ssri 12.0.0: checkStream

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 ssri.checkStream in pkg:npm/ssri@12.0.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/ssri@12.0.0
Demonstrate these symbols/APIs:
  - ssri.checkStream

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:sha256:382471f426c9497ec684742f54850a8cbb20707e15f47b7b682013975aa82a41","contract":["ssri.checkStream resolves to the matching Hash object when a readable stream matches the Integrity object and expected byte size","ssri.checkStream accepts an SRI string and honors custom pickAlgorithm selection across multi-algorithm metadata","ssri.checkStream rejects with code EINTEGRITY when the streamed bytes do not match the expected digest","ssri.checkStream rejects with code EBADSIZE (including expected and found byte counts) when the stream length differs from opts.size"],"goal":"verify ssri.checkStream in pkg:npm/ssri@12.0.0","kind":"HOW","packages":["pkg:npm/ssri@12.0.0"],"schemaVersion":1,"symbols":["ssri.checkStream"]},"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/ssri@12.0.0"],"schemaVersion":1,"subject":"pkg:npm/ssri@12.0.0","symbols":["ssri.checkStream"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-ssri-checkstream",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-ssri-checkstream",
      "version": "1.0.0",
      "dependencies": {
        "ssri": "12.0.0"
      }
    },
    "node_modules/minipass": {
      "version": "7.1.3",
      "resolved": "https://registry.npmjs.org/minipass/-/minipass-7.1.3.tgz",
      "integrity": "sha512-tEBHqDnIoM/1rXME1zgka9g6Q2lcoCkxHLuc7ODJ5BxbP5d4c2Z5cGgtXAku59200Cx7diuHTOYfSBD8n6mm8A==",
      "license": "BlueOak-1.0.0",
      "engines": {
        "node": ">=16 || 14 >=14.17"
      }
    },
    "node_modules/ssri": {
      "version": "12.0.0",
      "resolved": "https://registry.npmjs.org/ssri/-/ssri-12.0.0.tgz",
      "integrity": "sha512-S7iGNosepx9RadX82oimUkvr0Ct7IjJbEbs4mJcTxst8um95J3sDYU1RBEOvdu6oL1Wek2ODI5i4MAw+dZ6cAQ==",
      "license": "ISC",
      "dependencies": {
        "minipass": "^7.0.3"
      },
      "engines": {
        "node": "^18.17.0 || >=20.5.0"
      }
    }
  }
}

{
  "name": "sample-ssri-checkstream",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "ssri": "12.0.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify ssri.checkStream in pkg:npm/ssri@12.0.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/ssri@12.0.0"
  ],
  "symbols": [
    "ssri.checkStream"
  ]
}

import assert from 'node:assert/strict'
import { Readable } from 'node:stream'
import * as ssri from 'ssri'

const chunks = [Buffer.from('streamed '), Buffer.from('integrity '), Buffer.from('payload')]
const fullData = Buffer.concat(chunks)

const integrity = ssri.fromData(fullData, {
  algorithms: ['sha256', 'sha512'],
})

// 1. Verify stream against Integrity object and exact size
const matched = await ssri.checkStream(
  Readable.from(chunks),
  integrity,
  { size: fullData.length }
)
assert.equal(matched.isHash, true)
assert.equal(matched.algorithm, 'sha512')
assert.equal(matched.digest, integrity.sha512[0].digest)

// 2. Verify stream against an SRI string and custom pickAlgorithm
const picked = await ssri.checkStream(
  Readable.from(chunks),
  integrity.toString(),
  { pickAlgorithm: () => 'sha256' }
)
assert.equal(picked.isHash, true)
assert.equal(picked.algorithm, 'sha256')
assert.equal(picked.digest, integrity.sha256[0].digest)

// 3. Reject with EINTEGRITY when stream data does not match digest
await assert.rejects(
  ssri.checkStream(Readable.from([Buffer.from('tampered payload')]), integrity),
  { code: 'EINTEGRITY' }
)

// 4. Reject with EBADSIZE when stream length mismatches expected size
await assert.rejects(
  ssri.checkStream(Readable.from(chunks), integrity, { size: fullData.length + 5 }),
  {
    code: 'EBADSIZE',
    expected: fullData.length + 5,
    found: fullData.length,
  }
)