bare-operating-system/packages/bare-os-coreutils/lib/summon-js.js

/** Run page JS on Bare (ctx.bare.bareVm / bare-realm) or a strict Function sandbox. */

var BARE_SUMMON_JS_MAX_SCRIPTS = 16
var BARE_SUMMON_JS_MAX_SOURCE = 256 * 1024
var BARE_SUMMON_JS_MAX_TIMERS = 32

function bareSummonResolveVm(ctx) {
  if (ctx && typeof ctx.bareOsSummonEval === 'function') {
    return { kind: 'syscall', eval: ctx.bareOsSummonEval }
  }
  var b = ctx && ctx.bare
  var vm = b && (b.bareVm || b.vm)
  if (vm && vm.default) vm = vm.default
  if (
    vm &&
    typeof vm.createContext === 'function' &&
    typeof vm.runInContext === 'function'
  ) {
    return { kind: 'vm', vm: vm }
  }
  return { kind: 'function' }
}

function bareSummonMakeConsole(sink) {
  function push(level, args) {
    var msg = []
    var i
    for (i = 0; i < args.length; i++) {
      try {
        msg.push(typeof args[i] === 'string' ? args[i] : String(args[i]))
      } catch (e) {
        msg.push('[unprintable]')
      }
    }
    sink.push({ level: level, text: msg.join(' ') })
  }
  return {
    log: function () {
      push('log', arguments)
    },
    info: function () {
      push('info', arguments)
    },
    warn: function () {
      push('warn', arguments)
    },
    error: function () {
      push('error', arguments)
    },
    debug: function () {
      push('debug', arguments)
    }
  }
}

function bareSummonMakeLocation(href) {
  var u = bareSummonParseUrl(href) || {
    href: String(href || ''),
    protocol: '',
    host: '',
    hostname: '',
    port: '',
    pathname: '/',
    search: '',
    hash: '',
    origin: ''
  }
  return {
    href: u.href,
    protocol: u.protocol,
    host: u.host,
    hostname: u.hostname,
    port: u.port,
    pathname: u.pathname,
    search: u.search,
    hash: u.hash,
    origin: u.origin,
    toString: function () {
      return this.href
    }
  }
}

function bareSummonEvalSource(engine, source, sandbox) {
  if (engine.kind === 'syscall') {
    return engine.eval(source, sandbox)
  }
  if (engine.kind === 'vm') {
    var box = engine.vm.createContext()
    var k
    for (k in sandbox) {
      if (Object.prototype.hasOwnProperty.call(sandbox, k)) box[k] = sandbox[k]
    }
    return engine.vm.runInContext(
      'var window = this; var self = this; var globalThis = this;\n' + source,
      box
    )
  }
  var fn = new Function(
    'window',
    '"use strict";' +
      'var self = window;' +
      'var document = window.document;' +
      'var console = window.console;' +
      'var location = window.location;' +
      'var navigator = window.navigator;' +
      'var setTimeout = window.setTimeout;' +
      'var clearTimeout = window.clearTimeout;' +
      'var fetch = window.fetch;' +
      source
  )
  return fn(sandbox.window || sandbox)
}

async function bareSummonCollectScriptJobs(session, doc, pageUrl) {
  var jobs = []
  var nodes = (doc && doc.scripts) || []
  var i
  for (
    i = 0;
    i < nodes.length && jobs.length < BARE_SUMMON_JS_MAX_SCRIPTS;
    i++
  ) {
    var n = nodes[i]
    var src = n.attrs && n.attrs.src
    var type = ((n.attrs && n.attrs.type) || 'text/javascript').toLowerCase()
    if (
      type &&
      type !== 'text/javascript' &&
      type !== 'application/javascript' &&
      type !== 'module' &&
      type !== ''
    ) {
      if (type.indexOf('javascript') < 0 && type !== 'module') continue
    }
    if (src) {
      var abs = bareSummonResolveUrl(src, pageUrl)
      if (!abs || !bareSummonIsHttp(abs)) continue
      jobs.push({ node: n, url: abs.href, source: '', external: true })
    } else {
      var body = bareSummonScriptSource(n)
      if (body)
        jobs.push({ node: n, url: pageUrl, source: body, external: false })
    }
  }
  for (i = 0; i < jobs.length; i++) {
    if (!jobs[i].external) continue
    var res = await bareSummonFetch(session.ctx, jobs[i].url, {
      jar: session.jar,
      maxBytes: BARE_SUMMON_JS_MAX_SOURCE
    })
    jobs[i].source = (res && res.body) || ''
    if (jobs[i].source.length > BARE_SUMMON_JS_MAX_SOURCE) {
      jobs[i].source = jobs[i].source.slice(0, BARE_SUMMON_JS_MAX_SOURCE)
    }
  }
  return jobs
}

async function bareSummonRunDocumentJs(session, doc, pageUrl) {
  var logs = []
  var errors = []
  var ran = 0
  var engine = bareSummonResolveVm(session && session.ctx)
  var timers = []
  var tid = 0
  var env = { console: bareSummonMakeConsole(logs) }
  var document = bareSummonCreateDocumentApi(doc, env)
  var location = bareSummonMakeLocation(pageUrl)
  var window = {
    document: document,
    console: env.console,
    location: location,
    navigator: {
      userAgent: 'Summon/0.2 (Bare OS; text; bare-vm)',
      platform: 'bare',
      language: 'en'
    },
    innerWidth: session.cols || 80,
    innerHeight: 24,
    devicePixelRatio: 1,
    setTimeout: function (fn, ms) {
      if (timers.length >= BARE_SUMMON_JS_MAX_TIMERS) return 0
      tid++
      timers.push({ id: tid, fn: fn, ms: ms | 0 })
      return tid
    },
    clearTimeout: function (id) {
      timers = timers.filter(function (t) {
        return t.id !== id
      })
    },
    fetch: function () {
      return Promise.reject(new Error('summon: page fetch is not enabled'))
    }
  }
  window.window = window
  window.self = window
  env.document = document

  var jobs = await bareSummonCollectScriptJobs(session, doc, pageUrl)
  var i
  for (i = 0; i < jobs.length; i++) {
    var src = jobs[i].source
    if (!src || src.length > BARE_SUMMON_JS_MAX_SOURCE) continue
    try {
      bareSummonEvalSource(engine, src, {
        window: window,
        document: document,
        console: env.console,
        location: location,
        navigator: window.navigator
      })
      ran++
    } catch (err) {
      errors.push({
        url: jobs[i].url,
        message: (err && err.message) || String(err)
      })
      env.console.error((err && err.message) || String(err))
    }
  }
  for (i = 0; i < timers.length; i++) {
    if (typeof timers[i].fn === 'function') {
      try {
        timers[i].fn.call(window)
      } catch (e2) {
        errors.push({ url: pageUrl, message: (e2 && e2.message) || String(e2) })
      }
    }
  }
  bareSummonFlushInlineStyle(doc.body)
  bareSummonFlushInlineStyle(doc.head)
  return {
    engine: engine.kind,
    ran: ran,
    blocked: Math.max(0, ((doc.scripts && doc.scripts.length) || 0) - ran),
    logs: logs,
    errors: errors
  }
}