decompress-response 6.0.0: decompress HTTP response streams (gzip, deflate, brotli)

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: decompress HTTP response streams (gzip, deflate, brotli)
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/decompress-response@6.0.0
Demonstrate these symbols/APIs:
  - decompressResponse

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:sha256:5ef7b84961ad2dc875a5d6c8f4829fbbf8dc0b3f702a9146b0995bd2dbea2842","contract":["decompressResponse transparently decompresses gzip encoded response streams","decompressResponse transparently decompresses deflate encoded response streams","decompressResponse transparently decompresses brotli encoded response streams","decompressResponse returns the stream unmodified for uncompressed responses","decompressResponse preserves response status code and headers via mimic-response"],"goal":"decompress HTTP response streams (gzip, deflate, brotli)","kind":"HOW","packages":["pkg:npm/decompress-response@6.0.0"],"schemaVersion":1,"symbols":["decompressResponse"]},"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/decompress-response@6.0.0"],"schemaVersion":1,"subject":"pkg:npm/decompress-response@6.0.0","symbols":["decompressResponse"],"verifierAdapter":"node-typescript@1"}

{
  "name": "csx-sample-decompress-response",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "csx-sample-decompress-response",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "decompress-response": "6.0.0"
      }
    },
    "node_modules/decompress-response": {
      "version": "6.0.0",
      "resolved": "https://registry.npmjs.org/decompress-response/-/decompress-response-6.0.0.tgz",
      "integrity": "sha512-aW35yZM6Bb/4oJlZncMH2LCoZtJXTRxES17vE3hoRiowU2kWHaJKFkSBDnDR+cm9J+9QhXmREyIfv0pji9ejCQ==",
      "license": "MIT",
      "dependencies": {
        "mimic-response": "^3.1.0"
      },
      "engines": {
        "node": ">=10"
      },
      "funding": {
        "url": "https://github.com/sponsors/sindresorhus"
      }
    },
    "node_modules/mimic-response": {
      "version": "3.1.0",
      "resolved": "https://registry.npmjs.org/mimic-response/-/mimic-response-3.1.0.tgz",
      "integrity": "sha512-z0yWI+4FDrrweS8Zmt4Ej5HdJmky15+L2e6Wgn3+iK5fWzb6T3fhNFq2+MeTRb064c6Wr4N/wv0DzQTjNzHNGQ==",
      "license": "MIT",
      "engines": {
        "node": ">=10"
      },
      "funding": {
        "url": "https://github.com/sponsors/sindresorhus"
      }
    }
  }
}

{
  "name": "csx-sample-decompress-response",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "license": "MIT-0",
  "dependencies": {
    "decompress-response": "6.0.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "decompress HTTP response streams (gzip, deflate, brotli)",
  "kind": "HOW",
  "packages": [
    "pkg:npm/decompress-response@6.0.0"
  ],
  "symbols": [
    "decompressResponse"
  ]
}

import decompressResponse from 'decompress-response';

export function wrapResponse(response) {
  return decompressResponse(response);
}

export async function readDecompressedBody(response) {
  const stream = decompressResponse(response);
  const chunks = [];
  for await (const chunk of stream) {
    chunks.push(typeof chunk === 'string' ? Buffer.from(chunk) : chunk);
  }
  return Buffer.concat(chunks).toString('utf8');
}

import { strict as assert } from 'node:assert';
import http from 'node:http';
import zlib from 'node:zlib';
import { readDecompressedBody, wrapResponse } from '../src/index.mjs';

function startServer() {
  return new Promise((resolve) => {
    const server = http.createServer((req, res) => {
      const url = new URL(req.url, 'http://localhost');
      const type = url.searchParams.get('type');
      const payload = 'Decompressed HTTP response payload test string';

      if (type === 'gzip') {
        res.writeHead(200, { 'content-encoding': 'gzip', 'content-type': 'text/plain' });
        res.end(zlib.gzipSync(Buffer.from(payload)));
      } else if (type === 'deflate') {
        res.writeHead(200, { 'content-encoding': 'deflate', 'content-type': 'text/plain' });
        res.end(zlib.deflateSync(Buffer.from(payload)));
      } else if (type === 'br') {
        res.writeHead(200, { 'content-encoding': 'br', 'content-type': 'text/plain' });
        res.end(zlib.brotliCompressSync(Buffer.from(payload)));
      } else if (type === 'none') {
        res.writeHead(200, { 'content-type': 'text/plain' });
        res.end(payload);
      } else if (type === 'empty') {
        res.writeHead(204);
        res.end();
      }
    });

    server.listen(0, '127.0.0.1', () => {
      const port = server.address().port;
      resolve({ server, port });
    });
  });
}

const { server, port } = await startServer();
const expected = 'Decompressed HTTP response payload test string';

function request(path) {
  return new Promise((resolve, reject) => {
    http.get(`http://localhost:${port}${path}`, resolve).on('error', reject);
  });
}

try {
  // Contract 1: decompressResponse transparently decompresses gzip encoded response streams
  {
    const res = await request('/?type=gzip');
    const body = await readDecompressedBody(res);
    assert.equal(body, expected);
  }

  // Contract 2: decompressResponse transparently decompresses deflate encoded response streams
  {
    const res = await request('/?type=deflate');
    const body = await readDecompressedBody(res);
    assert.equal(body, expected);
  }

  // Contract 3: decompressResponse transparently decompresses brotli encoded response streams
  {
    const res = await request('/?type=br');
    const body = await readDecompressedBody(res);
    assert.equal(body, expected);
  }

  // Contract 4: decompressResponse returns the stream unmodified for uncompressed responses
  {
    const res = await request('/?type=none');
    const wrapped = wrapResponse(res);
    assert.equal(wrapped, res);
    const body = await readDecompressedBody(res);
    assert.equal(body, expected);
  }

  // Contract 5: decompressResponse preserves response status code and headers via mimic-response
  {
    const res = await request('/?type=gzip');
    const wrapped = wrapResponse(res);
    assert.equal(wrapped.statusCode, 200);
    assert.equal(wrapped.headers['content-encoding'], 'gzip');
    assert.equal(wrapped.headers['content-type'], 'text/plain');
  }

  console.log('CONTRACT PASS: decompressResponse successfully verified');
} finally {
  server.close();
}