fix(server): fall back to a passthrough when console.createTask is inert

packages/vinext/src/server/server-globals.ts

@@ -15,6 +15,12 @@ const PHASE_PRODUCTION_BUILD = "phase-production-build";
 
 type BrowserGlobalName = "window" | "document";
 
+type ConsoleTaskLike = { name: string; run: <T>(fn: () => T) => T };
+
+type ConsoleWithCreateTask = typeof console & {
+  createTask?: unknown;
+};
+
 function clearBrowserGlobal(name: BrowserGlobalName): void {
   const descriptor = Object.getOwnPropertyDescriptor(globalThis, name);
 
@@ -40,6 +46,30 @@ function clearBrowserGlobal(name: BrowserGlobalName): void {
   }
 }
 
+/**
+ * Fall back to a synchronous passthrough when `console.createTask` is inert.
+ *
+ * workerd's console exposes `createTask` but throws "not implemented" when it
+ * is called, and React's development builds call it at module initialization
+ * and during rendering (scheduler task tracing). The combination crashes every
+ * server environment on Workers, so probe the runtime implementation once and
+ * replace it with a passthrough when it cannot execute. A working
+ * implementation (Node's task tracer) is left untouched.
+ */
+function installCreateTaskFallback(): void {
+  const existing = (console as ConsoleWithCreateTask).createTask;
+  if (typeof existing !== "function") return;
+
+  try {
+    (existing as (name: string) => ConsoleTaskLike)("vinext:createTask-probe").run(() => {});
+  } catch {
+    (console as ConsoleWithCreateTask).createTask = (name: string): ConsoleTaskLike => ({
+      name,
+      run: (fn) => fn(),
+    });
+  }
+}
+
 export function installServerGlobals(): void {
   clearBrowserGlobal("window");
   clearBrowserGlobal("document");
@@ -55,6 +85,8 @@ export function installServerGlobals(): void {
     });
   }
 
+  installCreateTaskFallback();
+
   const nextPhaseDescriptor = Object.getOwnPropertyDescriptor(globalThis, "__VINEXT_NEXT_PHASE");
   if (!nextPhaseDescriptor || nextPhaseDescriptor.configurable) {
     Object.defineProperty(globalThis, "__VINEXT_NEXT_PHASE", {

tests/edge-globals.test.ts

@@ -10,7 +10,7 @@
  * that do `new AsyncLocalStorage()` without an import fail with
  *   ReferenceError: AsyncLocalStorage is not defined.
  */
-import { describe, expect, it } from "vite-plus/test";
+import { afterEach, describe, expect, it } from "vite-plus/test";
 import { AsyncLocalStorage as NodeAsyncLocalStorage } from "node:async_hooks";
 
 import { installServerGlobals } from "../packages/vinext/src/server/server-globals.js";
@@ -165,3 +165,60 @@ describe("edge runtime globals", () => {
     }
   });
 });
+
+type TaskLike = { name: string; run: <T>(fn: () => T) => T };
+
+describe("console.createTask fallback", () => {
+  const originalDescriptor = Object.getOwnPropertyDescriptor(console, "createTask");
+
+  afterEach(() => {
+    if (originalDescriptor) {
+      Object.defineProperty(console, "createTask", originalDescriptor);
+    }
+  });
+
+  it("replaces a createTask implementation that throws when called", () => {
+    // workerd exposes console.createTask but throws "not implemented" on call.
+    Object.defineProperty(console, "createTask", {
+      configurable: true,
+      writable: true,
+      value: () => {
+        throw new Error("not implemented");
+      },
+    });
+
+    installServerGlobals();
+
+    const createTask = (console as unknown as { createTask: (name: string) => TaskLike })
+      .createTask;
+    const task = createTask("render");
+    expect(task.name).toBe("render");
+    expect(task.run(() => 42)).toBe(42);
+  });
+
+  it("leaves a working createTask implementation untouched", () => {
+    const working = (name: string): TaskLike => ({ name, run: (fn) => fn() });
+    Object.defineProperty(console, "createTask", {
+      configurable: true,
+      writable: true,
+      value: working,
+    });
+
+    installServerGlobals();
+
+    expect((console as { createTask: unknown }).createTask).toBe(working);
+  });
+
+  it("does not add createTask when the runtime does not expose it", () => {
+    const consoleWithoutCreateTask = console as unknown as Record<string, unknown>;
+    const saved = consoleWithoutCreateTask["createTask"];
+    delete consoleWithoutCreateTask["createTask"];
+
+    try {
+      installServerGlobals();
+      expect("createTask" in (console as object)).toBe(false);
+    } finally {
+      consoleWithoutCreateTask["createTask"] = saved;
+    }
+  });
+});