ssri 12.0.0: create

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.create 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.create

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:cad8b053b1753a3bc81952c3994eee471be113aeabc1733d6d4bbe748e9a0313","contract":["ssri.create() defaults to sha512, supports chained update(chunk, enc) calls, and returns an Integrity instance from digest()","ssri.create({ algorithms, options }) computes incremental digests across multiple algorithms and attaches option tokens to each Hash","ssri.create({ algorithms, strict: true }) omits non-spec algorithms such as sha1 from the resulting Integrity object"],"goal":"verify ssri.create in pkg:npm/ssri@12.0.0","kind":"HOW","packages":["pkg:npm/ssri@12.0.0"],"schemaVersion":1,"symbols":["ssri.create"]},"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.create"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-ssri-create",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-ssri-create",
      "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-create",
  "version": "1.0.0",
  "private": true,
  "type": "module",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "ssri": "12.0.0"
  }
}

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

import assert from 'node:assert/strict'
import crypto from 'node:crypto'
import * as ssri from 'ssri'

const chunkA = Buffer.from('incremental ')
const chunkB = Buffer.from('integrity ')
const chunkC = Buffer.from('calculation')
const fullBuffer = Buffer.concat([chunkA, chunkB, chunkC])

// 1. Default options: uses sha512 and supports method chaining on update()
const defaultBuilder = ssri.create()
const chainResult = defaultBuilder
  .update(chunkA)
  .update(chunkB.toString('hex'), 'hex')
  .update(chunkC)

assert.equal(chainResult, defaultBuilder)

const defaultIntegrity = defaultBuilder.digest()
assert.equal(defaultIntegrity.isIntegrity, true)
assert.deepEqual(Object.keys(defaultIntegrity), ['sha512'])
assert.equal(defaultIntegrity.sha512.length, 1)

const expectedSha512 = crypto.createHash('sha512').update(fullBuffer).digest('base64')
assert.equal(defaultIntegrity.sha512[0].algorithm, 'sha512')
assert.equal(defaultIntegrity.sha512[0].digest, expectedSha512)
assert.deepEqual(defaultIntegrity.sha512[0].options, [])
assert.equal(defaultIntegrity.toString(), `sha512-${expectedSha512}`)

// 2. Custom algorithms and options: generates Integrity with multiple algorithms and option strings
const multiBuilder = ssri.create({
  algorithms: ['sha256', 'sha384'],
  options: ['optA', 'optB'],
})
multiBuilder.update('incremental ').update('integrity ').update('calculation')
const multiIntegrity = multiBuilder.digest()

const expectedSha256 = crypto.createHash('sha256').update(fullBuffer).digest('base64')
const expectedSha384 = crypto.createHash('sha384').update(fullBuffer).digest('base64')

assert.equal(multiIntegrity.sha256[0].digest, expectedSha256)
assert.deepEqual(multiIntegrity.sha256[0].options, ['optA', 'optB'])
assert.equal(multiIntegrity.sha384[0].digest, expectedSha384)
assert.deepEqual(multiIntegrity.sha384[0].options, ['optA', 'optB'])
assert.equal(
  multiIntegrity.toString(),
  `sha256-${expectedSha256}?optA?optB sha384-${expectedSha384}?optA?optB`
)

// 3. Strict mode filtering: rejects non-spec algorithms when strict: true
const strictBuilder = ssri.create({
  algorithms: ['sha1', 'sha256'],
  strict: true,
})
strictBuilder.update(fullBuffer)
const strictIntegrity = strictBuilder.digest()

assert.equal(strictIntegrity.sha1, undefined)
assert.equal(strictIntegrity.sha256.length, 1)
assert.equal(strictIntegrity.sha256[0].digest, expectedSha256)