postcss-value-parser 4.2.0: ValueParser.stringify

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 ValueParser.stringify in pkg:npm/postcss-value-parser@4.2.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/postcss-value-parser@4.2.0
Demonstrate these symbols/APIs:
  - ValueParser.stringify

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:sha256:0ea717071f13d6bd6d6e6f2330b0527a3f23cac8f083eb06f218b8919faa1bef","contract":["assert ValueParser.stringify serializes parsed AST nodes and constructed node arrays into CSS value strings","assert ValueParser.stringify serializes single AST nodes directly","assert ValueParser.stringify applies custom stringifier callback to transform specific AST nodes","assert ValueParser.stringify serializes function nodes with nested argument nodes and handles unclosed functions","assert ValueParser.stringify preserves quotes for closed and unclosed string nodes","assert ValueParser.stringify preserves comments with closed and unclosed syntax","assert ValueParser.stringify formats divider nodes with leading and trailing whitespace","assert ValueParser.stringify handles empty node arrays and empty function bodies"],"goal":"verify ValueParser.stringify in pkg:npm/postcss-value-parser@4.2.0","kind":"HOW","packages":["pkg:npm/postcss-value-parser@4.2.0"],"schemaVersion":1,"symbols":["ValueParser.stringify"]},"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/postcss-value-parser@4.2.0"],"schemaVersion":1,"subject":"pkg:npm/postcss-value-parser@4.2.0","symbols":["ValueParser.stringify"],"verifierAdapter":"node-typescript@1"}

const ValueParser = require('postcss-value-parser');

function stringifyNodes(nodes, customCallback) {
  return ValueParser.stringify(nodes, customCallback);
}

function stringifySingleNode(node, customCallback) {
  return ValueParser.stringify(node, customCallback);
}

function transformWithCustomStringifier(nodes, transformFn) {
  return ValueParser.stringify(nodes, transformFn);
}

function createFunctionNode(name, nodes = [], options = {}) {
  return {
    type: 'function',
    value: name,
    nodes,
    before: options.before || '',
    after: options.after || '',
    unclosed: Boolean(options.unclosed),
  };
}

function createStringNode(value, quote = '"', unclosed = false) {
  return {
    type: 'string',
    value,
    quote,
    unclosed,
  };
}

function createCommentNode(value, unclosed = false) {
  return {
    type: 'comment',
    value,
    unclosed,
  };
}

function createDivNode(value = ',', before = '', after = ' ') {
  return {
    type: 'div',
    value,
    before,
    after,
  };
}

module.exports = {
  ValueParser,
  stringify: ValueParser.stringify,
  stringifyNodes,
  stringifySingleNode,
  transformWithCustomStringifier,
  createFunctionNode,
  createStringNode,
  createCommentNode,
  createDivNode,
};

{
  "name": "sample-postcss-value-parser",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-postcss-value-parser",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "postcss-value-parser": "4.2.0"
      }
    },
    "node_modules/postcss-value-parser": {
      "version": "4.2.0",
      "resolved": "https://registry.npmjs.org/postcss-value-parser/-/postcss-value-parser-4.2.0.tgz",
      "integrity": "sha512-1NNCs6uurfkVbeXG4S8JFT9t19m45ICnif8zWLd5oPSZ50QnwMfK+H3jv408d4jw/7Bttv5axS5IiHoLaVNHeQ==",
      "license": "MIT"
    }
  }
}

{
  "name": "sample-postcss-value-parser",
  "version": "1.0.0",
  "description": "Minimal clean-room sample verifying ValueParser.stringify in postcss-value-parser",
  "main": "index.js",
  "license": "MIT-0",
  "dependencies": {
    "postcss-value-parser": "4.2.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify ValueParser.stringify in pkg:npm/postcss-value-parser@4.2.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/postcss-value-parser@4.2.0"
  ],
  "symbols": [
    "ValueParser.stringify"
  ]
}

import assert from 'node:assert';
import ValueParser from 'postcss-value-parser';
import samplePkg from '../index.js';

const {
  stringifyNodes,
  stringifySingleNode,
  transformWithCustomStringifier,
  createFunctionNode,
  createStringNode,
  createCommentNode,
  createDivNode,
} = samplePkg;

// 1. ValueParser.stringify serializes a list of AST nodes back into a CSS value string
const parsed = ValueParser('10px solid #333');
const strFromParsed = ValueParser.stringify(parsed.nodes);
assert.strictEqual(strFromParsed, '10px solid #333', 'Must stringify parsed AST nodes accurately');

const manualNodes = [
  { type: 'word', value: '2rem' },
  { type: 'space', value: ' ' },
  { type: 'word', value: 'sans-serif' },
];
const strFromManual = stringifyNodes(manualNodes);
assert.strictEqual(strFromManual, '2rem sans-serif', 'Must stringify constructed node array');

// 2. ValueParser.stringify serializes a single AST node directly
const singleWordNode = { type: 'word', value: 'inline-block' };
const singleResult = stringifySingleNode(singleWordNode);
assert.strictEqual(singleResult, 'inline-block', 'Single word node must stringify to its value');

// 3. ValueParser.stringify applies custom stringifier callback to transform specific AST nodes
const rawValue = 'margin: 10px 20px 30px';
const valueAst = ValueParser(rawValue);
const transformed = transformWithCustomStringifier(valueAst.nodes, (node) => {
  if (node.type === 'word' && node.value.endsWith('px')) {
    const num = parseInt(node.value, 10);
    return `${num * 2}px`;
  }
  return undefined;
});
assert.strictEqual(
  transformed,
  'margin: 20px 40px 60px',
  'Custom callback should replace matched nodes and fall back for others'
);

// 4. ValueParser.stringify serializes function nodes including nested arguments and parentheses
const fnNode = createFunctionNode('rgba', [
  { type: 'word', value: '255' },
  { type: 'div', value: ',', before: '', after: ' ' },
  { type: 'word', value: '0' },
  { type: 'div', value: ',', before: '', after: ' ' },
  { type: 'word', value: '128' },
  { type: 'div', value: ',', before: '', after: ' ' },
  { type: 'word', value: '0.8' },
]);
assert.strictEqual(
  stringifySingleNode(fnNode),
  'rgba(255, 0, 128, 0.8)',
  'Function node must stringify with arguments and parentheses'
);

const unclosedFnNode = createFunctionNode('calc', [{ type: 'word', value: '100%' }], {
  unclosed: true,
});
assert.strictEqual(
  stringifySingleNode(unclosedFnNode),
  'calc(100%',
  'Unclosed function node must omit closing parenthesis'
);

// 5. ValueParser.stringify preserves quotes for closed and unclosed string nodes
const doubleQuoted = createStringNode('Arial', '"', false);
assert.strictEqual(stringifySingleNode(doubleQuoted), '"Arial"', 'Double quoted string node');

const singleQuoted = createStringNode('Times New Roman', "'", false);
assert.strictEqual(stringifySingleNode(singleQuoted), "'Times New Roman'", 'Single quoted string node');

const unclosedString = createStringNode('unclosed text', '"', true);
assert.strictEqual(stringifySingleNode(unclosedString), '"unclosed text', 'Unclosed string node omits trailing quote');

// 6. ValueParser.stringify preserves comments with closed and unclosed syntax
const standardComment = createCommentNode(' theme accent ', false);
assert.strictEqual(stringifySingleNode(standardComment), '/* theme accent */', 'Closed comment formatting');

const unclosedComment = createCommentNode(' unclosed banner', true);
assert.strictEqual(stringifySingleNode(unclosedComment), '/* unclosed banner', 'Unclosed comment omits trailing delimiter');

// 7. ValueParser.stringify formats divider nodes with leading and trailing whitespace
const commaDivider = createDivNode(',', ' ', ' ');
assert.strictEqual(stringifySingleNode(commaDivider), ' , ', 'Divider with before and after spaces');

const slashDivider = createDivNode('/', '', ' ');
assert.strictEqual(stringifySingleNode(slashDivider), '/ ', 'Divider with trailing space only');

// 8. ValueParser.stringify handles empty node arrays and empty function bodies
assert.strictEqual(stringifyNodes([]), '', 'Empty array must stringify to empty string');

const emptyFn = createFunctionNode('url', []);
assert.strictEqual(stringifySingleNode(emptyFn), 'url()', 'Empty function must stringify to name()');

console.log('All ValueParser.stringify contract assertions passed.');