browserslist 4.28.9: parse

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/browserslist@4.28.9
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/browserslist@4.28.9
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - 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:sha256:3e78590ccbf300318eb30c636e9e24977037fc50bd474d88db8b81d1f8329ac2","constraints":{"executionContext":"node"},"contract":["browserslist.parse decomposes query strings into structured descriptor objects with query type and browser target","browserslist.parse supports regional popularity queries with sign, popularity percentage, and place code","browserslist.parse parses an array of queries and comma-separated query strings identically","browserslist.parse identifies boolean compositions with compose and query negation with not flag","browserslist.parse on empty string or empty array returns an empty descriptor list","browserslist.parse with undefined defaults to parsing queries defined in browserslist.defaults","browserslist.parse marks unclassified or unrecognized query syntax as type unknown rather than throwing","browserslist.parse throws BrowserslistError when passed non-array and non-string argument types"],"goal":"verify pkg:npm/browserslist@4.28.9","kind":"HOW","packages":["pkg:npm/browserslist@4.28.9"],"schemaVersion":1,"symbols":["browserslist.parse"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"cjs","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/browserslist@4.28.9"],"schemaVersion":1,"subject":"pkg:npm/browserslist@4.28.9","symbols":["browserslist.parse"],"verifierAdapter":"node-typescript@1"}

const browserslist = require('browserslist');

/**
 * Parses query strings or query arrays into structured AST descriptor objects.
 *
 * @param {string | string[]} queries - Browserslist query or array of queries.
 * @param {object} [opts] - Optional configuration options.
 * @returns {Array<object>} Array of parsed query descriptors.
 */
function parseQueries(queries, opts) {
  return browserslist.parse(queries, opts);
}

module.exports = {
  browserslist,
  parseQueries,
};

{
  "name": "sample-browserslist-parse",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-browserslist-parse",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "browserslist": "4.28.9"
      }
    },
    "node_modules/baseline-browser-mapping": {
      "version": "2.11.21",
      "resolved": "https://registry.npmjs.org/baseline-browser-mapping/-/baseline-browser-mapping-2.11.21.tgz",
      "integrity": "sha512-uh8vpY/1/YyFkunIDFH/12p7/7VdPKA1hejMVEbdkEaWnUz0Hesvx5EbiU6XxjyHZIOju+ZMbQJkRh+es3/spQ==",
      "license": "Apache-2.0",
      "bin": {
        "baseline-browser-mapping": "dist/cli.cjs"
      },
      "engines": {
        "node": ">=6.0.0"
      }
    },
    "node_modules/browserslist": {
      "version": "4.28.9",
      "resolved": "https://registry.npmjs.org/browserslist/-/browserslist-4.28.9.tgz",
      "integrity": "sha512-EWazOblFYUvlGZcfGhPUPmYh3nikUxBVb+y9MJun5f3hBi812X+8MSQTujLBtgK3cf51fJWbWfOjyeO954d+Eg==",
      "funding": [
        {
          "type": "opencollective",
          "url": "https://opencollective.com/browserslist"
        },
        {
          "type": "tidelift",
          "url": "https://tidelift.com/funding/github/npm/browserslist"
        },
        {
          "type": "github",
          "url": "https://github.com/sponsors/ai"
        }
      ],
      "license": "MIT",
      "dependencies": {
        "baseline-browser-mapping": "^2.11.20",
        "caniuse-lite": "^1.0.30001810",
        "electron-to-chromium": "^1.5.420",
        "node-releases": "^2.0.54",
        "update-browserslist-db": "^1.3.2"
      },
      "bin": {
        "browserslist": "cli.js"
      },
      "engines": {
        "node": "^6 || ^7 || ^8 || ^9 || ^10 || ^11 || ^12 || >=13.7"
      }
    },
    "node_modules/caniuse-lite": {
      "version": "1.0.30001810",
      "resolved": "https://registry.npmjs.org/caniuse-lite/-/caniuse-lite-1.0.30001810.tgz",
      "integrity": "sha512-TITQPUkaz+aVk5GL6NhOdwk1aEaNTSDPsGFWrTuhKGtjTF70jL/Oht2W4c6rXUe5fu7Ie19VIahAXHIIiWWNeg==",
      "funding": [
        {
          "type": "opencollective",
          "url": "https://opencollective.com/browserslist"
        },
        {
          "type": "tidelift",
          "url": "https://tidelift.com/funding/github/npm/caniuse-lite"
        },
        {
          "type": "github",
          "url": "https://github.com/sponsors/ai"
        }
      ],
      "license": "CC-BY-4.0"
    },
    "node_modules/electron-to-chromium": {
      "version": "1.5.422",
      "resolved": "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.5.422.tgz",
      "integrity": "sha512-UvA/32XqrLDdZSn7Jllo1AYNcWji/G0d5M0GTViE7KoGBiMunw3a34Sb2KO4ZZyrSEhqsxFoVhWWJshdyfKqJA==",
      "license": "ISC"
    },
    "node_modules/escalade": {
      "version": "3.2.0",
      "resolved": "https://registry.npmjs.org/escalade/-/escalade-3.2.0.tgz",
      "integrity": "sha512-WUj2qlxaQtO4g6Pq5c29GTcWGDyd8itL8zTlipgECz3JesAiiOKotd8JU6otB3PACgG6xkJUyVhboMS+bje/jA==",
      "license": "MIT",
      "engines": {
        "node": ">=6"
      }
    },
    "node_modules/node-releases": {
      "version": "2.0.54",
      "resolved": "https://registry.npmjs.org/node-releases/-/node-releases-2.0.54.tgz",
      "integrity": "sha512-YHs7BmmcsdAI5Ozuf8JZo6PT0mv2GIWC9vMfvUC3dp65M8hn7Ux8CPL+2oBI7juNuj9d0ndhTcznq2ODBps9cQ==",
      "license": "MIT",
      "engines": {
        "node": ">=18"
      }
    },
    "node_modules/picocolors": {
      "version": "1.1.1",
      "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.1.1.tgz",
      "integrity": "sha512-xceH2snhtb5M9liqDsmEw56le376mTZkEX/jEb/RxNFyegNul7eNslCXP9FDj/Lcu0X8KEyMceP2ntpaHrDEVA==",
      "license": "ISC"
    },
    "node_modules/update-browserslist-db": {
      "version": "1.3.2",
      "resolved": "https://registry.npmjs.org/update-browserslist-db/-/update-browserslist-db-1.3.2.tgz",
      "integrity": "sha512-UQ+MSxlhRm1bzjhU+DcuXfjFO1FzNtqhK5+9Yvlp90ItDLk5vT932A0rFu619nf7RVS+Y/VeaUW1jaRDqZ8VJw==",
      "funding": [
        {
          "type": "opencollective",
          "url": "https://opencollective.com/browserslist"
        },
        {
          "type": "tidelift",
          "url": "https://tidelift.com/funding/github/npm/browserslist"
        },
        {
          "type": "github",
          "url": "https://github.com/sponsors/ai"
        }
      ],
      "license": "MIT",
      "dependencies": {
        "escalade": "^3.2.0",
        "picocolors": "^1.1.1"
      },
      "bin": {
        "update-browserslist-db": "cli.js"
      },
      "peerDependencies": {
        "browserslist": ">= 4.21.0"
      }
    }
  }
}

{
  "name": "sample-browserslist-parse",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room sample verifying browserslist.parse AST descriptor resolution",
  "main": "index.js",
  "license": "MIT-0",
  "dependencies": {
    "browserslist": "4.28.9"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/browserslist@4.28.9",
  "kind": "HOW",
  "packages": [
    "pkg:npm/browserslist@4.28.9"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

import assert from 'node:assert/strict';
import browserslist from 'browserslist';
import { parseQueries } from '../index.js';

// 1. browserslist.parse decomposes query strings into structured descriptor objects with query type and browser target
const lastChrome = browserslist.parse('last 2 chrome versions');
assert.deepStrictEqual(lastChrome, [
  {
    query: 'last 2 chrome versions',
    type: 'last_browser_versions',
    versions: '2',
    browser: 'chrome',
    compose: 'or'
  }
]);
assert.deepStrictEqual(parseQueries('last 2 chrome versions'), lastChrome);

// 2. browserslist.parse supports regional popularity queries with sign, popularity percentage, and place code
const popularityUS = browserslist.parse('> 1% in US');
assert.deepStrictEqual(popularityUS, [
  {
    query: '> 1% in US',
    type: 'popularity_in_place',
    sign: '>',
    popularity: '1',
    place: 'US',
    compose: 'or'
  }
]);

// 3. browserslist.parse parses an array of queries and comma-separated query strings identically
const fromArray = browserslist.parse(['chrome > 100', 'ie 11']);
const fromString = browserslist.parse('chrome > 100, ie 11');
assert.deepStrictEqual(fromString, [
  {
    query: 'chrome > 100',
    type: 'browser_ray',
    browser: 'chrome',
    sign: '>',
    version: '100',
    compose: 'or'
  },
  {
    query: 'ie 11',
    type: 'browser_version',
    browser: 'ie',
    version: '11',
    compose: 'or'
  }
]);
assert.deepStrictEqual(fromArray, fromString);

// 4. browserslist.parse identifies boolean compositions with compose and query negation with not flag
const composed = browserslist.parse('dead and not chrome > 100');
assert.deepStrictEqual(composed, [
  { query: 'dead', type: 'dead', compose: 'or' },
  {
    query: 'not chrome > 100',
    not: true,
    type: 'browser_ray',
    browser: 'chrome',
    sign: '>',
    version: '100',
    compose: 'and'
  }
]);

// 5. browserslist.parse on empty string or empty array returns an empty descriptor list
assert.deepStrictEqual(browserslist.parse(''), []);
assert.deepStrictEqual(browserslist.parse([]), []);

// 6. browserslist.parse with undefined defaults to parsing queries defined in browserslist.defaults
const defaultDescriptors = browserslist.parse();
assert.ok(Array.isArray(defaultDescriptors) && defaultDescriptors.length === browserslist.defaults.length);
assert.strictEqual(defaultDescriptors[0].query, browserslist.defaults[0]);

// 7. browserslist.parse marks unclassified or unrecognized query syntax as type unknown rather than throwing
const unknownResult = browserslist.parse('unknown syntax @#$');
assert.deepStrictEqual(unknownResult, [
  {
    query: 'unknown syntax @#$',
    type: 'unknown',
    compose: 'or'
  }
]);

// 8. browserslist.parse throws BrowserslistError when passed non-array and non-string argument types
assert.throws(
  () => browserslist.parse(123),
  (err) => err.name === 'BrowserslistError' && err.message.includes('Browser queries must be an array or string. Got number.')
);

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