real-require 1.0.0: realImport

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 real-require.realImport in pkg:npm/real-require@1.0.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/real-require@1.0.0
Demonstrate these symbols/APIs:
  - real-require.realImport

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:sha256:55094863593fc5ccd36c51f9b52421bd7d8e5d48bb013db35ea28c2a5b0e0359","contract":["realImport is exported as a callable function from real-require","realImport returns a Promise resolving to the module namespace for built-in modules","realImport dynamically imports installed packages by package name","realImport dynamically imports local ES modules via file URL and exposes named and default exports","realImport rejects with an error when attempting to import a nonexistent module","dynamicImport helper wraps realImport to load modules dynamically","importNamedExport helper retrieves a specific named export from a dynamically imported module"],"goal":"verify real-require.realImport in pkg:npm/real-require@1.0.0","kind":"HOW","packages":["pkg:npm/real-require@1.0.0"],"schemaVersion":1,"symbols":["real-require.realImport"]},"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/real-require@1.0.0"],"schemaVersion":1,"subject":"pkg:npm/real-require@1.0.0","symbols":["real-require.realImport"],"verifierAdapter":"node-typescript@1"}

export const greeting = 'hello from fixture';

export function calculateSum(a, b) {
  return a + b;
}

export default {
  type: 'fixture-module',
  active: true
};

{
  "name": "sample-real-require",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-real-require",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "real-require": "1.0.0"
      }
    },
    "node_modules/real-require": {
      "version": "1.0.0",
      "resolved": "https://registry.npmjs.org/real-require/-/real-require-1.0.0.tgz",
      "integrity": "sha512-P4nbQYQfePJxRSmY+v/KINxVucm4NF3p3s7pJveMTtom52FR4YGltUQLB8idDXwDDWW+eYrWDFbuzUnjoWHF7g==",
      "license": "MIT"
    }
  }
}

{
  "name": "sample-real-require",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room code sample for real-require@1.0.0",
  "main": "src/index.js",
  "license": "MIT-0",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "real-require": "1.0.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify real-require.realImport in pkg:npm/real-require@1.0.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/real-require@1.0.0"
  ],
  "symbols": [
    "real-require.realImport"
  ]
}

'use strict';

const { realImport, realRequire } = require('real-require');

/**
 * Dynamically imports a module by specifier or file URL using realImport.
 *
 * @param {string} specifier - Module specifier, path, or file URL.
 * @returns {Promise<any>} Module namespace object.
 */
async function dynamicImport(specifier) {
  return realImport(specifier);
}

/**
 * Dynamically imports a module and retrieves a specific named export.
 *
 * @param {string} specifier - Module specifier, path, or file URL.
 * @param {string} exportName - Name of the exported property to retrieve.
 * @returns {Promise<any>} The exported value.
 */
async function importNamedExport(specifier, exportName) {
  const moduleNamespace = await realImport(specifier);
  return moduleNamespace[exportName];
}

module.exports = {
  realImport,
  realRequire,
  dynamicImport,
  importNamedExport
};

import assert from 'node:assert/strict';
import { createRequire } from 'node:module';

const require = createRequire(import.meta.url);
const {
  realImport,
  realRequire,
  dynamicImport,
  importNamedExport
} = require('../src/index.js');

async function main() {
  // 1. realImport is exported as a callable function from real-require
  assert.equal(typeof realImport, 'function', 'realImport should be a function');
  assert.equal(typeof realRequire, 'function', 'realRequire should be a function');

  // 2. realImport returns a Promise resolving to the module namespace for built-in modules
  const pathModulePromise = realImport('node:path');
  assert(pathModulePromise instanceof Promise, 'realImport should return a Promise');
  const pathModule = await pathModulePromise;
  assert(pathModule !== null && typeof pathModule === 'object', 'Resolved module should be an object');
  assert.equal(typeof pathModule.join, 'function', 'pathModule should expose join function');
  assert.equal(pathModule.posix.join('foo', 'bar'), 'foo/bar', 'join should concatenate path segments');

  // 3. realImport dynamically imports installed packages by package name
  const selfPkg = await realImport('real-require');
  assert(selfPkg !== null && typeof selfPkg === 'object', 'Installed package should resolve to object');
  assert.equal(typeof selfPkg.realImport, 'function', 'Imported package should expose realImport');
  assert.equal(typeof selfPkg.realRequire, 'function', 'Imported package should expose realRequire');

  // 4. realImport dynamically imports local ES modules via file URL and exposes named and default exports
  const fixtureUrl = new URL('../fixtures/helper.mjs', import.meta.url).href;
  const fixture = await realImport(fixtureUrl);
  assert(fixture !== null && typeof fixture === 'object', 'Fixture module should resolve to namespace');
  assert.equal(fixture.greeting, 'hello from fixture', 'Named export greeting should match');
  assert.equal(typeof fixture.calculateSum, 'function', 'calculateSum should be a function');
  assert.equal(fixture.calculateSum(3, 4), 7, 'calculateSum(3, 4) should return 7');
  assert.equal(fixture.default.type, 'fixture-module', 'Default export type should match');
  assert.equal(fixture.default.active, true, 'Default export active should be true');

  // 5. realImport rejects with an error when attempting to import a nonexistent module
  await assert.rejects(
    async () => {
      await realImport('node:nonexistent_builtin_for_testing_purposes');
    },
    (err) => {
      assert(err instanceof Error, 'Rejected value should be an Error');
      assert(
        err.code === 'ERR_MODULE_NOT_FOUND' || err.code === 'ERR_UNKNOWN_BUILTIN_MODULE',
        `Unexpected error code: ${err.code}`
      );
      return true;
    }
  );

  // 6. dynamicImport helper wraps realImport to load modules dynamically
  const urlModule = await dynamicImport('node:url');
  assert(urlModule !== null && typeof urlModule === 'object', 'URL module should resolve');
  assert.equal(typeof urlModule.fileURLToPath, 'function', 'fileURLToPath should be a function');

  // 7. importNamedExport helper retrieves a specific named export from a dynamically imported module
  const joinFn = await importNamedExport('node:path', 'join');
  assert.equal(typeof joinFn, 'function', 'Retrieved named export join should be a function');
  const fixtureDefault = await importNamedExport(fixtureUrl, 'default');
  assert.equal(fixtureDefault.type, 'fixture-module', 'Retrieved default export property should match');

  console.log('All contract assertions passed successfully.');
}

main().catch((err) => {
  console.error('Contract test failed:', err);
  process.exit(1);
});