cache-control-parser

cache-control-parser

A humble cache-control parser.

Features

• Fault-tolerant
• Case-insensitive
• No dependencies
• Built-in TypeScript support
• Thoroughly tested

✨ New: you can now stringify cache control objects

Getting Started

Installation

To use cache-control-parser in your project, run:

npm install cache-control-parser

Usage

Example - parse a string of cache control directives into an object:

import { parse } from "cache-control-parser";

const directives = parse(
  "public, max-age=300, no-transform"
);

console.log(directives);

Output:

{
  "public": true,
  "max-age": 300,
  "no-transform": true
}

Example - destructuring the cache control object:

import { parse } from "cache-control-parser";

const directives = parse(
  "max-age=300, s-maxage=0"
);

const { "max-age": maxAge, "s-maxage": sMaxAge } = directives;

Example - retrieve the shared proxy cache TTL:

import { parse } from "cache-control-parser";

const cacheControl = parse(
  "max-age=300, s-maxage=0"
);

const ttl = cacheControl["s-maxage"] ?? cacheControl["max-age"];

console.log("ttl:", ttl);

Output:

ttl: 0

Example - stringify a cache control object:

import { stringify } from "cache-control-parser";

const cacheControl = stringify({
  "max-age": 300,
  "s-maxage": 3600,
  "public": true
});

console.log(cacheControl);

Output:

max-age=300, s-maxage=3600, public

Example - Next.js API route response header:

import { stringify } from "cache-control-parser";
import type { NextApiRequest, NextApiResponse } from "next";

export default (req: NextApiRequest, res: NextApiResponse) => {
  res.setHeader(
    "Cache-Control",
    stringify({
      "max-age": 300,
    })
  );

  res.send("Hello world");
};

Supported cache-control directives:

{
  "max-age"?: number;
  "s-maxage"?: number;
  "stale-while-revalidate"?: number;
  "stale-if-error"?: number;
  "public"?: boolean;
  "private"?: boolean;
  "no-store"?: boolean;
  "no-cache"?: boolean;
  "must-revalidate"?: boolean;
  "proxy-revalidate"?: boolean;
  "immutable"?: boolean;
  "no-transform"?: boolean;
}

TypeScript

Type definitions are included in this library and exposed via:

import type { CacheControl } from "cache-control-parser";

Built with

• node.js - Cross-platform JavaScript run-time environment for executing JavaScript code server-side.
• TypeScript - Typed superset of JavaScript that compiles to plain JavaScript.
• Jest - Delightful JavaScript Testing.

Contributing

When contributing to this project, please first discuss the change you wish to make via issue, email, or any other method with the owners of this repository before making a change.

Update the README.md with details of changes to the library.

Execute yarn test and update the tests if needed.

Testing

Run the full test suite:

yarn test

Run tests in watch mode:

yarn test:watch

Authors

• Etienne Martin - Initial work - etiennemartin.ca

License

This project is licensed under the MIT License - see the LICENSE file for details.