route-sort

A tiny (200B) utility to sort route patterns by specificity.

This module is available in three formats:

• ES Module: dist/rsort.mjs
• CommonJS: dist/rsort.js
• UMD: dist/rsort.min.js

Install

$ npm install --save route-sort

Usage

import rsort from 'route-sort';

// We have multiple Author-based routes
// Note: These are currently an unsorted mess
const routes = ['/authors', '/authors/*', '/authors/:username/posts', '/authors/:username'];

const output = rsort(routes);

// Now, our routes are sorted correctly!
console.log(routes);
//=> [ '/authors', '/authors/:username', '/authors/:username/posts', '/authors/*' ]

// The original input was mutated, but it's also returned
console.log(routes === output);
//=> true

API

rsort(patterns)

Returns: Array<String>

Returns the same patterns you provide, sorted by specificity.

Important: Your original array is mutated!

patterns

Type: Array<String>

A list of route pattern strings.

Route Patterns

The supported route pattern types are:

• static – /users
• named parameters – /users/:id
• nested parameters – /users/:id/books/:title
• optional parameters – /users/:id?/books/:title?
• suffixed parameters – /movies/:title.mp4, /movies/:title.(mp4|mov)
• wildcards – /users/*

Specificity

While this working definition may not apply completely across the board, route-sort is meant to sort Express-like routing patterns in a safe manner, such that a serial traversal of the sorted array will always give you the most specific match.

You may use regexparam to convert the patterns into RegExp instances, and then use those to test an incoming URL against the patterns. We'll do that in the example below:

import rsort from 'route-sort';
import toRegExp from 'regexparam';

// We have multiple Author-based routes
// Note: These are currently an unsorted mess
const routes = ['/authors', '/authors/*', '/authors/:username/posts', '/authors/:username'];

rsort(routes);
// Now, our routes are sorted correctly!
//=> [ '/authors', '/authors/:username', '/authors/:username/posts', '/authors/*' ]

// Let's make an inefficent DEMO function to:
// 1) loop thru the `routes` array
// 2) convert each pattern to a RegExp (repetitive)
// 3) test the RegExp to see if we had a match
function find(path) {
  for (let i=0; i < routes.length; i++) {
    let { pattern } = toRegExp(routes[i]);
    if (pattern.test(path)) return routes[i];
  }
  return false; // no match
}

find('/authors'); //=> "/authors"
find('/authors/lukeed'); //=> "/authors/:username"
find('/authors/foo/bar/baz'); //=> "/authors/*"
find('/authors/lukeed/posts'); //=> "/authors/:username/posts"
find('/hello/moto'); //=> false

// Sorting was important here, but otherwise our
// original `routes` list would have matched "/authors/*"
// against every path except `/hello/moto` and `/authors`.

// Cya!

Related

• regexparam – convert route patterns to RegExp instances
• route-manifest – runtime parser of the Route Manifest format
• webpack-route-manifest – generate a Route Manifest file for your webpack build

License

MIT © Luke Edwards