fresh

What is fresh?

The 'fresh' npm package is a HTTP response freshness testing library. It is used to determine whether the response is still 'fresh' in the context of HTTP caching. It checks the request and response headers to decide if the response should be re-used or if a new one needs to be generated.

What are fresh's main functionalities?

Freshness Checking

This feature allows you to check if the HTTP response is still fresh by comparing the request and response headers. If the function returns true, the response is considered fresh.

const fresh = require('fresh');

const reqHeaders = { 'if-none-match': 'some-etag' };
const resHeaders = { 'etag': 'some-etag' };

const isFresh = fresh(reqHeaders, resHeaders);
console.log(isFresh); // true or false

Other packages similar to fresh

etag

The 'etag' package is used to generate HTTP ETags, which are typically used in HTTP headers to determine change in content at a given URL. While 'fresh' is used to check the freshness of responses, 'etag' helps in generating the identifiers that 'fresh' would use for its comparisons.

cache-control

The 'cache-control' package is used for parsing and formatting HTTP 'Cache-Control' headers. Unlike 'fresh', which checks for response freshness, 'cache-control' is more focused on providing utilities for working with the 'Cache-Control' header directly.

README

node-fresh

HTTP response freshness testing

fresh(req, res)

Check freshness of req and res headers.

When the cache is "fresh" true is returned, otherwise false is returned to indicate that the cache is now stale.

Example:

var req = { 'if-none-match': 'tobi' };
var res = { 'etag': 'luna' };
fresh(req, res);
// => false

var req = { 'if-none-match': 'tobi' };
var res = { 'etag': 'tobi' };
fresh(req, res);
// => true

Installation

$ npm install fresh