resolve.exports 2.0.3: resolve

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 resolve.exports.resolve in pkg:npm/resolve.exports@2.0.3
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/resolve.exports@2.0.3
Demonstrate these symbols/APIs:
  - resolve.exports.resolve
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: esm
  - packageManager: npm@10.9.8
  - runtime: node@22.23.2

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:b99dcba38bb575eac78a281f86a07803259aa0e7c5fc1f6c3d402cba8bef2b0d","constraints":{"executionContext":"node"},"contract":["resolve returns default entry point for root export specifier","resolve matches custom export conditions specified in options.conditions","resolve matches require condition when require option is true","resolve matches browser condition when browser option is true","resolve supports array fallbacks in export mapping","resolve resolves exact subpaths and package-prefixed subpaths","resolve resolves wildcard pattern subpaths","resolve resolves internal package imports specifiers starting with hash","resolve throws error when requested subpath specifier is missing","resolve throws error when exports specifier has no matching conditions"],"goal":"verify resolve.exports.resolve in pkg:npm/resolve.exports@2.0.3","kind":"HOW","packages":["pkg:npm/resolve.exports@2.0.3"],"schemaVersion":1,"symbols":["resolve.exports.resolve"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"esm","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/resolve.exports@2.0.3"],"schemaVersion":1,"subject":"pkg:npm/resolve.exports@2.0.3","symbols":["resolve.exports.resolve"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-resolve-exports-resolve",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-resolve-exports-resolve",
      "version": "1.0.0",
      "dependencies": {
        "resolve.exports": "2.0.3"
      }
    },
    "node_modules/resolve.exports": {
      "version": "2.0.3",
      "resolved": "https://registry.npmjs.org/resolve.exports/-/resolve.exports-2.0.3.tgz",
      "integrity": "sha512-OcXjMsGdhL4XnbShKpAcSqPMzQoYkYyhbEaeSko47MjRP9NfEQMhZkXL1DoFlt9LWQn4YttrdnV6X2OiyzBi+A==",
      "license": "MIT",
      "engines": {
        "node": ">=10"
      }
    }
  }
}

{
  "name": "sample-resolve-exports-resolve",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "dependencies": {
    "resolve.exports": "2.0.3"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify resolve.exports.resolve in pkg:npm/resolve.exports@2.0.3",
  "kind": "HOW",
  "packages": [
    "pkg:npm/resolve.exports@2.0.3"
  ],
  "symbols": [
    "resolve.exports.resolve"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "esm",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

import assert from 'node:assert/strict';
import { resolve } from 'resolve.exports';

// 1. resolve returns default entry point for root export specifier
{
  const pkg = {
    name: 'demo-pkg',
    exports: {
      '.': {
        import: './dist/index.mjs',
        require: './dist/index.cjs',
        default: './dist/index.js',
      },
    },
  };

  const resDot = resolve(pkg, '.');
  assert.deepEqual(resDot, ['./dist/index.mjs']);

  const resOmitted = resolve(pkg);
  assert.deepEqual(resOmitted, ['./dist/index.mjs']);

  const resPkgName = resolve(pkg, 'demo-pkg');
  assert.deepEqual(resPkgName, ['./dist/index.mjs']);
}

// 2. resolve matches custom export conditions specified in options.conditions
{
  const pkg = {
    name: 'demo-pkg',
    exports: {
      '.': {
        worker: './dist/worker.mjs',
        production: './dist/prod.mjs',
        default: './dist/index.mjs',
      },
    },
  };

  const resWorker = resolve(pkg, '.', { conditions: ['worker'] });
  assert.deepEqual(resWorker, ['./dist/worker.mjs']);

  const resProd = resolve(pkg, '.', { conditions: ['production'] });
  assert.deepEqual(resProd, ['./dist/prod.mjs']);
}

// 3. resolve matches require condition when require option is true
{
  const pkg = {
    name: 'demo-pkg',
    exports: {
      '.': {
        import: './dist/index.mjs',
        require: './dist/index.cjs',
      },
    },
  };

  const resRequire = resolve(pkg, '.', { require: true });
  assert.deepEqual(resRequire, ['./dist/index.cjs']);
}

// 4. resolve matches browser condition when browser option is true
{
  const pkg = {
    name: 'demo-pkg',
    exports: {
      '.': {
        browser: './dist/browser.mjs',
        node: './dist/node.mjs',
        default: './dist/index.mjs',
      },
    },
  };

  const resBrowser = resolve(pkg, '.', { browser: true });
  assert.deepEqual(resBrowser, ['./dist/browser.mjs']);

  const resNode = resolve(pkg, '.', { browser: false });
  assert.deepEqual(resNode, ['./dist/node.mjs']);
}

// 5. resolve supports array fallbacks in export mapping
{
  const pkg = {
    name: 'demo-pkg',
    exports: {
      './fallback': [
        { custom: './dist/custom.js' },
        './dist/fallback.js',
      ],
    },
  };

  const resWithoutCustom = resolve(pkg, './fallback');
  assert.deepEqual(resWithoutCustom, ['./dist/fallback.js']);

  const resWithCustom = resolve(pkg, './fallback', { conditions: ['custom'] });
  assert.deepEqual(resWithCustom, ['./dist/custom.js', './dist/fallback.js']);
}

// 6. resolve resolves exact subpaths and package-prefixed subpaths
{
  const pkg = {
    name: 'demo-pkg',
    exports: {
      './feature': './dist/feature.mjs',
      './utils/math': {
        import: './dist/math.mjs',
        require: './dist/math.cjs',
      },
    },
  };

  const resFeature = resolve(pkg, './feature');
  assert.deepEqual(resFeature, ['./dist/feature.mjs']);

  const resPrefixed = resolve(pkg, 'demo-pkg/feature');
  assert.deepEqual(resPrefixed, ['./dist/feature.mjs']);

  const resMath = resolve(pkg, 'demo-pkg/utils/math');
  assert.deepEqual(resMath, ['./dist/math.mjs']);
}

// 7. resolve resolves wildcard pattern subpaths
{
  const pkg = {
    name: 'demo-pkg',
    exports: {
      './components/*': './dist/components/*.mjs',
      './lib/*': './dist/lib/*.js',
    },
  };

  const resButton = resolve(pkg, './components/Button');
  assert.deepEqual(resButton, ['./dist/components/Button.mjs']);

  const resLib = resolve(pkg, 'demo-pkg/lib/helpers/dom');
  assert.deepEqual(resLib, ['./dist/lib/helpers/dom.js']);
}

// 8. resolve resolves internal package imports specifiers starting with hash
{
  const pkg = {
    name: 'demo-pkg',
    imports: {
      '#internal': {
        import: './src/internal.mjs',
        require: './src/internal.cjs',
      },
      '#utils/*': './src/utils/*.mjs',
    },
  };

  const resInternal = resolve(pkg, '#internal');
  assert.deepEqual(resInternal, ['./src/internal.mjs']);

  const resInternalWildcard = resolve(pkg, '#utils/crypto');
  assert.deepEqual(resInternalWildcard, ['./src/utils/crypto.mjs']);
}

// 9. resolve throws error when requested subpath specifier is missing
{
  const pkg = {
    name: 'demo-pkg',
    exports: {
      '.': './dist/index.js',
    },
  };

  assert.throws(
    () => resolve(pkg, './unknown'),
    /Missing "\.\/unknown" specifier in "demo-pkg" package/
  );
}

// 10. resolve throws error when exports specifier has no matching conditions
{
  const pkg = {
    name: 'demo-pkg',
    exports: {
      '.': {
        custom_only: './dist/custom.js',
      },
    },
  };

  assert.throws(
    () => resolve(pkg, '.', { conditions: [], unsafe: true }),
    /No known conditions for "\." specifier in "demo-pkg" package/
  );
}