entities 6.0.1: decodeHTMLAttribute

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 entities.decodeHTMLAttribute in pkg:npm/entities@6.0.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/entities@6.0.1
Demonstrate these symbols/APIs:
  - entities.decodeHTMLAttribute
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:sha256:42486cf22beff0f2ff82d1d9393a1b1a1debfd759e0a4fb8e732354a07c530e5","constraints":{"executionContext":"node"},"contract":["decodeHTMLAttribute decodes standard named entities including \u0026quot;, \u0026apos;, \u0026amp;, \u0026lt;, and \u0026gt;","decodeHTMLAttribute decodes named character entities such as \u0026copy; and \u0026euro;","decodeHTMLAttribute decodes decimal and hexadecimal numeric character references","decodeHTMLAttribute preserves unclosed legacy named entities followed by equals sign or alphanumeric characters","decodeHTMLAttribute decodes unclosed legacy named entities when not followed by equals sign or alphanumeric characters","decodeHTMLAttribute leaves unrecognized entities, lone ampersands, and malformed entity syntax unchanged","decodeHTMLAttribute replaces invalid or surrogate code points with the replacement character"],"goal":"verify entities.decodeHTMLAttribute in pkg:npm/entities@6.0.1","kind":"HOW","packages":["pkg:npm/entities@6.0.1"],"schemaVersion":1,"symbols":["entities.decodeHTMLAttribute"]},"contractCommand":["node","test/contract.js"],"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/entities@6.0.1"],"schemaVersion":1,"subject":"pkg:npm/entities@6.0.1","symbols":["entities.decodeHTMLAttribute"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-entities-decode-html-attribute",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-entities-decode-html-attribute",
      "version": "1.0.0",
      "dependencies": {
        "entities": "6.0.1"
      }
    },
    "node_modules/entities": {
      "version": "6.0.1",
      "resolved": "https://registry.npmjs.org/entities/-/entities-6.0.1.tgz",
      "integrity": "sha512-aN97NXWF6AWBTahfVOIrB/NShkzi5H7F9r1s9mD3cDj4Ko5f2qhhVoYMibXF7GlLveb/D2ioWay8lxI97Ven3g==",
      "license": "BSD-2-Clause",
      "engines": {
        "node": ">=0.12"
      },
      "funding": {
        "url": "https://github.com/fb55/entities?sponsor=1"
      }
    }
  }
}

{
  "name": "sample-entities-decode-html-attribute",
  "version": "1.0.0",
  "private": true,
  "dependencies": {
    "entities": "6.0.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify entities.decodeHTMLAttribute in pkg:npm/entities@6.0.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/entities@6.0.1"
  ],
  "symbols": [
    "entities.decodeHTMLAttribute"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@10.9.8",
    "runtime": "node@22.23.2"
  }
}

const assert = require('node:assert/strict');
const { decodeHTMLAttribute } = require('entities');

// 1. decodeHTMLAttribute decodes standard named entities including ", ', &, <, and >
assert.equal(
  decodeHTMLAttribute('"Hello" & <World> '!'),
  '"Hello" & <World> \'!'
);

// 2. decodeHTMLAttribute decodes named character entities such as &copy; and &euro;
assert.equal(
  decodeHTMLAttribute('&copy; 2026 &euro; 100'),
  '© 2026 € 100'
);

// 3. decodeHTMLAttribute decodes decimal and hexadecimal numeric character references
assert.equal(
  decodeHTMLAttribute('&#65; &#x41; &#X41; &#38; &#x26;'),
  'A A A & &'
);

// 4. decodeHTMLAttribute preserves unclosed legacy named entities followed by equals sign or alphanumeric characters
assert.equal(
  decodeHTMLAttribute('?page=1&amp=2&not=3&notin=4&aring=5'),
  '?page=1&amp=2&not=3&notin=4&aring=5'
);
assert.equal(
  decodeHTMLAttribute('foo&ampbar;baz'),
  'foo&ampbar;baz'
);

// 5. decodeHTMLAttribute decodes unclosed legacy named entities when not followed by equals sign or alphanumeric characters
assert.equal(
  decodeHTMLAttribute('&copy 2026 &not foo'),
  '© 2026 ¬ foo'
);
assert.equal(
  decodeHTMLAttribute('&not'),
  '¬'
);

// 6. decodeHTMLAttribute leaves unrecognized entities, lone ampersands, and malformed entity syntax unchanged
assert.equal(
  decodeHTMLAttribute('&notanentity; & &;'),
  '&notanentity; & &;'
);

// 7. decodeHTMLAttribute replaces invalid or surrogate code points with the replacement character
assert.equal(
  decodeHTMLAttribute('&#0; &#xD800; &#xFFFD;'),
  '\uFFFD \uFFFD \uFFFD'
);

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