Simplify pthread_esm_startup. NFC (#27016)

Author: sbc100

src/pthread_esm_startup.mjs

@@ -10,7 +10,7 @@
 // until the wasm memory has been received via postMessage.
 
 #if RUNTIME_DEBUG
-console.log("Running pthread_esm_startup");
+console.log('Running pthread_esm_startup');
 #endif
 
 #if ENVIRONMENT_MAY_BE_NODE
@@ -34,25 +34,28 @@ self.onmessage = async (msg) => {
 #if RUNTIME_DEBUG
   console.log('pthread_esm_startup', msg.data.cmd);
 #endif
-  if (msg.data.cmd == 'load') {
-    // Until we initialize the runtime, queue up any further incoming messages
-    // that can arrive while the async import (await import below) is happening.
-    // For examples the `run` message often arrives right away before the import
-    // is complete.
-    let messageQueue = [msg];
-    self.onmessage = (e) => messageQueue.push(e);
-
-    // Now that we have the wasmMemory we can import the main program
-    globalThis.wasmMemory = msg.data.wasmMemory;
-    const prog = await import('./{{{ TARGET_JS_NAME }}}');
-
-    // Now that the import is completed the main program will have installed
-    // its own `onmessage` handler and replaced our handler.
-    // Now we can dispatch any queued messages to this new handler.
-    for (const msg of messageQueue) {
-      await self.onmessage(msg);
-    }
-
-    await prog.default()
+
+  // Until we initialize the runtime, queue up any further incoming messages
+  // that can arrive while the async import (await import below) is happening.
+  // For examples the `run` message often arrives right away before the import
+  // is complete.
+#if ASSERTIONS
+  if (!msg.data.wasmMemory) console.error('first message should include wasmMemory');
+#endif
+
+  const messageQueue = [msg];
+  self.onmessage = (e) => messageQueue.push(e);
+
+  // Now that we have the wasmMemory we can import the main program
+  globalThis.wasmMemory = msg.data.wasmMemory;
+  const prog = await import('./{{{ TARGET_JS_NAME }}}');
+
+  // Now that the import is completed the main program will have installed
+  // its own `onmessage` handler and replaced our handler.
+  // Now we can dispatch any queued messages to this new handler.
+  for (const msg of messageQueue) {
+    await self.onmessage(msg);
   }
+
+  await prog.default()
 };