Response API

Status, headers, bodies, redirects, files, cookies, and streaming with ExpressResponse.

Return JSON with status and headers

import { ExpressRoute } from '@astro-utils/express-endpoints';

const router = new ExpressRoute();
export const GET = router.route((_req, res) => {
    res.status(200);
    res.set('Cache-Control', 'no-store');
    res.json({ status: 'ready', checkedAt: new Date().toISOString() });
});

A GET to /api/status returns JSON with an explicit status and cache policy. Set headers before sending the body; json() finishes the response.

ExpressResponse is a writable stream. Set status and headers before the first write() or end() call.

Save a preference and redirect

import { ExpressRoute } from '@astro-utils/express-endpoints';

const router = new ExpressRoute();
export const POST = router.route((_req, res) => {
    res.cookie('theme', 'dark', { httpOnly: true, sameSite: 'lax', path: '/', maxAge: 86400000 }); // maxAge in milliseconds
    res.redirect('/', 303);
});

The cookie stores a display preference, not an authentication credential. Use secure cookies when serving over HTTPS. A 303 redirects the browser to a GET after the POST.

Stream a text response

import { ExpressRoute } from '@astro-utils/express-endpoints';

const router = new ExpressRoute();
export const GET = router.route((_req, res) => {
    res.type('text/plain');
    res.write('Report started\n');
    res.end('Report complete\n');
});

Set headers before the first write, and always end the response. For a file already on disk, use sendFile or attachment instead.

Finish a response

Method	Behavior
`status(code)`	Sets `statusCode`.
`sendStatus(code)`	Sends the standard status text.
`send(body)`	Sends bytes, text, or JSON-compatible data.
`json(value)`	Sends JSON.
`html(value)`	Sends HTML.
`end(body?)`	Ends the response.
`write(chunk, encoding?)`	Starts or continues a streamed response.
`redirect(url, status?)`	Redirects with status 302 by default.
`sendFile(path)`	Streams a file and infers its content type.
`attachment(path, name?)`	Streams a file as a download.

Headers and cookies

Method	Behavior
`set()` / `header()`	Sets one header or a header map.
`get()` / `getHeader()`	Reads a header.
`getHeaders()` / `getHeaderNames()`	Lists response headers.
`hasHeader()` / `removeHeader()`	Checks or removes a header.
`append()` / `appendHeader()`	Appends a header value.
`type(value)`	Sets a MIME content type.
`writeHead(code, headers?)`	Sets status and headers, then starts the response.
`cookie(name, value, options?)`	Appends a `Set-Cookie` header. Object values use JSON cookie encoding.
`clearCookie(name, options?)`	Expires a cookie.
`cacheControl({ minuets, days, months })`	Sets `max-age`. The public minute option is spelled `minuets`.

headersSent becomes true after the response starts. Header changes and duplicate response endings then throw ExpressError.