ultrafetch
Modular utilities for enhancing fetch behavior. Bring Your Own Fetch implementation supports both node-fetch and unidici's fetch (globally available in node@18+).
withCache
The withCache function enhances fetch with RFC-7234 compliant cache behavior. The default cache is a simple in-memory Map, but custom caches are also supported.
import { withCache } from "ultrafetch";
const enhancedFetch = withCache(fetch);Any custom cache that adheres to a Map interface is valid.
import { withCache } from "ultrafetch";
class MyCache implements Map {
clear(): void;
delete(key: K): boolean;
get(key: K): V| undefined>;
has(key: K): boolean;
set(key: K, value: V): this;
readonly size: number;
}
const enhancedFetch = withCache(fetch, { cache: new MyCache() });Custom caches can also use the AsyncMap interface, which is the same as a standard Map but each method is async.
import type { AsyncMap } from "ultrafetch";
import { withCache } from "ultrafetch";
class MyAsyncCache implements AsyncMap {
clear(): Promise<void>;
delete(key: K): Promise<boolean>;
get(key: K): Promise<V | undefined>;
has(key: K): Promise<boolean>;
set(key: K, value: V): Promise<this>;
readonly size: number;
}
const enhancedFetch = withCache(fetch, { cache: new MyAsyncCache() });isCached
The isCached export can be used to determine if a given Response was returned from the cache or not.
import { withCache, isCached } from "ultrafetch";
const enhancedFetch = withCache(fetch);
const responseA = await enhancedFetch('https://example.com');
isCached(responseA) // false
const responseB = await enhancedFetch('https://example.com');
isCached(responseB) // true