/** * The `GlobalValue` module ensures that a single instance of a value is created globally, * even when modules are imported multiple times (e.g., due to mixing CommonJS and ESM builds) * or during hot-reloading in development environments like Next.js or Remix. * * It achieves this by using a versioned global store, identified by a unique `Symbol` tied to * the current version of the `effect` library. The store holds values that are keyed by an identifier, * allowing the reuse of previously computed instances across imports or reloads. * * This pattern is particularly useful in scenarios where frequent reloading can cause services or * single-instance objects to be recreated unnecessarily, such as in development environments with hot-reloading. * * @since 2.0.0 */ import * as version from "./internal/version.js"; const globalStoreId = `effect/GlobalValue/globalStoreId/${/*#__PURE__*/version.getCurrentVersion()}`; let globalStore; /** * Retrieves or computes a global value associated with the given `id`. If the value for this `id` * has already been computed, it will be returned from the global store. If it does not exist yet, * the provided `compute` function will be executed to compute the value, store it, and then return it. * * This ensures that even in cases where the module is imported multiple times (e.g., in mixed environments * like CommonJS and ESM, or during hot-reloading in development), the value is computed only once and reused * thereafter. * * @example * ```ts * import { globalValue } from "effect/GlobalValue" * * // This cache will persist as long as the module is running, * // even if reloaded or imported elsewhere * const myCache = globalValue( * Symbol.for("myCache"), * () => new WeakMap() * ) * ``` * * @since 2.0.0 */ export const globalValue = (id, compute) => { if (!globalStore) { // @ts-expect-error globalThis[globalStoreId] ??= new Map(); // @ts-expect-error globalStore = globalThis[globalStoreId]; } if (!globalStore.has(id)) { globalStore.set(id, compute()); } return globalStore.get(id); }; //# sourceMappingURL=GlobalValue.js.map