ssri 12.0.0: stringify

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.stringify 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.stringify

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:sha256:1eebb8a3121b2e5eeb091e4849556f1af2af869ae55767ac71e850c6d5cce3c5","contract":["ssri.stringify serializes multi-algorithm Integrity objects with hash options and custom sep delimiter","ssri.stringify serializes individual Hash instances and normalizes raw SRI strings","ssri.stringify round-trips cleanly with ssri.parse and ssri.fromData"],"goal":"verify ssri.stringify in pkg:npm/ssri@12.0.0","kind":"HOW","packages":["pkg:npm/ssri@12.0.0"],"schemaVersion":1,"symbols":["ssri.stringify"]},"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.stringify"],"verifierAdapter":"node-typescript@1"}

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

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

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

const payload = Buffer.from('ssri stringify contract payload')

// 1. Stringify multi-algorithm Integrity object with options and custom separator
const integrity = ssri.fromData(payload, {
  algorithms: ['sha256', 'sha512'],
  options: ['optA', 'optB'],
})

const defaultStr = ssri.stringify(integrity)
assert.match(
  defaultStr,
  /^sha256-[A-Za-z0-9+/=]+\?optA\?optB sha512-[A-Za-z0-9+/=]+\?optA\?optB$/
)

const customSepStr = ssri.stringify(integrity, { sep: '\n' })
assert.equal(customSepStr, defaultStr.replace(' ', '\n'))

// 2. Stringify a single Hash object
const singleHash = integrity.sha256[0]
const singleStr = ssri.stringify(singleHash)
assert.equal(singleStr, singleHash.toString())
assert.match(singleStr, /^sha256-[A-Za-z0-9+/=]+\?optA\?optB$/)

// 3. Stringify an existing SRI string (normalizing whitespace and strict mode)
const messySri = `   ${singleStr}    ${integrity.sha512[0].toString()}   `
assert.equal(ssri.stringify(messySri), defaultStr)
assert.equal(ssri.stringify(messySri, { sep: ' | ' }), defaultStr.replace(' ', ' | '))

// 4. Round-trip equivalence with ssri.parse
const reparsed = ssri.parse(defaultStr)
assert.equal(ssri.stringify(reparsed), defaultStr)