snapshot of https://github.com/TanStack/query.git (main, 2026-09-16; blobs > 131072B omitted)

packages/query-core/src/environmentManager.ts

@@ -0,0 +1,37 @@
+import { isServer as defaultIsServer } from './utils'
+
+export type IsServerValue = () => boolean
+
+let isServerFn: IsServerValue = () => defaultIsServer
+
+/**
+ * Returns whether the current runtime should be treated as a server environment.
+ */
+export const isServer = (): boolean => isServerFn()
+
+/**
+ * Manages how TanStack Query detects whether the current runtime should be treated as
+ * server-side, which disables scheduling refetch timers and changes the default `retry` count
+ * and `gcTime`. By default, the detection treats a missing `window` (or the presence of a
+ * `Deno` global) as server.
+ *
+ * Override this for runtimes where that default detection would give the wrong answer — for
+ * example, a Service Worker, where `window` is undefined even though the environment should
+ * behave like a client.
+ *
+ * @example
+ * ```ts
+ * import { environmentManager } from '@tanstack/query-core'
+ *
+ * environmentManager.setIsServer(() => false)
+ * ```
+ */
+export const environmentManager = {
+  isServer,
+  /**
+   * Overrides the server check globally.
+   */
+  setIsServer(isServerValue: IsServerValue): void {
+    isServerFn = isServerValue
+  },
+}