cache-busting query string in build for worker files

CHANGELOG.md

@@ -13,6 +13,7 @@
 ### Editor and UI
 
 - The IDE now works in Firefox: a synchronous XHR with a `responseType` hangs in Firefox when the response is 1MB or more, so the build worker hung forever on platforms with a big toolchain package (Game Boy, Atari 8-bit, Apple II, ...). The worker now fetches those packages as ArrayBuffers. A worker that dies no longer leaves the IDE spinning: the error is shown and the build stops.
+- Firefox no longer serves a stale build worker or toolchain package after an update: its hard reload (cmd+shift+r) doesn't revalidate requests made from a worker. The IDE now puts a build id in the worker URL, and the worker passes it on to every package and library it fetches.
 
 ## [4.0.0] - 2026-10-21
 

scripts/build.mjs

@@ -12,6 +12,9 @@
 import esbuild from 'esbuild';
 import mdPlugin from './md-loader.mjs';
 
+// identifies this build; the IDE puts it in the worker URL to defeat stale caches
+const define = { __BUILD_ID__: JSON.stringify(Date.now().toString(36)) };
+
 const configs = {
   worker: {
     entryPoints: ['src/worker/workermain.ts'],
@@ -54,6 +57,7 @@ for (const name of targets) {
   }
   const ctx = await esbuild.context({
     ...config,
+    define,
     plugins: [mdPlugin],
   });
   if (watch) {

src/ide/ui.ts

@@ -47,6 +47,7 @@ import { findListingLocation as findListingLocationPure } from "./search/listing
 import DOMPurify = require("dompurify");
 
 // external libs (TODO)
+declare var __BUILD_ID__: string; // defined by scripts/build.mjs
 declare var Tour;
 declare var $: JQueryStatic; // use browser jquery
 
@@ -132,7 +133,10 @@ export function getWorkerParams() {
 
 function newWorker(): Worker {
   // TODO: return new Worker("https://8bitworkshop.com.s3-website-us-east-1.amazonaws.com/dev/gen/worker/bundle.js");
-  return new Worker("./gen/worker/bundle.js");
+  // The build id in the query string makes Firefox refetch the bundle after a
+  // rebuild (hard reload doesn't cover workers); the worker reuses it for its
+  // own fetches via cacheBust().
+  return new Worker("./gen/worker/bundle.js" + (typeof __BUILD_ID__ != 'undefined' ? '?v=' + __BUILD_ID__ : ''));
 }
 
 const hasLocalStorage: boolean = function () {

src/worker/builder.ts

@@ -10,6 +10,16 @@ import { TOOLS } from "./workertools";
 const PSRC = "../../src/";
 export const PWORKER = PSRC + "worker/";
 
+/**
+ * Append the worker's own query string (the IDE's build id, see newWorker()
+ * in ide/ui.ts) to a URL the worker fetches. Firefox's hard reload does not
+ * revalidate requests made from a worker, so without this a stale bundle or
+ * toolchain package survives cmd+shift+r. Empty in node tests.
+ */
+export function cacheBust(url: string): string {
+  return url + ((typeof location != 'undefined' && location.search) || '');
+}
+
 export type FileData = string | Uint8Array;
 
 export type FileEntry = {
@@ -423,7 +433,7 @@ export function populateExtraFiles(step: BuildStep, fs, extrafiles, processFn?:
 export function fetchLibraryFile(platform: string, name: string): Uint8Array | null {
   var xhr = new XMLHttpRequest();
   xhr.responseType = 'arraybuffer';
-  xhr.open("GET", PWORKER + "lib/" + getBasePlatform(platform) + "/" + name, false);  // synchronous request
+  xhr.open("GET", cacheBust(PWORKER + "lib/" + getBasePlatform(platform) + "/" + name), false);  // synchronous request
   xhr.send(null);
   return xhr.response && xhr.status == 200 ? new Uint8Array(xhr.response) : null;
 }

src/worker/wasiutils.ts

@@ -1,7 +1,7 @@
 import JSZip from 'jszip';
 import { WASIRunner, WASIMemoryFilesystem } from "../common/wasi/wasishim";
 import { WorkerError } from "../common/workertypes";
-import { BuildStep, store } from "./builder";
+import { BuildStep, cacheBust, store } from "./builder";
 import { hasErrors, re_crlf } from "./listingutils";
 import { ensureWasiFilesystem, loadWASMBinary, makeBlob } from "./wasmutils";
 
@@ -10,7 +10,7 @@ export function loadBlobSync(path: string) {
     // arraybuffer, not blob: Firefox hangs on a synchronous XHR with
     // responseType='blob' for responses of 1MB or more (see wasmutils.makeBlob)
     xhr.responseType = 'arraybuffer';
-    xhr.open("GET", path, false);  // synchronous request
+    xhr.open("GET", cacheBust(path), false);  // synchronous request
     xhr.send(null);
     return makeBlob(xhr.response);
 }

src/worker/wasmutils.ts

@@ -2,7 +2,7 @@
 // WebAssembly module cache
 // for Emscripten-compiled functions
 
-import { BuildStep, PWORKER, endtime, starttime, putWorkFile, anyTargetChanged } from "./builder";
+import { BuildStep, PWORKER, cacheBust, endtime, starttime, putWorkFile, anyTargetChanged } from "./builder";
 
 /// <reference types="emscripten" />
 export interface EmscriptenModule {
@@ -151,12 +151,12 @@ export function getFilesystemSize(name: string): number {
 export function loadFilesystem(name: string) {
   var xhr = new XMLHttpRequest();
   xhr.responseType = 'arraybuffer';
-  xhr.open("GET", PWORKER + "fs/fs" + name + ".data", false);  // synchronous request
+  xhr.open("GET", cacheBust(PWORKER + "fs/fs" + name + ".data"), false);  // synchronous request
   xhr.send(null);
   fsBlob[name] = makeBlob(xhr.response);
   xhr = new XMLHttpRequest();
   xhr.responseType = 'json';
-  xhr.open("GET", PWORKER + "fs/fs" + name + ".js.metadata", false);  // synchronous request
+  xhr.open("GET", cacheBust(PWORKER + "fs/fs" + name + ".js.metadata"), false);  // synchronous request
   xhr.send(null);
   fsMeta[name] = xhr.response;
   console.log("Loaded " + name + " filesystem", fsMeta[name].files.length, 'files', fsBlob[name].size, 'bytes');
@@ -165,7 +165,7 @@ export function loadFilesystem(name: string) {
 var loaded = {};
 export function load(modulename: string, debug?: boolean) {
   if (!loaded[modulename]) {
-    importScripts(PWORKER + 'asmjs/' + modulename + (debug ? "." + debug + ".js" : ".js"));
+    importScripts(cacheBust(PWORKER + 'asmjs/' + modulename + (debug ? "." + debug + ".js" : ".js")));
     loaded[modulename] = 1;
   }
 }
@@ -173,7 +173,7 @@ export function loadWASMBinary(modulename: string) {
   if (!loaded[modulename]) {
     var xhr = new XMLHttpRequest();
     xhr.responseType = 'arraybuffer';
-    xhr.open("GET", PWORKER + "wasm/" + modulename + ".wasm", false);  // synchronous request
+    xhr.open("GET", cacheBust(PWORKER + "wasm/" + modulename + ".wasm"), false);  // synchronous request
     xhr.send(null);
     if (xhr.response) {
       wasmBlob[modulename] = new Uint8Array(xhr.response);
@@ -187,7 +187,7 @@ export function loadWASMBinary(modulename: string) {
 }
 export function loadWASM(modulename: string, debug?: boolean) {
   if (!loaded[modulename]) {
-    importScripts(PWORKER + "wasm/" + modulename + (debug ? "." + debug + ".js" : ".js"));
+    importScripts(cacheBust(PWORKER + "wasm/" + modulename + (debug ? "." + debug + ".js" : ".js")));
     loadWASMBinary(modulename);
   }
 }