V4

[MattCCC]

Changelog

New Features

• React useFetcher(url, config) Hook
  Introduced a new React hook for data fetching with built-in caching, loading states, and revalidation. You can import { useFetcher } from 'fetchff/react';
  Check the new React Integration section in the documentationf or more infromation.

• Stale-While-Revalidate (SWR) Support
  Added staleTime configuration for serving stale data while revalidating in the background.

• Custom Cache Keys and Infinite Cache
  Added support for custom cache key functions and possibility to cache infinitely for permanent caching scenarios.

• Added refetchOnFocus setting
  Added support for refetchOnFocus (boolean) feature that automatically refetches data when the browser tab becomes visible/focused.

• New refetchOnReconnect setting
  Enhance revalidation options by adding refetchOnReconnect (boolean) and updating related logic

• Added onRetry(response, attempt) interceptor
  Implemented onRetry configuration to add interceptor based before each retry attempt.

• Added onAbort(response) interceptor
  Implemented onAbort configuration to add interceptor based before each abort attempt.

• Added cacheErrors setting
  Implemented cacheErrors (boolean) configuration to cache error responses for improved error handling.

• Add keepPreviousData setting
  With keepPreviousData: true the last query’s data remains visible until the new one finishes loading.

• Adaptive timeouts based on connection speed
  implement adaptive timeouts based on connection speed for improved user experience

• Added isCancelled property to error objects
  This boolean lets us to quickly preview if request has been aborted.

• Automatically set the Content-Type header based on th body type (beyond just JSON)
  Updated Content-Type handling in fetchff to automatically set based on request body type and enhanced isJSONSerializable checks.

• ** Add select(data) => modifiedData setting**
  Add select(data) => modifiedData setting to transform response data for better performance.

Breaking changes

• The fetcher setting now accepts a function only
  Previously it was an object with create and request. To simplify this, it's enough to pass fetcher function now. No instance creation is needed anymore.

• Removed old, unused CanceledError detection for cancelled requests
  Use AbortError or TimeoutError instead.

• Only some of request headers are considered in auto-key generation
  This is to improve cache hit rates. Carefully curated list is available in the readme file.

• flattenData setting can flatten when there are more keys beyond just data available
  This will flatten up to the last data in an object available, recursively.

• Single object typings over 4 generics
  The typings have been improved for performance and clarity reasons. Usage: {response: ResponseData, body: RequestBody, params: QueryParams, urlPathParams: UrlPathParams}. Check documentation for more examples

Module and Build Improvements

• Exports Field in package.json
  Defined module entry points for Node.js, browser, and React environments to improve compatibility.

• Centralized Build Configuration
  Simplified build setup with a shared tsup.config.ts file.

Request and Cache Enhancements

• Improved Cache Mutation and Busting
  Enhanced mutate() with revalidation and subscriber notifications.
  getCachedResponse now supports full RequestConfig for cache busting.

• Private Cache Implementation
  Internal _cache map is now fully encapsulated for better control and safety.

• Inflight Manager Refactoring
  Replaced queue-manager with inflight-manager for clearer request deduplication and timeout handling.

• shouldRetry can return null
  shouldRetry can return null so to fallback to retryOn status codes.

• Interceptors running in right order
  Interceptors are now running in right order - FIFO for all, LIFO for On Response + added a section in documentation about it.

• Removed properties from cache key auto-generation
  The following behavior controlled cache key properties are removed: cache, mode, redirect, referrer, integrity as they should not impact the key generation.

Testing

• Added tests for React hook, concurrent request behavior, cache consistency, and memory cleanup.

Bug Fixes

• Base URL Handling
  Ensured baseURL defaults to an empty string when undefined.

• Memory Management
  Improved cleanup of timers and subscriptions to prevent leaks.

• Cancellable requests abortion
  Returning an aborted controller would cause any new fetch to fail instantly.

• Previous Cancellable requests were blocked by dedupeTime
  Deduplication logic should not block cancellable requests.

• Absolute URLs in API Handler
  Apply endpoint config to absolute URLs defined if defined.

Developer Experience

• Exposed subscribe(cacheKey, callback) function
  Added subscribe(cacheKey, callback) function for global real-time cache updates and data synchronization (tree-shakeable).

• Exposed abortRequest(cacheKey, error) function
  Added abortRequest(cacheKey, error) function for global request aborting (tree-shakeable).

• Exposed mutate(key, newData, settings) function
  Added mutate(key, newData, {fetch: boolean}) function for global request mutations (tree-shakeable).

• Exposed setDefaultConfig(customConfig) function
  Added setDefaultConfig(customConfig) function for default config overwrites (tree-shakeable).

• Exposed isSlowConnection() function
  Added isSlowConnection() function to detect slow connections in browsers (tree-shakeable).

• Exposed getCache(key) function
  Added getCache(key) function for directly retrieving cached data without triggering network requests (tree-shakeable).

• Exposed setCache(key, response, ttl, staleTime) function
  Added setCache(key, response, ttl, staleTime) function for low-level cache data management and direct cache entry creation (tree-shakeable).

• Exposed deleteCache(key) function
  Added deleteCache(key) function for selective cache invalidation and cleanup operations (tree-shakeable).

• Exposed revalidate(key, isStaleRevalidation) function
  Added revalidate(key, isStaleRevalidation) function for manual cache revalidation and fresh data fetching (tree-shakeable).

• Exposed revalidateAll(type, isStaleRevalidation) function
  Added revalidateAll(type, isStaleRevalidation) function for bulk revalidation of focus or online event-triggered cache entries (tree-shakeable).

• Exposed removeRevalidators(type) function
  Added removeRevalidators(type) function for cleanup of revalidation event listeners and memory leak prevention (tree-shakeable).

• Better Type Safety
  Improved TypeScript definitions and type clarity throughout codebase

• Code Organization
  Modularized code structure for better maintainability

[github-actions]

size-limit report 📦

Path	Size
dist/browser/index.mjs	5.28 KB (+34.11% 🔺)
dist/browser/index.global.js	5.44 KB (+32.54% 🔺)
dist/node/index.js	5.35 KB (+33.51% 🔺)
dist/react/index.mjs	8.32 KB (+100% 🔺)
dist/react/index.js	9.03 KB (+100% 🔺)

[devdgna]

+1