Fix between benchmark network requests for Dart-flute's JS Module. In that process I also had to change how 8bitbench loads the rom it's going to use.

8bitbench/benchmark.js

@@ -1,4 +1,5 @@
 // Copyright 2025 the V8 project authors. All rights reserved.
+// Copyright 2025 Apple Inc. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -34,6 +35,16 @@ function dumpFrame(vec) {
 
 class Benchmark {
   isInstantiated = false;
+  romBinary;
+
+  async init() {
+    if (isInBrowser) {
+      let response = await fetch(romBinary);
+      this.romBinary = new Int8Array(await response.arrayBuffer());
+    } else {
+      this.romBinary = new Int8Array(read(romBinary, "binary"));
+    }
+  }
 
   async runIteration() {
     if (!this.isInstantiated) {
@@ -41,7 +52,7 @@ class Benchmark {
       this.isInstantiated = true;
     }
 
-    wasm_bindgen.loadRom(Module.romBinary);
+    wasm_bindgen.loadRom(this.romBinary);
 
     const frameCount = 2 * 60;
     for (let i = 0; i < frameCount; ++i) {

Dart/benchmark.js

@@ -266,19 +266,14 @@ class Benchmark {
     // is a map from module variable name (which will hold the resulting module
     // namespace object) to relative module URL, which is resolved in the
     // `preRunnerCode`, similar to this code here.
-    if (isInBrowser) {
-      // In browsers, relative imports don't work since we are not in a module.
-      // (`import.meta.url` is not defined.)
-      const pathname = location.pathname.match(/^(.*\/)(?:[^.]+(?:\.(?:[^\/]+))+)?$/)[1];
-      this.dart2wasmJsModule = await import(location.origin + pathname + "./Dart/build/flute.dart2wasm.mjs");
-    } else {
+
+    try {
+      this.dart2wasmJsModule = await import(jsModule);
+    } catch {
       // In shells, relative imports require different paths, so try with and
       // without the "./" prefix (e.g., JSC requires it).
-      try {
-        this.dart2wasmJsModule = await import("Dart/build/flute.dart2wasm.mjs");
-      } catch {
-        this.dart2wasmJsModule = await import("./Dart/build/flute.dart2wasm.mjs");
-      }
+      if (!isInBrowser)
+        this.dart2wasmJsModule = await import(jsModule.slice("./".length))
     }
   }
 

JetStreamDriver.js

@@ -1228,8 +1228,12 @@ class WasmEMCCBenchmark extends AsyncBenchmark {
                 }
             `;
 
-        for (let [ preloadKey, blobURLOrPath ] of this.preloads)
-            str += `await getBinary("${preloadKey}", "${blobURLOrPath}");\n`
+        for (let [ preloadKey, blobURLOrPath ] of this.preloads) {
+            if (preloadKey == "wasmBinary") {
+                str += `await getBinary("${preloadKey}", "${blobURLOrPath}");\n`
+                break;
+            }
+        }
 
         str += super.runnerCode;
 
@@ -2078,7 +2082,8 @@ let BENCHMARKS = [
             "./Dart/benchmark.js",
         ],
         preload: {
-            wasmBinary: "./Dart/build/flute.dart2wasm.wasm"
+            jsModule: "./Dart/build/flute.dart2wasm.mjs",
+            wasmBinary: "./Dart/build/flute.dart2wasm.wasm",
         },
         iterations: 15,
         worstCaseCount: 2,