pgh-sidecar / test / overlay-mirror.test.js

import test from 'brittle'
import fs from '#node:fs'
import path from '#node:path'
import { mkdtempSync, writeFileSync, mkdirSync } from '#node:fs'
import { tmpdir } from '#node:os'

import { parsePointer, selectMissingOids, discoverMirrorTargets, runOverlayMirror } from '../lib/overlay-mirror.js'

const deps = { fs, path }
const OID = 'a'.repeat(64)
const OID2 = 'b'.repeat(64)

test('parsePointer reads a hyper-overlay v1 pointer (strips blake2b: prefix)', (t) => {
  const p = parsePointer('hyper-overlay v1\noid blake2b:' + OID + '\nsize 5878386\n')
  t.alike(p, { oid: OID, size: 5878386 }, 'parsed oid + size')
  t.alike(parsePointer('hyper-overlay v1\noid ' + OID + '\nsize 10'), { oid: OID, size: 10 }, 'oid without prefix also accepted')
  t.is(parsePointer('\x00\x01 binary png bytes'), null, 'real binary (not a pointer) → null')
  t.is(parsePointer('hyper-overlay v1\n'), null, 'magic but no oid → null')
})

test('selectMissingOids dedups + skips oids already present in the spool', (t) => {
  const spool = mkdtempSync(path.join(tmpdir(), 'om-spool-'))
  writeFileSync(path.join(spool, OID), 'already here')
  const pointers = [
    { path: 'a.png', oid: OID, size: 1 },   // present → skip
    { path: 'b.png', oid: OID2, size: 2 },  // missing → keep
    { path: 'c.png', oid: OID2, size: 2 }   // dup of b → skip
  ]
  const missing = selectMissingOids(pointers, spool, deps)
  t.is(missing.length, 1, 'only the one missing, de-duplicated')
  t.is(missing[0].oid, OID2, 'the missing oid')
})

test('discoverMirrorTargets keeps repos published elsewhere, skips own + non-overlay', async (t) => {
  const self = 'd'.repeat(64)
  const other = 'e'.repeat(64)
  const cfgs = {
    'hyper-tps': { peerServerKey: other }, // published elsewhere → mirror it
    'my-app': { peerServerKey: self },     // we publish it → skip
    'plain-repo': null                     // no overlay.json → skip
  }
  const targets = await discoverMirrorTargets({
    repos: ['hyper-tps', 'my-app', 'plain-repo'],
    selfPubkeyHex: self,
    readOverlayJson: async (r) => cfgs[r] // async (git read) in production
  })
  t.is(targets.length, 1, 'one mirror target')
  t.alike(targets[0], { repo: 'hyper-tps', peerServerKey: other }, 'the foreign-published repo')
})

test('runOverlayMirror fetches only missing oids into <spool>/<oid> and summarizes', async (t) => {
  const spool = mkdtempSync(path.join(tmpdir(), 'om-run-'))
  writeFileSync(path.join(spool, OID), 'present') // already mirrored

  const fetched = []
  const summary = await runOverlayMirror({
    targets: [{ repo: 'hyper-tps', peerServerKey: 'e'.repeat(64) }],
    mirrorSpool: spool,
    listPointers: async () => ([
      { path: 'a.png', oid: OID, size: 1 },   // present → not fetched
      { path: 'b.glb', oid: OID2, size: 2 }   // missing → fetched
    ]),
    fetchOid: async (peer, oid, dest) => { fetched.push({ peer, oid, dest }); return true },
    deps
  })

  t.is(fetched.length, 1, 'fetched only the missing oid')
  t.is(fetched[0].oid, OID2, 'the missing oid')
  t.is(fetched[0].dest, path.join(spool, OID2), 'destination is content-addressed <spool>/<oid>')
  t.is(fetched[0].peer, 'e'.repeat(64), 'fetched from the publisher')
  t.alike(summary[0], { repo: 'hyper-tps', fetched: 1, missing: 1, total: 2 }, 'summary')
})