postcss-selector-parser 7.1.1

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/postcss-selector-parser@7.1.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/postcss-selector-parser@7.1.1

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:acb4a6b92c7ff4be73ec3e9c7c6c2d427c18d8f49de339d5cd753a0eaa0cb9aa","contract":["parser is exported as a function and creates a processor instance","parser transforms class selectors in a CSS selector string synchronously","parser parses compound selectors and combinators into an AST hierarchy","parser AST nodes support tag, class, id, and attribute selector types","parser builder functions construct selector nodes programmatically"],"goal":"verify pkg:npm/postcss-selector-parser@7.1.1","kind":"HOW","packages":["pkg:npm/postcss-selector-parser@7.1.1"],"schemaVersion":1},"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/postcss-selector-parser@7.1.1"],"schemaVersion":1,"subject":"pkg:npm/postcss-selector-parser@7.1.1","verifierAdapter":"node-typescript@1"}

import parser from 'postcss-selector-parser';

export const parse = parser;

/**
 * Synchronously parses a CSS selector string into an AST.
 *
 * @param {string} selector - CSS selector string to parse.
 * @returns {object} Root AST node.
 */
export function parseSelector(selector) {
  return parser().astSync(selector);
}

/**
 * Transforms class selectors in a CSS selector string using a mapping function.
 *
 * @param {string} selector - CSS selector string.
 * @param {function(string): string} rename - Mapping function for class names.
 * @returns {string} Transformed selector string.
 */
export function renameClasses(selector, rename) {
  const transform = (selectors) => {
    selectors.walkClasses((node) => {
      node.value = rename(node.value);
    });
  };
  return parser(transform).processSync(selector);
}

export default parser;

{
  "name": "sample-postcss-selector-parser",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-postcss-selector-parser",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "postcss-selector-parser": "7.1.1"
      }
    },
    "node_modules/cssesc": {
      "version": "3.0.0",
      "resolved": "https://registry.npmjs.org/cssesc/-/cssesc-3.0.0.tgz",
      "integrity": "sha512-/Tb/JcjK111nNScGob5MNtsntNM1aCNUDipB/TkwZFhyDrrE47SOx/18wF2bbjgc3ZzCSKW1T5nt5EbFoAz/Vg==",
      "license": "MIT",
      "bin": {
        "cssesc": "bin/cssesc"
      },
      "engines": {
        "node": ">=4"
      }
    },
    "node_modules/postcss-selector-parser": {
      "version": "7.1.1",
      "resolved": "https://registry.npmjs.org/postcss-selector-parser/-/postcss-selector-parser-7.1.1.tgz",
      "integrity": "sha512-orRsuYpJVw8LdAwqqLykBj9ecS5/cRHlI5+nvTo8LcCKmzDmqVORXtOIYEEQuL9D4BxtA1lm5isAqzQZCoQ6Eg==",
      "license": "MIT",
      "dependencies": {
        "cssesc": "^3.0.0",
        "util-deprecate": "^1.0.2"
      },
      "engines": {
        "node": ">=4"
      }
    },
    "node_modules/util-deprecate": {
      "version": "1.0.2",
      "resolved": "https://registry.npmjs.org/util-deprecate/-/util-deprecate-1.0.2.tgz",
      "integrity": "sha512-EPD5q1uXyFxJpCrLnCc1nHnq3gOa6DZBocAIiI2TaSCA7VCJ1UJDMagCzIkXNsUYfD1daK//LTEQ8xiIbrHtcw==",
      "license": "MIT"
    }
  }
}

{
  "name": "sample-postcss-selector-parser",
  "version": "1.0.0",
  "type": "module",
  "main": "index.mjs",
  "license": "MIT-0",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "postcss-selector-parser": "7.1.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/postcss-selector-parser@7.1.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/postcss-selector-parser@7.1.1"
  ]
}

import assert from 'node:assert/strict';
import parser from 'postcss-selector-parser';
import { parseSelector, renameClasses } from '../index.mjs';

// 1. parser is exported as a function and creates a processor instance
assert.equal(typeof parser, 'function');
const processor = parser();
assert.equal(typeof processor.processSync, 'function');
assert.equal(typeof processor.astSync, 'function');

// 2. parser transforms class selectors in a CSS selector string synchronously
const transformed = renameClasses('.old-btn > .active', (cls) => `new-${cls}`);
assert.equal(transformed, '.new-old-btn > .new-active');

const customTransform = parser((selectors) => {
  selectors.walkClasses((cls) => {
    cls.value = 'renamed';
  });
}).processSync('div.foo, span.bar');
assert.equal(customTransform, 'div.renamed, span.renamed');

// 3. parser parses compound selectors and combinators into an AST hierarchy
const root = parseSelector('div.card > span#header');
assert.equal(root.type, 'root');
assert.equal(root.nodes.length, 1);

const selectorNode = root.nodes[0];
assert.equal(selectorNode.type, 'selector');
assert.equal(selectorNode.nodes.length, 5);

const [tag1, class1, combinator, tag2, id1] = selectorNode.nodes;
assert.equal(tag1.type, 'tag');
assert.equal(tag1.value, 'div');
assert.equal(class1.type, 'class');
assert.equal(class1.value, 'card');
assert.equal(combinator.type, 'combinator');
assert.equal(combinator.value, '>');
assert.equal(tag2.type, 'tag');
assert.equal(tag2.value, 'span');
assert.equal(id1.type, 'id');
assert.equal(id1.value, 'header');

// 4. parser AST nodes support tag, class, id, and attribute selector types
const attrRoot = parseSelector('[data-role="primary"]');
const attrNode = attrRoot.nodes[0].nodes[0];
assert.equal(attrNode.type, 'attribute');
assert.equal(attrNode.attribute, 'data-role');
assert.equal(attrNode.value, 'primary');

// 5. parser builder functions construct selector nodes programmatically
const builtClass = parser.className({ value: 'button' });
assert.equal(builtClass.type, 'class');
assert.equal(builtClass.toString(), '.button');

const builtId = parser.id({ value: 'root' });
assert.equal(builtId.type, 'id');
assert.equal(builtId.toString(), '#root');

const builtTag = parser.tag({ value: 'article' });
assert.equal(builtTag.type, 'tag');
assert.equal(builtTag.toString(), 'article');

const builtAttr = parser.attribute({ attribute: 'disabled' });
assert.equal(builtAttr.type, 'attribute');
assert.equal(builtAttr.toString(), '[disabled]');

console.log('All postcss-selector-parser contract assertions passed.');