@remix-run/router 1.23.3: createMemoryHistory, createRouter, matchRoutes

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify pkg:npm/%40remix-run/router@1.23.3
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40remix-run/router@1.23.3
Demonstrate these symbols/APIs:
  - createMemoryHistory
  - createRouter
  - matchRoutes

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:276e2f3aaed34e356e97ce964ca77748b9f2a69c4ce246c0fe080c92735c48f1","contract":["matchRoutes matches url pathname against route configuration and extracts params","createMemoryHistory creates in-memory history with navigation stack and location tracking","createRouter initializes routing state and resolves route loaders","createRouter navigate transitions to dynamic routes and loads matching route data","createRouter dispose cleans up listeners and tears down router instance"],"goal":"verify pkg:npm/%40remix-run/router@1.23.3","kind":"HOW","packages":["pkg:npm/%40remix-run/router@1.23.3"],"schemaVersion":1,"symbols":["createMemoryHistory","createRouter","matchRoutes"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/%40remix-run/router@1.23.3"],"schemaVersion":1,"subject":"pkg:npm/%40remix-run/router@1.23.3","symbols":["createMemoryHistory","createRouter","matchRoutes"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-remix-router",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-remix-router",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "@remix-run/router": "1.23.3"
      }
    },
    "node_modules/@remix-run/router": {
      "version": "1.23.3",
      "resolved": "https://registry.npmjs.org/@remix-run/router/-/router-1.23.3.tgz",
      "integrity": "sha512-4An71tdz9X8+3sI4Qqqd2LWd9vS39J7sqd9EU4Scw7TJE/qB10Flv/UuqbPVgfQV9XoK8Np6jNquZitnZq5i+Q==",
      "license": "MIT",
      "engines": {
        "node": ">=14.0.0"
      }
    }
  }
}

{
  "name": "sample-remix-router",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification sample for @remix-run/router",
  "type": "module",
  "main": "src/index.js",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "@remix-run/router": "1.23.3"
  },
  "license": "MIT-0"
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/%40remix-run/router@1.23.3",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40remix-run/router@1.23.3"
  ],
  "symbols": [
    "createMemoryHistory",
    "createRouter",
    "matchRoutes"
  ]
}

import { createRouter, createMemoryHistory, matchRoutes } from '@remix-run/router';

/**
 * Creates and initializes a memory router with the given route configuration.
 * @param {Array} routes - Route definitions.
 * @param {Object} [options={}] - Router options including initialEntries.
 * @returns {Promise<{ router: Object, history: Object, cleanup: Function }>} Initialized router and cleanup function.
 */
export async function setupMemoryRouter(routes, options = {}) {
  const { initialEntries = ['/'] } = options;
  const history = createMemoryHistory({ initialEntries });
  const router = createRouter({
    routes,
    history,
  });

  await new Promise((resolve) => {
    const unsubscribe = router.subscribe((state) => {
      if (state.initialized) {
        unsubscribe();
        resolve(state);
      }
    });
    router.initialize();
  });

  return {
    router,
    history,
    cleanup: () => router.dispose(),
  };
}

/**
 * Matches a pathname against route definitions.
 * @param {Array} routes - Route definitions.
 * @param {string} pathname - Path to match.
 * @returns {Array|null} Matching route branches with params.
 */
export function findMatchingRoutes(routes, pathname) {
  return matchRoutes(routes, pathname);
}

/**
 * Creates an in-memory history object.
 * @param {Array<string>} [initialEntries=['/']] - Initial history entries.
 * @returns {Object} Memory history instance.
 */
export function initMemoryHistory(initialEntries = ['/']) {
  return createMemoryHistory({ initialEntries });
}

export { createRouter, createMemoryHistory, matchRoutes };

import assert from 'node:assert';
import {
  createRouter,
  createMemoryHistory,
  matchRoutes,
  setupMemoryRouter,
  findMatchingRoutes,
  initMemoryHistory,
} from '../src/index.js';

// 1. matchRoutes matches url pathname against route configuration and extracts params
const routes = [
  {
    path: '/',
    id: 'root',
    loader: async () => ({ title: 'Home' }),
    children: [
      {
        path: 'items/:itemId',
        id: 'item-detail',
        loader: async ({ params }) => ({ itemId: params.itemId, loaded: true }),
      },
      {
        path: 'settings',
        id: 'settings',
        loader: async () => ({ section: 'general' }),
      },
    ],
  },
];

const matches = findMatchingRoutes(routes, '/items/42');
assert.ok(Array.isArray(matches), 'matchRoutes returns array of matches');
assert.strictEqual(matches.length, 2, 'matches root and child route');
assert.strictEqual(matches[0].route.id, 'root');
assert.strictEqual(matches[1].route.id, 'item-detail');
assert.strictEqual(matches[1].params.itemId, '42', 'extracts itemId param correctly');

const nonMatching = findMatchingRoutes(routes, '/non-existent-route');
assert.strictEqual(nonMatching, null, 'returns null for unmatched paths');

// Direct symbol verification
assert.strictEqual(typeof matchRoutes, 'function');
assert.strictEqual(typeof createMemoryHistory, 'function');
assert.strictEqual(typeof createRouter, 'function');

// 2. createMemoryHistory creates in-memory history with navigation stack and location tracking
const history = initMemoryHistory(['/first', '/second']);
assert.strictEqual(history.location.pathname, '/second', 'current location is last entry');
assert.strictEqual(history.index, 1, 'history index is 1');
history.push('/third');
assert.strictEqual(history.location.pathname, '/third', 'location updates after push');
assert.strictEqual(history.index, 2, 'history index increments');
history.go(-1);
assert.strictEqual(history.location.pathname, '/second', 'history navigation back works');

// 3. createRouter initializes routing state and resolves route loaders
const { router, cleanup } = await setupMemoryRouter(routes, { initialEntries: ['/'] });
assert.strictEqual(router.state.initialized, true, 'router reports initialized true');
assert.strictEqual(router.state.location.pathname, '/', 'initial location is root');
assert.deepStrictEqual(router.state.loaderData.root, { title: 'Home' }, 'root loader data resolved');

// 4. createRouter navigate transitions to dynamic routes and loads matching route data
await router.navigate('/items/99');
assert.strictEqual(router.state.location.pathname, '/items/99', 'location updated after navigation');
assert.deepStrictEqual(
  router.state.loaderData['item-detail'],
  { itemId: '99', loaded: true },
  'dynamic route loader executed and resolved'
);

await router.navigate('/settings');
assert.strictEqual(router.state.location.pathname, '/settings', 'navigated to settings');
assert.deepStrictEqual(
  router.state.loaderData.settings,
  { section: 'general' },
  'settings loader executed'
);

// 5. createRouter dispose cleans up listeners and tears down router instance
cleanup();
assert.ok(true, 'router disposed successfully');

console.log('Contract tests passed successfully.');