file-routing-expressjs
Version:
A dependency-free, flexible, system-based file routing for Express.
66 lines (63 loc) • 2.05 kB
TypeScript
import { Request, Response, RequestHandler } from 'express';
import { MapIndex } from './common.js';
/**
* Plugin definition for extending the routing lifecycle.
*
* A plugin can:
* - wrap route handlers (via `wrap`)
* - hook into the request lifecycle (`onRequest`, `onResponse`, `onError`)
*
* Execution model:
* - `wrap` transforms the final handler (composition phase)
* - `onRequest` runs before middleware/handler (can control flow via `next`)
* - `onResponse` runs after successful handler execution
* - `onError` runs when an error is thrown in the pipeline
*
* Notes:
* - All hooks support async execution
* - `onRequest` must call `next()` to continue the pipeline
* - `wrap` should return a new RequestHandler without mutating the original
*/
type PluginContext<Config = any, State = Record<MapIndex, any>> = {
req: Request;
res: Response;
config?: Config;
state: State;
};
type Plugin<Config = any, State = Record<MapIndex, any>> = {
name: string;
wrap?: (handler: RequestHandler, config?: Config) => RequestHandler;
onRequest?: (ctx: PluginContext<Config, State>, next: () => Promise<void>) => Promise<void>;
onResponse?: (ctx: PluginContext<Config, State>) => Promise<void>;
onError?: (err: unknown, ctx: PluginContext<Config, State>) => Promise<void>;
validateConfig?: (config: Config) => void;
};
type CacheConfig = {
ttl?: number;
max?: number;
};
type CacheEntry = {
expires: number;
status: number;
body: any;
};
type CircutBreakerConfig = {
threshold: number;
cooldown: number;
considerError?: (err: unknown) => boolean;
};
type CircuteBreakerEntryState = {
failures: number;
openUntil: number;
halfOpen: boolean;
inFlight: boolean;
};
type TimeoutConfig = {
ms: number;
};
type RetryConfig = {
attempts: number;
delay?: number;
shouldRetry?: (err: any) => boolean;
};
export type { CacheConfig, CacheEntry, CircutBreakerConfig, CircuteBreakerEntryState, Plugin, PluginContext, RetryConfig, TimeoutConfig };