@web3-storage/content-claims/src/server/service/assert.js

Implementation of the Content Claims Protocol.

import * as Server from '@ucanto/server'
import * as Digest from 'multiformats/hashes/digest'
import * as Assert from '../../capability/assert.js'

/**
 * @param {import('./api.js').AssertServiceContext} context
 * @returns {import('./api.js').AssertService}
 */
export function createService (context) {
  return {
    inclusion: Server.provide(Assert.inclusion, input => handler(input, context)),
    index: Server.provide(Assert.index, input => handler(input, context)),
    location: Server.provide(Assert.location, input => handler(input, context)),
    partition: Server.provide(Assert.partition, input => handler(input, context)),
    relation: Server.provide(Assert.relation, input => handler(input, context)),
    equals: Server.provide(Assert.equals, input => handler(input, context))
  }
}

/**
 * @param {object} config
 * @param {import('./api.js').AnyAssertCap} config.capability
 * @param {import('@ucanto/interface').Invocation} config.invocation
 * @param {import('./api.js').AssertServiceContext} context
 * @returns {Promise<import('@ucanto/server').Result<{}, import('@ucanto/server').Failure>>}
 */
export const handler = async ({ capability, invocation }, { claimStore }) => {
  const { content } = capability.nb
  const archive = await invocation.archive()
  if (archive.error) throw new Error('failed invocation archive', { cause: archive.error })
  const claim = {
    claim: invocation.cid,
    bytes: archive.ok,
    content: 'digest' in content
      ? Digest.decode(content.digest)
      : content.multihash,
    expiration: invocation.expiration,
    value: capability
  }
  await claimStore.put(claim)
  return { ok: {} }
}