etag-middleware

HTTP ETag middleware.

Middleware

For a definition of Universal HTTP middleware, see the http-middleware project.

Usage

From the response, calculate the ETag and add it to the ETag header.

import { etag } from "https://deno.land/x/etag_middleware@$VERSION/mod.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";

const middleware = etag();
const response = await middleware(
  new Request("http://localhost"),
  (request) => new Response("ok"),
);

assertEquals(response.headers.get("etag"), `"<hex:SHA-1:body>"`);

yield:

ETag: W/"<hex:SHA-1:body>"

The Default ETag is a hexadecimal representation of the sha-1 digest of the Response body.

This is a weak ETag.

Effects

Middleware will effect following:

HTTP Headers
- ETag

Conditions

Middleware will execute only if the following conditions are met:

Response body is successful(2xx) status code
Response body exists
Response body is readable
ETag header does not exist in response

API

All APIs can be found in the deno doc.

License

Released under the MIT license