fix: disable hot reloading if in a WebWorker (#181)

Author: siefkenj

packages/plugin-react/src/fast-refresh.ts

@@ -31,10 +31,11 @@ window.__vite_plugin_react_preamble_installed__ = true
 const header = `
 import RefreshRuntime from "${runtimePublicPath}";
 
+const inWebWorker = typeof WorkerGlobalScope !== 'undefined' && self instanceof WorkerGlobalScope;
 let prevRefreshReg;
 let prevRefreshSig;
 
-if (import.meta.hot) {
+if (import.meta.hot && !inWebWorker) {
   if (!window.__vite_plugin_react_preamble_installed__) {
     throw new Error(
       "@vitejs/plugin-react can't detect preamble. Something is wrong. " +
@@ -51,7 +52,7 @@ if (import.meta.hot) {
 }`.replace(/\n+/g, '')
 
 const footer = `
-if (import.meta.hot) {
+if (import.meta.hot && !inWebWorker) {
   window.$RefreshReg$ = prevRefreshReg;
   window.$RefreshSig$ = prevRefreshSig;