read 4.1.0: read

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 read.read in pkg:npm/read@4.1.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/read@4.1.0
Demonstrate these symbols/APIs:
  - read.read

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:sha256:29e3e0d82200ff427bbce6ed973a0616c66a7c8140babc39492bd165223b0374","contract":["read({ prompt, input, output }) writes the trimmed prompt with a trailing space to output and resolves to the line read from input without trailing newline","read({ prompt, default, input, output }) appends '(\u003cdefault\u003e) ' to the prompt and resolves to default.toString() when an empty line is read","read({ prompt, default, silent: true, input, output }) appends '(\u003cdefault hidden\u003e) ' to the prompt instead of exposing the default value","read({ default }) rejects with Error('default value must be string or number') when default is neither undefined, string, nor number","read({ timeout, input, output }) rejects with Error('timed out') when no line arrives before timeout ms"],"goal":"verify read.read in pkg:npm/read@4.1.0","kind":"HOW","packages":["pkg:npm/read@4.1.0"],"schemaVersion":1,"symbols":["read.read"]},"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/read@4.1.0"],"schemaVersion":1,"subject":"pkg:npm/read@4.1.0","symbols":["read.read"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-read-verify",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-read-verify",
      "version": "1.0.0",
      "dependencies": {
        "read": "4.1.0"
      }
    },
    "node_modules/mute-stream": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/mute-stream/-/mute-stream-2.0.0.tgz",
      "integrity": "sha512-WWdIxpyjEn+FhQJQQv9aQAYlHoNVdzIzUySNV1gHUPDSdZJ3yZn7pAAbQcV7B56Mvu881q9FZV+0Vx2xC44VWA==",
      "license": "ISC",
      "engines": {
        "node": "^18.17.0 || >=20.5.0"
      }
    },
    "node_modules/read": {
      "version": "4.1.0",
      "resolved": "https://registry.npmjs.org/read/-/read-4.1.0.tgz",
      "integrity": "sha512-uRfX6K+f+R8OOrYScaM3ixPY4erg69f8DN6pgTvMcA9iRc8iDhwrA4m3Yu8YYKsXJgVvum+m8PkRboZwwuLzYA==",
      "license": "ISC",
      "dependencies": {
        "mute-stream": "^2.0.0"
      },
      "engines": {
        "node": "^18.17.0 || >=20.5.0"
      }
    }
  }
}

{
  "name": "sample-read-verify",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "read": "4.1.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify read.read in pkg:npm/read@4.1.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/read@4.1.0"
  ],
  "symbols": [
    "read.read"
  ]
}

import assert from 'node:assert/strict';
import { PassThrough } from 'node:stream';
import * as readModule from 'read';
import { read } from 'read';

assert.equal(typeof read, 'function');
assert.equal(readModule.read, read);

// 1. Reading a line from custom input/output streams
{
  const input = new PassThrough();
  const output = new PassThrough();
  let capturedOutput = '';
  output.on('data', (chunk) => {
    capturedOutput += chunk.toString('utf8');
  });

  const promise = read({
    prompt: 'Label:',
    input,
    output,
  });

  input.write('item-one\n');
  const result = await promise;
  assert.equal(result, 'item-one');
  assert.equal(capturedOutput, 'Label: ');
}

// 2. Default value fallback on empty line (string and number defaults)
{
  const input = new PassThrough();
  const output = new PassThrough();
  let capturedOutput = '';
  output.on('data', (chunk) => {
    capturedOutput += chunk.toString('utf8');
  });

  const promise = readModule.read({
    prompt: 'Host:',
    default: 'localhost',
    input,
    output,
  });

  input.write('\r\n');
  const result = await promise;
  assert.equal(result, 'localhost');
  assert.equal(capturedOutput, 'Host: (localhost) ');
}

{
  const input = new PassThrough();
  const output = new PassThrough();

  const promise = read({
    prompt: 'Port:',
    default: 8080,
    input,
    output,
  });

  input.write('\n');
  const result = await promise;
  assert.equal(result, '8080');
}

// 3. Silent mode hides default in prompt and mutes echoed characters
{
  const input = new PassThrough();
  const output = new PassThrough();
  let capturedOutput = '';
  output.on('data', (chunk) => {
    capturedOutput += chunk.toString('utf8');
  });

  const promise = read({
    prompt: 'Passphrase:',
    default: 'hidden-val',
    silent: true,
    input,
    output,
  });

  input.write('topsecret\n');
  const result = await promise;
  assert.equal(result, 'topsecret');
  assert.equal(capturedOutput, 'Passphrase: (<default hidden>) ');
}

// 4. Invalid default value type rejects with descriptive error
await assert.rejects(
  () =>
    read({
      default: /** @type {any} */ ({ invalid: true }),
      input: new PassThrough(),
      output: new PassThrough(),
    }),
  {
    name: 'Error',
    message: 'default value must be string or number',
  }
);

// 5. Timeout rejects with 'timed out' when no line is provided in time
await assert.rejects(
  () =>
    read({
      prompt: 'Quick:',
      timeout: 20,
      input: new PassThrough(),
      output: new PassThrough(),
    }),
  {
    name: 'Error',
    message: 'timed out',
  }
);