Use separate browser/node entrypoints instead of runtime environment detection

source/npm/qsharp/package.json

@@ -12,7 +12,11 @@
     "directory": "npm"
   },
   "exports": {
-    ".": "./dist/main.js",
+    ".": {
+      "browser": "./dist/browser.js",
+      "node": "./dist/node.js",
+      "default": "./dist/browser.js"
+    },
     "./compiler-worker": "./dist/compiler/worker.js",
     "./language-service-worker": "./dist/language-service/worker.js",
     "./debug-service-worker": "./dist/debug-service/worker.js",

source/npm/qsharp/src/browser.ts

@@ -0,0 +1,6 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+// Browser entrypoint. No Worker polyfill needed — browsers provide it natively.
+
+export * from "./main.js";

source/npm/qsharp/src/main.ts

@@ -1,7 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
-// This module is the single entry point for both browser and Node.js environments.
+// Shared implementation. Use the browser or node entrypoint instead of importing directly.
 
 import * as wasm from "../lib/web/qsc_wasm.js";
 import initWasm, {
@@ -32,6 +32,12 @@ import { log } from "./log.js";
 import { ProjectLoader } from "./project.js";
 import { createProxy } from "./workers/main.js";
 
+let workerType: "classic" | "module" = "classic";
+
+export function setWorkerType(type: "classic" | "module") {
+  workerType = type;
+}
+
 // Create once. A module is stateless and can be efficiently passed to WebWorkers.
 let wasmModule: WebAssembly.Module | null = null;
 let wasmModulePromise: Promise<void> | null = null;
@@ -126,7 +132,7 @@ export function getDebugServiceWorker(
   worker: string | Worker,
 ): IDebugServiceWorker {
   if (!wasmModule) throw "Wasm module must be loaded first";
-  return createProxy(worker, wasmModule, debugServiceProtocol);
+  return createProxy(worker, wasmModule, debugServiceProtocol, workerType);
 }
 
 export async function getCompiler(): Promise<ICompiler> {
@@ -139,7 +145,7 @@ export async function getCompiler(): Promise<ICompiler> {
 // messages, then the worker may be passed in and it will be initialized.
 export function getCompilerWorker(worker: string | Worker): ICompilerWorker {
   if (!wasmModule) throw "Wasm module must be loaded first";
-  return createProxy(worker, wasmModule, compilerProtocol);
+  return createProxy(worker, wasmModule, compilerProtocol, workerType);
 }
 
 export async function getLanguageService(
@@ -156,7 +162,7 @@ export function getLanguageServiceWorker(
   worker: string | Worker,
 ): ILanguageServiceWorker {
   if (!wasmModule) throw "Wasm module must be loaded first";
-  return createProxy(worker, wasmModule, languageServiceProtocol);
+  return createProxy(worker, wasmModule, languageServiceProtocol, workerType);
 }
 
 /// Extracts the target profile from a Q# source file's entry point.

source/npm/qsharp/src/node.ts

@@ -0,0 +1,14 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+// Node.js entrypoint. Polyfills the Worker global before loading the main module.
+
+import worker from "web-worker";
+import { setWorkerType } from "./main.js";
+
+if (typeof globalThis.Worker === "undefined") {
+  globalThis.Worker = worker;
+}
+setWorkerType("module");
+
+export * from "./main.js";

source/npm/qsharp/src/workers/main.ts

@@ -19,32 +19,14 @@ import type {
   ServiceState,
 } from "./types.js";
 
-export const isBrowser = typeof Worker !== "undefined";
-
-if (!isBrowser) {
-  // In CJS (esbuild bundle), require is available directly.
-  // In ESM (e.g. node --test), we use dynamic import.
-  if (typeof require === "function") {
-    // eslint-disable-next-line @typescript-eslint/no-require-imports
-    globalThis.Worker = require("web-worker");
-  } else {
-    // Dynamic import for ESM - this is lazy, Worker will be available
-    // by the time it's actually needed.
-    import("web-worker").then((mod) => {
-      globalThis.Worker = mod.default;
-    });
-  }
-  log.debug(
-    "Running in Node.js environment, using web-worker package for Worker support.",
-  );
-}
 /**
  * Creates and initializes a service in a web worker, and returns a proxy for the service
  * to be used from the main thread.
  *
  * @param workerArg The service web worker or the URL of the web worker script.
  * @param wasmModule The wasm module to initialize the service with
  * @param serviceProtocol An object that describes the service: its constructor, methods and events
+ * @param workerType The type of worker to create: "classic" for browsers, "module" for Node.js
  * @returns A proxy object that implements the service interface.
  *   This interface can now be used as if calling into the real service,
  *   and the calls will be proxied to the web worker.
@@ -56,11 +38,10 @@ export function createProxy<
   workerArg: string | Worker,
   wasmModule: WebAssembly.Module,
   serviceProtocol: ServiceProtocol<TService, TServiceEventMsg>,
+  workerType: "classic" | "module",
 ): TService & IServiceProxy {
   // Create or use the WebWorker
-  const useModuleWorker: WorkerOptions = isBrowser
-    ? { type: "classic" }
-    : { type: "module" };
+  const useModuleWorker: WorkerOptions = { type: workerType };
 
   const worker =
     typeof workerArg === "string"

source/npm/qsharp/test/basics.js

@@ -14,7 +14,7 @@ import {
   getDebugServiceWorker,
   loadWasmModule,
   utils,
-} from "../dist/main.js";
+} from "../dist/node.js";
 
 import { QscEventTarget } from "../dist/compiler/events.js";
 import { getAllKatas, getExerciseSources, getKata } from "../dist/katas.js";

source/npm/qsharp/test/circuits.js

@@ -15,7 +15,7 @@ import { afterEach, beforeEach, test } from "node:test";
 import { fileURLToPath } from "node:url";
 import prettier from "prettier";
 import { log } from "../dist/log.js";
-import { getCompiler, loadWasmModule } from "../dist/main.js";
+import { getCompiler, loadWasmModule } from "../dist/node.js";
 import { draw } from "../dist/ux/circuit-vis/index.js";
 
 // Load the wasm module before running any tests

source/npm/qsharp/test/diagnostics.js

@@ -13,7 +13,7 @@ import {
   getCompilerWorker,
   getProjectLoader,
   loadWasmModule,
-} from "../dist/main.js";
+} from "../dist/node.js";
 
 const distDir = new URL("../dist/", import.meta.url);
 const compilerWorkerPath = new URL("compiler/worker.js", distDir).href;

source/npm/qsharp/test/languageService.js

@@ -7,7 +7,7 @@ import assert from "node:assert/strict";
 import { readFileSync } from "node:fs";
 import { test } from "node:test";
 import { log } from "../dist/log.js";
-import { getLanguageService, loadWasmModule } from "../dist/main.js";
+import { getLanguageService, loadWasmModule } from "../dist/node.js";
 
 // Load the wasm module before running any tests
 const wasmPath = new URL("../lib/web/qsc_wasm_bg.wasm", import.meta.url);