degenerator 5.0.1

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/degenerator@5.0.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/degenerator@5.0.1

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:sha256:7dfeae59a38e18916497309c1cf32305de4e84fd87b08e0c64f9c5391c43c589","contract":["degenerator converts synchronous function calling specified function to async function with await expression","degenerator leaves synchronous functions unchanged when no matching functions are called","degenerator matches function names using regular expression patterns","degenerator cascades async conversion to caller functions when a called function becomes async","degenerator tracks variable alias assignments and injects await for calls via aliased names","degenerator supports member expression call targets such as object method invocations","degenerator throws TypeError when names argument is not an array","transformed code executes asynchronously and resolves awaited promise return value"],"goal":"verify pkg:npm/degenerator@5.0.1","kind":"HOW","packages":["pkg:npm/degenerator@5.0.1"],"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/degenerator@5.0.1"],"schemaVersion":1,"subject":"pkg:npm/degenerator@5.0.1","verifierAdapter":"node-typescript@1"}

{
  "name": "sample-degenerator",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-degenerator",
      "version": "1.0.0",
      "dependencies": {
        "degenerator": "5.0.1"
      }
    },
    "node_modules/ast-types": {
      "version": "0.13.4",
      "resolved": "https://registry.npmjs.org/ast-types/-/ast-types-0.13.4.tgz",
      "integrity": "sha512-x1FCFnFifvYDDzTaLII71vG5uvDwgtmDTEVWAxrgeiR8VjMONcCXJx7E+USjDtHlwFmt9MysbqgF9b9Vjr6w+w==",
      "license": "MIT",
      "dependencies": {
        "tslib": "^2.0.1"
      },
      "engines": {
        "node": ">=4"
      }
    },
    "node_modules/degenerator": {
      "version": "5.0.1",
      "resolved": "https://registry.npmjs.org/degenerator/-/degenerator-5.0.1.tgz",
      "integrity": "sha512-TllpMR/t0M5sqCXfj85i4XaAzxmS5tVA16dqvdkMwGmzI+dXLXnw3J+3Vdv7VKw+ThlTMboK6i9rnZ6Nntj5CQ==",
      "license": "MIT",
      "dependencies": {
        "ast-types": "^0.13.4",
        "escodegen": "^2.1.0",
        "esprima": "^4.0.1"
      },
      "engines": {
        "node": ">= 14"
      }
    },
    "node_modules/escodegen": {
      "version": "2.1.0",
      "resolved": "https://registry.npmjs.org/escodegen/-/escodegen-2.1.0.tgz",
      "integrity": "sha512-2NlIDTwUWJN0mRPQOdtQBzbUHvdGY2P1VXSyU83Q3xKxM7WHX2Ql8dKq782Q9TgQUNOLEzEYu9bzLNj1q88I5w==",
      "license": "BSD-2-Clause",
      "dependencies": {
        "esprima": "^4.0.1",
        "estraverse": "^5.2.0",
        "esutils": "^2.0.2"
      },
      "bin": {
        "escodegen": "bin/escodegen.js",
        "esgenerate": "bin/esgenerate.js"
      },
      "engines": {
        "node": ">=6.0"
      },
      "optionalDependencies": {
        "source-map": "~0.6.1"
      }
    },
    "node_modules/esprima": {
      "version": "4.0.1",
      "resolved": "https://registry.npmjs.org/esprima/-/esprima-4.0.1.tgz",
      "integrity": "sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==",
      "license": "BSD-2-Clause",
      "bin": {
        "esparse": "bin/esparse.js",
        "esvalidate": "bin/esvalidate.js"
      },
      "engines": {
        "node": ">=4"
      }
    },
    "node_modules/estraverse": {
      "version": "5.3.0",
      "resolved": "https://registry.npmjs.org/estraverse/-/estraverse-5.3.0.tgz",
      "integrity": "sha512-MMdARuVEQziNTeJD8DgMqmhwR11BRQ/cBP+pLtYdSTnf3MIO8fFeiINEbX36ZdNlfU/7A9f3gUw49B3oQsvwBA==",
      "license": "BSD-2-Clause",
      "engines": {
        "node": ">=4.0"
      }
    },
    "node_modules/esutils": {
      "version": "2.0.3",
      "resolved": "https://registry.npmjs.org/esutils/-/esutils-2.0.3.tgz",
      "integrity": "sha512-kVscqXk4OCp68SZ0dkgEKVi6/8ij300KBWTJq32P/dYeWTSwK41WyTxalN1eRmA5Z9UU/LX9D7FWSmV9SAYx6g==",
      "license": "BSD-2-Clause",
      "engines": {
        "node": ">=0.10.0"
      }
    },
    "node_modules/source-map": {
      "version": "0.6.1",
      "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
      "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
      "license": "BSD-3-Clause",
      "optional": true,
      "engines": {
        "node": ">=0.10.0"
      }
    },
    "node_modules/tslib": {
      "version": "2.8.1",
      "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.8.1.tgz",
      "integrity": "sha512-oJFu94HQb+KVduSUQL7wnpmqnfmLsOA/nAh6b6EH0wCEoK0/mPeXU6c3wKDV83MkOuHPRHtSXKKU99IBazS/2w==",
      "license": "0BSD"
    }
  }
}

{
  "name": "sample-degenerator",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "dependencies": {
    "degenerator": "5.0.1"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/degenerator@5.0.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/degenerator@5.0.1"
  ]
}

import assert from 'node:assert/strict';
import { degenerator } from 'degenerator';

// 1. degenerator converts synchronous function calling specified function to async function with await expression
{
  const input = 'function loadData() { const res = fetch("https://example.com"); return res; }';
  const output = degenerator(input, ['fetch']);
  assert.match(output, /async function loadData\(\)/);
  assert.match(output, /await fetch\(['"]https:\/\/example\.com['"]\)/);
}

// 2. degenerator leaves synchronous functions unchanged when no matching functions are called
{
  const input = 'function computeTotal(a, b) { return a + b; }';
  const output = degenerator(input, ['fetch']);
  assert.ok(!output.includes('async'));
  assert.ok(!output.includes('await'));
  assert.match(output, /function computeTotal\(a, b\)/);
}

// 3. degenerator matches function names using regular expression patterns
{
  const input = 'function run() { return getProfile() + fetchFeed(); }';
  const output = degenerator(input, [/^get/, /^fetch/]);
  assert.match(output, /async function run\(\)/);
  assert.match(output, /await getProfile\(\)/);
  assert.match(output, /await fetchFeed\(\)/);
}

// 4. degenerator cascades async conversion to caller functions when a called function becomes async
{
  const input = 'function inner() { return fetch(); }\nfunction outer() { return inner(); }';
  const output = degenerator(input, ['fetch']);
  assert.match(output, /async function inner\(\)/);
  assert.match(output, /async function outer\(\)/);
  assert.match(output, /await inner\(\)/);
}

// 5. degenerator tracks variable alias assignments and injects await for calls via aliased names
{
  const input = 'const request = fetch;\nfunction handler() { return request(); }';
  const output = degenerator(input, ['fetch']);
  assert.match(output, /async function handler\(\)/);
  assert.match(output, /await request\(\)/);
}

// 6. degenerator supports member expression call targets such as object method invocations
{
  const input = 'function resolveHost() { return dns.lookup("localhost"); }';
  const output = degenerator(input, ['dns.lookup']);
  assert.match(output, /async function resolveHost\(\)/);
  assert.match(output, /await dns\.lookup\(['"]localhost['"]\)/);
}

// 7. degenerator throws TypeError when names argument is not an array
{
  assert.throws(
    () => degenerator('function fn() {}', null),
    {
      name: 'TypeError',
      message: 'an array of async function "names" is required'
    }
  );
}

// 8. transformed code executes asynchronously and resolves awaited promise return value
{
  const code = degenerator('function getAnswer() { return queryDatabase(); }', ['queryDatabase']);
  const queryDatabase = () => Promise.resolve(42);
  const fn = new Function('queryDatabase', 'return (' + code + ')()')(queryDatabase);
  const result = await fn;
  assert.equal(result, 42);
}