // required for uvm to work is loaded before running the boot code, which
+        // might mutate the global scope.
+        __uvm_emit('${Flatted.stringify(['boot-ready.' + id])}');
+        bridge.once('boot-start', function () {
+            __uvm_timeout = setTimeout;
+            try {
+                ${bootCode};
+            } catch (error) {
+                __uvm_timeout(() => { throw error; }, 0);
+            }
 
-        __uvm_emit('${Flatted.stringify(['load.' + id])}');
-        __uvm_emit = null; delete __uvm_emit;
-        __uvm_setTimeout = null; delete __uvm_setTimeout;
+            __uvm_emit('${Flatted.stringify(['load.' + id])}');
+            __uvm_timeout = null; delete __uvm_timeout;
+            __uvm_emit = null; delete __uvm_emit;
+        });
         `;
     };
 
@@ -133,6 +141,17 @@ module.exports = function (bridge, options, callback) {
         callback(null, bridge);
     });
 
+    bridge.once('boot-ready.' + id, () => {
+        if (!worker) {
+            return callback(new Error('uvm : boot sequence failed due to worker termination.'));
+        }
+
+        worker.postMessage({
+            __emit_uvm: Flatted.stringify(['boot-start']),
+            __id_uvm: id
+        });
+    });
+
     // get firmware code string with boot code
     firmwareCode = sandboxFirmware(options.bootCode, id, options.debug);