Using jsonld as a factory rather than a singleton

jsonld-factory.js

const JSONLD = require('jsonld')

const jsonld = JSONLD // try commenting this line
// const jsonld = JSONLD() // and uncommenting this one

const DefaultClaimContext = {
  cred: 'https://w3id.org/credentials#',
  schema: 'http://schema.org/',
  sec: 'https://w3id.org/security#',

  issuer: 'cred:issuer',
  issuanceDate: 'cred:issued',
  type: 'http://schema.org/additionalType',
  claim: 'http://schema.org/Thing', // The most generic definition in schema.org,
}

const DefaultWorkClaimContext = {
  author: 'schema:author',
  claim: 'http://schema.org/CreativeWork',
  dateCreated: 'schema:dateCreated',
  datePublished: 'schema:datePublished',
  name: 'schema:name',
  keywords: 'schema:keywords',
  archiveUrl: 'schema:url',
  hash: 'sec:digestValue',
}

const DefaultIdentityClaimContext = {
  publicKey: 'sec:publicKeyBase58',
  profileUrl: 'sec:owner',
}

const canonizeClaim = async (document) => {
  const contextualClaim = {
    '@context': {
      ...DefaultClaimContext,
      ...claimTypeDefaults[document.type],
      ...document['@context'],
    },
    type: document.type,
    issuer: document.issuer,
    issuanceDate: document.issuanceDate,
    claim: document.claim,
  }
  return jsonld.canonize(contextualClaim)
}

const claimTypeDefaults = {
  Work: DefaultWorkClaimContext,
  Identity: DefaultIdentityClaimContext,
}

const testPublicKeyEd25519Base58 = 'JAi9YoyDdgBQLenyVzoXWH4C26wKMzHrjertxVrjLWTe'

const testOwnerUrl = `data:,${testPublicKeyEd25519Base58}`

const DataParser = jsonld => {
  const nodeDocumentLoader = jsonld.documentLoaders.node({ usePromise: true })

  const customLoader = async (url, callback) => {
    const parsedData = ParseDataUrl(url)
    if (parsedData) {
      const publicKey = {
        id: url,
        type: 'Ed25519VerificationKey2018',
        owner: url,
        publicKeyBase58: parsedData.data,
      }
      return callback(null, {
        contextUrl: ['https://w3id.org/security/v2'],
        document: {
          owner: {
            id: url,
            publicKey: [publicKey],
          },
          publicKey,
        },
      })
    }
    nodeDocumentLoader(url, callback)
  }

  jsonld.documentLoader = customLoader
}

DataParser(jsonld)

const TheRaven = {
  id: '996efc4bd089f62e596f3c2c15bda3002d45540481df3be2c11192a6963ee8a7',
  type: 'Work',
  issuer: testOwnerUrl,
  issuanceDate: '2017-11-13T15:00:00.000Z',
  claim: {
    name: 'The Raven',
    author: 'Edgar Allan Poe',
    keywords: 'poem',
    dateCreated: '',
    datePublished: '1845-01-29T03:00:00.000Z',
    hash: 'de1c818f9be211a78dff90a03b9e297bbb61b3c292f1c1bbc3a5283e9b203cb1',
    archiveUrl: 'ipfs:/theRaven',
  },
  'https://w3id.org/security#proof': {
    '@graph': {
      '@type': 'https://w3id.org/security#Ed25519Signature2018',
      created: {
        '@type': 'http://www.w3.org/2001/XMLSchema#dateTime',
        '@value': '2018-09-05T20:19:20Z',
      },
      'http://purl.org/dc/terms/creator': {
        '@id': testOwnerUrl,
      },
      'https://w3id.org/security#jws':
        'eyJhbGciOiJFZERTQSIsImI2NCI6ZmFsc2UsImNyaXQiOlsiYjY0Il19..TSHkMOwbWZvIp8Hd-MyebaMgItf4Iyl3dgUSlHBBlnidw' +
        'gzo084pGpKmbOewYFrXfmAVhXnC4UPzaPUjaU9BDw',
    },
  },
}

async function main(claim) {
  console.log('claim', claim)
  const canonizedClaim = await canonizeClaim(claim)
  console.log('canonizedClaim', canonizedClaim)
}


main(TheRaven).catch(console.error)

/*********

In both cases the output is:

$ node index.js 
claim { id:
   '996efc4bd089f62e596f3c2c15bda3002d45540481df3be2c11192a6963ee8a7',
  type: 'Work',
  issuer: 'data:,JAi9YoyDdgBQLenyVzoXWH4C26wKMzHrjertxVrjLWTe',
  issuanceDate: '2017-11-13T15:00:00.000Z',
  claim:
   { name: 'The Raven',
     author: 'Edgar Allan Poe',
     keywords: 'poem',
     dateCreated: '',
     datePublished: '1845-01-29T03:00:00.000Z',
     hash:
      'de1c818f9be211a78dff90a03b9e297bbb61b3c292f1c1bbc3a5283e9b203cb1',
     archiveUrl: 'ipfs:/theRaven' },
  'https://w3id.org/security#proof':
   { '@graph':
      { '@type': 'https://w3id.org/security#Ed25519Signature2018',
        created: [Object],
        'http://purl.org/dc/terms/creator': [Object],
        'https://w3id.org/security#jws':
         'eyJhbGciOiJFZERTQSIsImI2NCI6ZmFsc2UsImNyaXQiOlsiYjY0Il19..TSHkMOwbWZvIp8Hd-MyebaMgItf4Iyl3dgUSlHBBlnidwgzo084pGpKmbOewYFrXfmAVhXnC4UPzaPUjaU9BDw' } } }
canonizedClaim _:c14n0 <http://schema.org/CreativeWork> _:c14n1 .
_:c14n0 <http://schema.org/additionalType> "Work" .
_:c14n0 <https://w3id.org/credentials#issued> "2017-11-13T15:00:00.000Z" .
_:c14n0 <https://w3id.org/credentials#issuer> "data:,JAi9YoyDdgBQLenyVzoXWH4C26wKMzHrjertxVrjLWTe" .
_:c14n1 <http://schema.org/author> "Edgar Allan Poe" .
_:c14n1 <http://schema.org/dateCreated> "" .
_:c14n1 <http://schema.org/datePublished> "1845-01-29T03:00:00.000Z" .
_:c14n1 <http://schema.org/keywords> "poem" .
_:c14n1 <http://schema.org/name> "The Raven" .
_:c14n1 <http://schema.org/url> "ipfs:/theRaven" .
_:c14n1 <https://w3id.org/security#digestValue> "de1c818f9be211a78dff90a03b9e297bbb61b3c292f1c1bbc3a5283e9b203cb1" .

$ node index.js 
claim { id:
   '996efc4bd089f62e596f3c2c15bda3002d45540481df3be2c11192a6963ee8a7',
  type: 'Work',
  issuer: 'data:,JAi9YoyDdgBQLenyVzoXWH4C26wKMzHrjertxVrjLWTe',
  issuanceDate: '2017-11-13T15:00:00.000Z',
  claim:
   { name: 'The Raven',
     author: 'Edgar Allan Poe',
     keywords: 'poem',
     dateCreated: '',
     datePublished: '1845-01-29T03:00:00.000Z',
     hash:
      'de1c818f9be211a78dff90a03b9e297bbb61b3c292f1c1bbc3a5283e9b203cb1',
     archiveUrl: 'ipfs:/theRaven' },
  'https://w3id.org/security#proof':
   { '@graph':
      { '@type': 'https://w3id.org/security#Ed25519Signature2018',
        created: [Object],
        'http://purl.org/dc/terms/creator': [Object],
        'https://w3id.org/security#jws':
         'eyJhbGciOiJFZERTQSIsImI2NCI6ZmFsc2UsImNyaXQiOlsiYjY0Il19..TSHkMOwbWZvIp8Hd-MyebaMgItf4Iyl3dgUSlHBBlnidwgzo084pGpKmbOewYFrXfmAVhXnC4UPzaPUjaU9BDw' } } }
canonizedClaim _:c14n0 <http://schema.org/CreativeWork> _:c14n1 .
_:c14n0 <http://schema.org/additionalType> "Work" .
_:c14n0 <https://w3id.org/credentials#issued> "2017-11-13T15:00:00.000Z" .
_:c14n0 <https://w3id.org/credentials#issuer> "data:,JAi9YoyDdgBQLenyVzoXWH4C26wKMzHrjertxVrjLWTe" .
_:c14n1 <http://schema.org/author> "Edgar Allan Poe" .
_:c14n1 <http://schema.org/dateCreated> "" .
_:c14n1 <http://schema.org/datePublished> "1845-01-29T03:00:00.000Z" .
_:c14n1 <http://schema.org/keywords> "poem" .
_:c14n1 <http://schema.org/name> "The Raven" .
_:c14n1 <http://schema.org/url> "ipfs:/theRaven" .
_:c14n1 <https://w3id.org/security#digestValue> "de1c818f9be211a78dff90a03b9e297bbb61b3c292f1c1bbc3a5283e9b203cb1" .

The two outputs are identical, so it seems to be working.

*****************/