Pipe

The pipe function combines multiple middleware into one. It takes an array of middleware and returns a new middleware that processes a request and context through each middleware in sequence.

Usage

Let's start with the following middlewares and handlers:

const middlewareStatus = (() => (request, context, runtime) => {
  return { status: 'OK' };
}) satisfies Get<[], UniversalMiddleware>;

const middlewareEarlyResponseError = (() => (request, context, runtime) => {
  if (context.status && context.status !== 'OK') {
    return new Response("Error", { status: 500 });
  }
}) satisfies Get<[], UniversalMiddleware<{ status?: string }>>;

const handler = (() => (request, context, runtime) => {
  return new Response(context.status ?? "OK");
}) satisfies Get<[], UniversalHandler<{ status?: string }>>;

You can pipe universal middlewares together, creating a new middleware that combines their behavior:

const newMiddleware = pipe(middlewareStatus(), middlewareEarlyResponseError())

You can also pipe universal middlewares and handlers together, creating a new handler that combines their behavior:

const newHandler = pipe(middlewareStatus(), middlewareEarlyResponseError(), handler())

You can also pipe middlewares or handlers that are adapter specific.

Any adapter specific middleware will act as if they were universal:

import { createMiddleware } from "@universal-middleware/hono";

const honoMiddlewareStatus = createMiddleware(middlewareStatus);

const newHandler = pipe(honoMiddlewareStatus(), middlewareEarlyResponseError(), handler())
//    ^ `newHandler` is a universal handler because `handler` is universal

Any adapter specific handler will keep their signature once returned:

import { createHandler } from "@universal-middleware/hono";

const honoHandler = createHandler(handler);

const newHonoHandler = pipe(middlewareStatus(), middlewareEarlyResponseError(), honoHandler())
//    ^ `newHonoHandler` is a hono handler because `honoHandler` is hono-specific
// It can directly be used by hono: app.get("/", newHonoHandler);

WARNING

This is only valid for middlewares and handlers generated thanks to universal-middleware