ansi-escapes 4.3.2: ansiEscapes.cursorMove, ansiEscapes.cursorTo, ansiEscapes.eraseScreen

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/ansi-escapes@4.3.2
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/ansi-escapes@4.3.2
Demonstrate these symbols/APIs:
  - ansiEscapes.cursorMove
  - ansiEscapes.cursorTo
  - ansiEscapes.eraseScreen

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:sha256:0b394e43d33274115df2006abc1e370cfad4ca1fb33edb614463957bf5d9f4b3","contract":["cursorTo moves cursor to absolute column x or position (x, y)","cursorTo throws TypeError when x is not a number","cursorMove produces relative cursor movement escape sequences for horizontal and vertical offsets","cursorMove throws TypeError when x is not a number","eraseScreen provides the ANSI escape code to erase the entire screen"],"goal":"verify pkg:npm/ansi-escapes@4.3.2","kind":"HOW","packages":["pkg:npm/ansi-escapes@4.3.2"],"schemaVersion":1,"symbols":["ansiEscapes.cursorMove","ansiEscapes.cursorTo","ansiEscapes.eraseScreen"]},"contractCommand":["node","test/contract.js"],"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/ansi-escapes@4.3.2"],"schemaVersion":1,"subject":"pkg:npm/ansi-escapes@4.3.2","symbols":["ansiEscapes.cursorMove","ansiEscapes.cursorTo","ansiEscapes.eraseScreen"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-ansi-escapes",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-ansi-escapes",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "ansi-escapes": "4.3.2"
      }
    },
    "node_modules/ansi-escapes": {
      "version": "4.3.2",
      "resolved": "https://registry.npmjs.org/ansi-escapes/-/ansi-escapes-4.3.2.tgz",
      "integrity": "sha512-gKXj5ALrKWQLsYG9jlTRmR/xKluxHV+Z9QEwNIgCfM1/uwPMCuzVVnh5mwTd+OuBZcwSIMbqssNWRm1lE51QaQ==",
      "license": "MIT",
      "dependencies": {
        "type-fest": "^0.21.3"
      },
      "engines": {
        "node": ">=8"
      },
      "funding": {
        "url": "https://github.com/sponsors/sindresorhus"
      }
    },
    "node_modules/type-fest": {
      "version": "0.21.3",
      "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-0.21.3.tgz",
      "integrity": "sha512-t0rzBq87m3fVcduHDUFhKmyyX+9eo6WQjZvf51Ea/M0Q7+T374Jp1aUiyUl0GKxp8M/OETVHSDvmkyPgvX+X2w==",
      "license": "(MIT OR CC0-1.0)",
      "engines": {
        "node": ">=10"
      },
      "funding": {
        "url": "https://github.com/sponsors/sindresorhus"
      }
    }
  }
}

{
  "name": "sample-ansi-escapes",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification for ansi-escapes cursor positioning and screen clearing",
  "main": "src/index.js",
  "scripts": {
    "test": "node test/contract.js"
  },
  "dependencies": {
    "ansi-escapes": "4.3.2"
  },
  "license": "MIT-0"
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/ansi-escapes@4.3.2",
  "kind": "HOW",
  "packages": [
    "pkg:npm/ansi-escapes@4.3.2"
  ],
  "symbols": [
    "ansiEscapes.cursorMove",
    "ansiEscapes.cursorTo",
    "ansiEscapes.eraseScreen"
  ]
}

const ansiEscapesModule = require('ansi-escapes');

const ansiEscapes = ansiEscapesModule.default || ansiEscapesModule;
const { cursorTo, cursorMove, eraseScreen } = ansiEscapes;

/**
 * Moves cursor to absolute column x or position (x, y).
 * @param {number} x - 0-based column coordinate
 * @param {number} [y] - 0-based row coordinate
 * @returns {string} ANSI escape sequence
 */
function moveTo(x, y) {
  return cursorTo(x, y);
}

/**
 * Moves cursor relative to current position by x columns and y rows.
 * @param {number} x - horizontal relative offset
 * @param {number} [y] - vertical relative offset
 * @returns {string} ANSI escape sequence
 */
function moveCursor(x, y) {
  return cursorMove(x, y);
}

/**
 * Erases the entire screen.
 * @returns {string} ANSI escape sequence
 */
function getEraseScreenCode() {
  return eraseScreen;
}

/**
 * Positions cursor and writes text.
 * @param {number} x
 * @param {number} y
 * @param {string} text
 * @returns {string}
 */
function renderAt(x, y, text) {
  return `${cursorTo(x, y)}${text}`;
}

/**
 * Erases screen, positions cursor, and writes text.
 * @param {number} x
 * @param {number} y
 * @param {string} text
 * @returns {string}
 */
function clearAndRender(x, y, text) {
  return `${eraseScreen}${cursorTo(x, y)}${text}`;
}

module.exports = {
  ansiEscapes,
  cursorTo,
  cursorMove,
  eraseScreen,
  moveTo,
  moveCursor,
  getEraseScreenCode,
  renderAt,
  clearAndRender,
};

const assert = require('node:assert');
const {
  ansiEscapes,
  cursorTo,
  cursorMove,
  eraseScreen,
  moveTo,
  moveCursor,
  getEraseScreenCode,
  renderAt,
  clearAndRender,
} = require('../src/index.js');

// 1. cursorTo moves cursor to absolute column x or position (x, y)
assert.strictEqual(typeof cursorTo, 'function', 'cursorTo must be a function');
assert.strictEqual(cursorTo(0), '\u001B[1G');
assert.strictEqual(cursorTo(5), '\u001B[6G');
assert.strictEqual(cursorTo(0, 0), '\u001B[1;1H');
assert.strictEqual(cursorTo(10, 20), '\u001B[21;11H');
assert.strictEqual(moveTo(5), '\u001B[6G');
assert.strictEqual(moveTo(10, 20), '\u001B[21;11H');
assert.strictEqual(renderAt(4, 2, 'hello'), '\u001B[3;5Hhello');

// 2. cursorTo throws TypeError when x is not a number
assert.throws(() => {
  cursorTo();
}, {
  name: 'TypeError',
  message: 'The `x` argument is required',
});
assert.throws(() => {
  cursorTo(undefined, 5);
}, {
  name: 'TypeError',
  message: 'The `x` argument is required',
});
assert.throws(() => {
  cursorTo('10');
}, {
  name: 'TypeError',
  message: 'The `x` argument is required',
});

// 3. cursorMove produces relative cursor movement escape sequences for horizontal and vertical offsets
assert.strictEqual(typeof cursorMove, 'function', 'cursorMove must be a function');
assert.strictEqual(cursorMove(0, 0), '');
assert.strictEqual(cursorMove(5, 0), '\u001B[5C');
assert.strictEqual(cursorMove(-3, 0), '\u001B[3D');
assert.strictEqual(cursorMove(0, 4), '\u001B[4B');
assert.strictEqual(cursorMove(0, -2), '\u001B[2A');
assert.strictEqual(cursorMove(2, 3), '\u001B[2C\u001B[3B');
assert.strictEqual(cursorMove(-1, -4), '\u001B[1D\u001B[4A');
assert.strictEqual(cursorMove(3), '\u001B[3C');
assert.strictEqual(moveCursor(2, 3), '\u001B[2C\u001B[3B');

// 4. cursorMove throws TypeError when x is not a number
assert.throws(() => {
  cursorMove();
}, {
  name: 'TypeError',
  message: 'The `x` argument is required',
});
assert.throws(() => {
  cursorMove('5');
}, {
  name: 'TypeError',
  message: 'The `x` argument is required',
});

// 5. eraseScreen provides the ANSI escape code to erase the entire screen
assert.strictEqual(typeof eraseScreen, 'string', 'eraseScreen must be a string');
assert.strictEqual(eraseScreen, '\u001B[2J');
assert.strictEqual(getEraseScreenCode(), '\u001B[2J');
assert.strictEqual(clearAndRender(0, 0, 'ready'), '\u001B[2J\u001B[1;1Hready');

console.log('All contract assertions passed successfully.');