postcss 8.5.26

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@8.5.26
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/postcss@8.5.26

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:sha256:2174332ee26764b4fa1514271f9ef3e3a01672f14328f206cd9b7226a8feb436","contract":["assert node.next, node.prev, container.index, container.first, container.last, container.some, and container.every navigate and query child nodes within AST containers","assert container.insertBefore, container.insertAfter, and container.removeAll modify container child lists and reset node references","assert result.warn and result.warnings record diagnostic warnings with AST node positions and preserve custom plugin messages","assert postcss.stringify and custom stringifiers serialize AST nodes and allow customizing emitted CSS output","assert decl.raws controls whitespace and colon spacing, decl.important appends !important flag, and cleanRaws normalizes formatting"],"goal":"verify pkg:npm/postcss@8.5.26","kind":"HOW","packages":["pkg:npm/postcss@8.5.26"],"schemaVersion":1},"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","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/postcss@8.5.26"],"schemaVersion":1,"subject":"pkg:npm/postcss@8.5.26","verifierAdapter":"node-typescript@1"}

{
  "name": "sample-postcss",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-postcss",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "postcss": "8.5.26"
      }
    },
    "node_modules/nanoid": {
      "version": "3.3.18",
      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.18.tgz",
      "integrity": "sha512-DTg4MJbGMWkfi6VZFdNt2/caMbQy4Ou+Op/hJQvGEWcnVfoA1QA+xzRKAzw9jD6+GVOOeYr/mIcuDSdug6F6+w==",
      "funding": [
        {
          "type": "github",
          "url": "https://github.com/sponsors/ai"
        }
      ],
      "license": "MIT",
      "bin": {
        "nanoid": "bin/nanoid.cjs"
      },
      "engines": {
        "node": "^10 || ^12 || ^13.7 || ^14 || >=15.0.1"
      }
    },
    "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/postcss": {
      "version": "8.5.26",
      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.26.tgz",
      "integrity": "sha512-u82N74LFzG8ca+dD8puPnplTXoGH4fTPpVGuIbt36G3qvNlkvfD0lEAZSxaly3KX8TS/L1A1gsCEmvKmBcVbkQ==",
      "funding": [
        {
          "type": "opencollective",
          "url": "https://opencollective.com/postcss/"
        },
        {
          "type": "tidelift",
          "url": "https://tidelift.com/funding/github/npm/postcss"
        },
        {
          "type": "github",
          "url": "https://github.com/sponsors/ai"
        }
      ],
      "license": "MIT",
      "dependencies": {
        "nanoid": "^3.3.17",
        "picocolors": "^1.1.1",
        "source-map-js": "^1.2.1"
      },
      "engines": {
        "node": "^10 || ^12 || >=14"
      }
    },
    "node_modules/source-map-js": {
      "version": "1.2.1",
      "resolved": "https://registry.npmjs.org/source-map-js/-/source-map-js-1.2.1.tgz",
      "integrity": "sha512-UXWMKhLOwVKb728IUtQPXxfYU+usdybtUrK/8uGE8CQMvrhOpwvzDBwj0QhSL7MQc7vIsISBG8VQ8+IDQxpfQA==",
      "license": "BSD-3-Clause",
      "engines": {
        "node": ">=0.10.0"
      }
    }
  }
}

{
  "name": "sample-postcss",
  "version": "1.0.0",
  "type": "module",
  "license": "MIT-0",
  "dependencies": {
    "postcss": "8.5.26"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/postcss@8.5.26",
  "kind": "HOW",
  "packages": [
    "pkg:npm/postcss@8.5.26"
  ]
}

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

const require = createRequire(import.meta.url);
const postcss = require('postcss');

// 1. assert node.next, node.prev, container.index, container.first, container.last, container.some, and container.every navigate and query child nodes within AST containers
{
  const css = `
    .card {
      color: #333333;
      margin: 10px;
      padding: 20px;
    }
  `;
  const root = postcss.parse(css);
  const rule = root.first;
  assert.equal(rule.type, 'rule');
  assert.equal(rule.selector, '.card');
  assert.equal(rule.nodes.length, 3);

  const firstDecl = rule.first;
  const lastDecl = rule.last;
  assert.equal(firstDecl.prop, 'color');
  assert.equal(lastDecl.prop, 'padding');

  const midDecl = firstDecl.next();
  assert.equal(midDecl.prop, 'margin');
  assert.equal(midDecl.prev(), firstDecl);
  assert.equal(midDecl.next(), lastDecl);
  assert.equal(lastDecl.next(), undefined);
  assert.equal(firstDecl.prev(), undefined);

  assert.equal(rule.index(firstDecl), 0);
  assert.equal(rule.index(midDecl), 1);
  assert.equal(rule.index(lastDecl), 2);

  assert.equal(rule.every((node) => node.type === 'decl'), true);
  assert.equal(rule.some((node) => node.prop === 'margin'), true);
  assert.equal(rule.some((node) => node.prop === 'nonexistent'), false);
}

// 2. assert container.insertBefore, container.insertAfter, and container.removeAll modify container child lists and reset node references
{
  const css = '.box { color: red; }';
  const root = postcss.parse(css);
  const rule = root.first;

  const bgDecl = postcss.decl({ prop: 'background', value: 'blue' });
  const fontDecl = postcss.decl({ prop: 'font-size', value: '14px' });

  rule.insertBefore(rule.first, bgDecl);
  assert.equal(rule.first.prop, 'background');
  assert.equal(rule.index(bgDecl), 0);

  rule.insertAfter(bgDecl, fontDecl);
  assert.equal(rule.index(fontDecl), 1);
  assert.equal(rule.nodes.length, 3);
  assert.deepEqual(
    rule.nodes.map((n) => n.prop),
    ['background', 'font-size', 'color']
  );

  rule.removeAll();
  assert.equal(rule.nodes.length, 0);
  assert.equal(rule.first, undefined);
  assert.equal(rule.last, undefined);
}

// 3. assert result.warn and result.warnings record diagnostic warnings with AST node positions and preserve custom plugin messages
{
  const testPlugin = () => {
    return {
      postcssPlugin: 'test-warning-plugin',
      Declaration(decl, { result }) {
        if (decl.prop === 'opacity') {
          result.warn('Opacity property found', {
            node: decl,
            word: 'opacity',
          });
        }
      },
      Once(root, { result }) {
        result.messages.push({
          type: 'dependency',
          plugin: 'test-warning-plugin',
          file: 'tokens.css',
        });
      },
    };
  };
  testPlugin.postcss = true;

  const css = '.alert { opacity: 0.5; color: black; }';
  const result = postcss([testPlugin]).process(css);

  const warnings = result.warnings();
  assert.equal(warnings.length, 1);
  assert.equal(warnings[0].plugin, 'test-warning-plugin');
  assert.equal(warnings[0].text, 'Opacity property found');
  assert.equal(warnings[0].line, 1);
  assert.equal(warnings[0].column, 10);
  assert.equal(warnings[0].word, 'opacity');
  assert.equal(warnings[0].toString(), 'test-warning-plugin: <css input>:1:10: Opacity property found');

  assert.equal(result.messages.length, 2);
  const depMsg = result.messages.find((m) => m.type === 'dependency');
  assert.ok(depMsg);
  assert.equal(depMsg.file, 'tokens.css');
}

// 4. assert postcss.stringify and custom stringifiers serialize AST nodes and allow customizing emitted CSS output
{
  const root = postcss.root();
  const rule = postcss.rule({ selector: 'a' });
  rule.append(postcss.decl({ prop: 'color', value: 'blue' }));
  root.append(rule);

  const chunks = [];
  postcss.stringify(root, (chunk, node, type) => {
    chunks.push({ chunk, nodeType: node ? node.type : null, type });
  });

  assert.ok(chunks.length > 0);
  assert.equal(chunks.map((c) => c.chunk).join(''), 'a {\n    color: blue\n}');

  const customStringifier = (node, builder) => {
    if (node.type === 'decl') {
      builder(`${node.prop}=>${node.value};`, node);
    } else if (node.type === 'rule') {
      builder(`${node.selector}[`, node, 'start');
      node.nodes.forEach((child) => customStringifier(child, builder));
      builder(']', node, 'end');
    } else if (node.type === 'root') {
      node.nodes.forEach((child) => customStringifier(child, builder));
    }
  };

  const customOutput = root.toString(customStringifier);
  assert.equal(customOutput, 'a[color=>blue;]');
}

// 5. assert decl.raws controls whitespace and colon spacing, decl.important appends !important flag, and cleanRaws normalizes formatting
{
  const root = postcss.parse('.box { color: red; }');
  const decl = root.first.first;
  assert.equal(decl.prop, 'color');
  assert.equal(decl.value, 'red');
  assert.equal(Boolean(decl.important), false);

  decl.important = true;
  assert.equal(decl.toString(), 'color: red !important');

  decl.raws.between = '  :   ';
  decl.raws.before = '\n  ';
  assert.equal(decl.toString(), 'color  :   red !important');
  assert.equal(root.toString(), '.box {\n  color  :   red !important; }');

  decl.cleanRaws();
  assert.equal(decl.raws.between, undefined);
  assert.equal(decl.raws.before, undefined);
  assert.equal(decl.toString(), 'color: red !important');
}