Module-uo/server/test/atlasSourceSelection.test.js

// Which atlas source runs, and what boot does with the answer
// (docs/link/v8.md §10, §17.7; docs/website/SPAWN_ATLAS.md).
//
// The model is the only place that decides between a local ServUO tree and the
// shard bridge, so these drive it with the shard, the database and the
// filesystem all stubbed. Nothing here reaches a real sidecar or a real tree.
//
// The rule under test is the one the cliloc pipeline settled first and this
// inherits: the bridge wins whenever uo-link is configured and enabled, a local
// path is what a site with no shard link uses, and an explicit path is an
// instruction that overrules both.

const { test } = require('node:test')
const assert = require('node:assert/strict')

const atlas = require('../model/shardAtlas/shardAtlas.model')
const db = require('../model/shardAtlas/shardAtlas.db')
const source = require('../utils/spawnAtlasSource')
const uoLinkConfig = require('../model/uoLinkConfig/uoLinkConfig.model')
const { ctx } = require('./_setup')

const saved = {
  getMeta: db.getMeta,
  getPending: db.getPending,
  getFacets: db.getFacets,
  hashFrom: source.hashFrom,
  buildFrom: source.buildFrom,
  getSafe: uoLinkConfig.getSafe,
  settingsGet: ctx.settings.get,
}

function restore() {
  db.getMeta = saved.getMeta
  db.getPending = saved.getPending
  db.getFacets = saved.getFacets
  source.hashFrom = saved.hashFrom
  source.buildFrom = saved.buildFrom
  uoLinkConfig.getSafe = saved.getSafe
  ctx.settings.get = saved.settingsGet
}

/** Whatever source the model chose, captured rather than read. */
function rig({ linked = true, treePath = '', meta = null } = {}) {
  const asked = { hash: [], build: [] }

  uoLinkConfig.getSafe = async () => ({
    enabled: linked,
    baseUrl: linked ? 'http://127.0.0.1:8099' : null,
  })
  ctx.settings.get = async () => treePath

  db.getMeta = async () => meta
  db.getPending = async () => null
  db.getFacets = async () => []

  source.hashFrom = async (descriptor) => {
    asked.hash.push(descriptor)
    return { 'Data/Regions.xml': 'aa' }
  }
  source.buildFrom = async (descriptor) => {
    asked.build.push(descriptor)
    throw new Error('the test stops before a build')
  }

  return asked
}

test('a linked shard is the atlas source, and the configured path is not consulted', async () => {
  const asked = rig({ linked: true, treePath: '/srv/servuo' })

  const status = await atlas.status()

  assert.equal(status.source, 'bridge')
  assert.equal(status.path, 'the shard bridge')
  assert.equal(status.configured, true)
  assert.deepEqual(asked.hash[0], { kind: 'bridge', root: '' })

  restore()
})

test('with no shard linked the configured tree is the source', async () => {
  const asked = rig({ linked: false, treePath: '/srv/servuo' })

  const status = await atlas.status()

  assert.equal(status.source, 'fs')
  assert.equal(status.path, '/srv/servuo')
  assert.deepEqual(asked.hash[0], { kind: 'fs', root: '/srv/servuo' })

  restore()
})

test('an explicit path overrules the bridge — it is an instruction, not a default', async () => {
  const asked = rig({ linked: true, treePath: '/srv/servuo' })

  await atlas.status({ path: '/tmp/other-tree' })

  assert.deepEqual(asked.hash[0], { kind: 'fs', root: '/tmp/other-tree' })

  restore()
})

test('no shard and no path is "nothing configured", not an error', async () => {
  rig({ linked: false, treePath: '' })

  const status = await atlas.status()
  assert.equal(status.configured, false)

  const result = await atlas.refresh()
  assert.equal(result.status, 'skipped')

  restore()
})

test('boot does not call the shard; it says where the import lives instead', async () => {
  // §17.7's rule, and the reason it is not free: an install whose atlas comes
  // over the bridge has NO automatic refresh at all, so the skip has to be
  // deliberate and visible rather than a path that quietly does nothing.
  const asked = rig({ linked: true, treePath: '/srv/servuo' })

  const result = await atlas.refreshOnBoot()

  assert.equal(result.status, 'skipped')
  assert.equal(result.source, 'bridge')
  assert.equal(asked.hash.length, 0, 'boot made no shard call at all')
  assert.equal(asked.build.length, 0)

  restore()
})

test('boot still refreshes by itself from a local tree', async () => {
  const asked = rig({ linked: false, treePath: '/srv/servuo' })

  await atlas.refreshOnBoot()

  assert.deepEqual(asked.hash[0], { kind: 'fs', root: '/srv/servuo' })

  restore()
})

test('a source that cannot be read is reported, with which end could not read it', async () => {
  rig({ linked: true, treePath: '' })

  source.hashFrom = async () => {
    const { TreeBridgeError } = require('../utils/treeBridge')
    throw new TreeBridgeError('the shard is not serving its tree', 'DISABLED')
  }

  const result = await atlas.refresh()

  assert.equal(result.status, 'unavailable')
  assert.equal(result.source, 'bridge')
  assert.equal(result.code, 'DISABLED')

  restore()
})