rrweb-cssom 0.7.1: CSSImportRule

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 rrweb-cssom.CSSImportRule in pkg:npm/rrweb-cssom@0.7.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/rrweb-cssom@0.7.1
Demonstrate these symbols/APIs:
  - rrweb-cssom.CSSImportRule

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:sha256:979f382d16cd9fc4b07dc3c591cd67bc371385c19f1dde1aae6091e0439f6477","contract":["CSSImportRule initializes with type 3 (IMPORT_RULE), empty href, and MediaList and CSSStyleSheet instances","CSSImportRule serializes href and optional media query to cssText format","CSSImportRule parses url, quotes, and media condition when assigning cssText","parse extracts CSSImportRule from CSS @import rules with href, media, and parent style sheet references"],"goal":"verify rrweb-cssom.CSSImportRule in pkg:npm/rrweb-cssom@0.7.1","kind":"HOW","packages":["pkg:npm/rrweb-cssom@0.7.1"],"schemaVersion":1,"symbols":["rrweb-cssom.CSSImportRule"]},"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/rrweb-cssom@0.7.1"],"schemaVersion":1,"subject":"pkg:npm/rrweb-cssom@0.7.1","symbols":["rrweb-cssom.CSSImportRule"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-rrweb-cssom-cssimportrule",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-rrweb-cssom-cssimportrule",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "rrweb-cssom": "0.7.1"
      }
    },
    "node_modules/rrweb-cssom": {
      "version": "0.7.1",
      "resolved": "https://registry.npmjs.org/rrweb-cssom/-/rrweb-cssom-0.7.1.tgz",
      "integrity": "sha512-TrEMa7JGdVm0UThDJSx7ddw5nVm3UJS9o9CCIZ72B1vSyEZoziDqBYP3XIoi/12lKrJR8rE3jeFHMok2F/Mnsg==",
      "license": "MIT"
    }
  }
}

{
  "name": "sample-rrweb-cssom-cssimportrule",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification sample for rrweb-cssom CSSImportRule",
  "main": "src/index.js",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "rrweb-cssom": "0.7.1"
  },
  "license": "MIT-0"
}

{
  "schemaVersion": 1,
  "goal": "verify rrweb-cssom.CSSImportRule in pkg:npm/rrweb-cssom@0.7.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/rrweb-cssom@0.7.1"
  ],
  "symbols": [
    "rrweb-cssom.CSSImportRule"
  ]
}

'use strict';

const {
  parse,
  CSSImportRule,
  CSSRule,
  CSSStyleSheet,
  MediaList,
} = require('rrweb-cssom');

function parseImportRules(cssText) {
  const stylesheet = parse(cssText);
  return Array.from(stylesheet.cssRules).filter(
    (rule) => rule instanceof CSSImportRule
  );
}

function createImportRule(href, mediaQuery) {
  const rule = new CSSImportRule();
  if (href !== undefined) {
    rule.href = href;
  }
  if (mediaQuery) {
    rule.media.mediaText = mediaQuery;
  }
  return rule;
}

function setImportRuleCssText(rule, cssText) {
  rule.cssText = cssText;
  return {
    href: rule.href,
    mediaText: rule.media.mediaText,
  };
}

module.exports = {
  parse,
  CSSImportRule,
  CSSRule,
  CSSStyleSheet,
  MediaList,
  parseImportRules,
  createImportRule,
  setImportRuleCssText,
};

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

const require = createRequire(import.meta.url);
const {
  CSSImportRule,
  CSSRule,
  CSSStyleSheet,
  MediaList,
  parseImportRules,
  createImportRule,
  setImportRuleCssText,
} = require('../src/index.js');

// 1. CSSImportRule initializes with type 3 (IMPORT_RULE), empty href, and MediaList and CSSStyleSheet instances
{
  const rule = createImportRule();
  assert(rule instanceof CSSImportRule, 'rule must be instance of CSSImportRule');
  assert(rule instanceof CSSRule, 'rule must be instance of CSSRule');
  assert.strictEqual(rule.type, 3, 'rule.type must be numeric 3');
  assert.strictEqual(rule.type, CSSRule.IMPORT_RULE, 'rule.type must equal CSSRule.IMPORT_RULE');
  assert.strictEqual(rule.href, '', 'initial href must be empty string');
  assert(rule.media instanceof MediaList, 'rule.media must be instance of MediaList');
  assert(rule.styleSheet instanceof CSSStyleSheet, 'rule.styleSheet must be instance of CSSStyleSheet');
  assert.strictEqual(rule.parentRule, null, 'parentRule must be null initially');
  assert.strictEqual(rule.parentStyleSheet, null, 'parentStyleSheet must be null initially');
}

// 2. CSSImportRule serializes href and optional media query to cssText format
{
  const ruleWithoutMedia = createImportRule('reset.css');
  assert.strictEqual(ruleWithoutMedia.cssText, '@import url(reset.css);', 'cssText without media query must match');

  const ruleWithMedia = createImportRule('responsive.css', 'screen and (max-width: 768px)');
  assert.strictEqual(
    ruleWithMedia.cssText,
    '@import url(responsive.css) screen and (max-width: 768px);',
    'cssText with media query must match'
  );
}

// 3. CSSImportRule parses url, quotes, and media condition when assigning cssText
{
  const rule1 = createImportRule();
  const parsed1 = setImportRuleCssText(rule1, "@import url('theme.css') print, projection;");
  assert.strictEqual(parsed1.href, 'theme.css', 'href extracted from url() with quotes');
  assert.strictEqual(parsed1.mediaText, 'print, projection', 'media query extracted');

  const rule2 = createImportRule();
  const parsed2 = setImportRuleCssText(rule2, '@import "mobile.css";');
  assert.strictEqual(parsed2.href, 'mobile.css', 'href extracted from double quotes');
  assert.strictEqual(parsed2.mediaText, '', 'media query is empty when omitted');

  const rule3 = createImportRule();
  const parsed3 = setImportRuleCssText(rule3, '@import url(bundle.css);');
  assert.strictEqual(parsed3.href, 'bundle.css', 'href extracted from unquoted url()');
  assert.strictEqual(parsed3.mediaText, '', 'media query is empty when omitted');
}

// 4. parse extracts CSSImportRule from CSS @import rules with href, media, and parent style sheet references
{
  const css = '@import url("base.css") all;\n@import "print.css" print;\nbody { margin: 0; }';
  const importRules = parseImportRules(css);
  assert.strictEqual(importRules.length, 2, 'Should parse exactly two CSSImportRules');

  const firstRule = importRules[0];
  assert(firstRule instanceof CSSImportRule, 'first rule must be CSSImportRule');
  assert.strictEqual(firstRule.type, 3, 'first rule type must be 3');
  assert.strictEqual(firstRule.href, 'base.css', 'first rule href must match');
  assert.strictEqual(firstRule.media.mediaText, 'all', 'first rule mediaText must match');
  assert(firstRule.parentStyleSheet !== null, 'first rule parentStyleSheet must be set');
  assert.strictEqual(firstRule.styleSheet.parentStyleSheet, firstRule.parentStyleSheet, 'nested styleSheet parent must link back');

  const secondRule = importRules[1];
  assert(secondRule instanceof CSSImportRule, 'second rule must be CSSImportRule');
  assert.strictEqual(secondRule.type, 3, 'second rule type must be 3');
  assert.strictEqual(secondRule.href, 'print.css', 'second rule href must match');
  assert.strictEqual(secondRule.media.mediaText, 'print', 'second rule mediaText must match');
}

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