const LocalMessageDuplexStream = require('post-message-stream') const PongStream = require('ping-pong-stream/pong') const PortStream = require('./lib/port-stream.js') const ObjectMultiplex = require('./lib/obj-multiplex') const extension = require('extensionizer') const fs = require('fs') const path = require('path') const inpageText = fs.readFileSync(path.join(__dirname, 'inpage.js')).toString() // Eventually this streaming injection could be replaced with: // https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XPCOM/Language_Bindings/Components.utils.exportFunction // // But for now that is only Firefox // If we create a FireFox-only code path using that API, // MetaMask will be much faster loading and performant on Firefox. if (shouldInjectWeb3()) { setupInjection() setupStreams() } function setupInjection () { try { // inject in-page script var scriptTag = document.createElement('script') scriptTag.src = extension.extension.getURL('scripts/inpage.js') scriptTag.textContent = inpageText scriptTag.onload = function () { this.parentNode.removeChild(this) } var container = document.head || document.documentElement // append as first child container.insertBefore(scriptTag, container.children[0]) } catch (e) { console.error('Metamask injection failed.', e) } } function setupStreams () { // setup communication to page and plugin var pageStream = new LocalMessageDuplexStream({ name: 'contentscript', target: 'inpage', }) pageStream.on('error', console.error) var pluginPort = extension.runtime.connect({name: 'contentscript'}) var pluginStream = new PortStream(pluginPort) pluginStream.on('error', console.error) // forward communication plugin->inpage pageStream.pipe(pluginStream).pipe(pageStream) // setup local multistream channels var mx = ObjectMultiplex() mx.on('error', console.error) mx.pipe(pageStream).pipe(mx) // connect ping stream var pongStream = new PongStream({ objectMode: true }) pongStream.pipe(mx.createStream('pingpong')).pipe(pongStream) // ignore unused channels (handled by background) mx.ignoreStream('provider') mx.ignoreStream('publicConfig') } function shouldInjectWeb3 () { return doctypeCheck() || suffixCheck() } function doctypeCheck () { const doctype = window.document.doctype if (doctype) { return doctype.name === 'html' } else { return false } } function suffixCheck () { var prohibitedTypes = ['xml', 'pdf'] var currentUrl = window.location.href var currentRegex for (let i = 0; i < prohibitedTypes.length; i++) { currentRegex = new RegExp(`\.${prohibitedTypes[i]}$`) if (currentRegex.test(currentUrl)) { return false } } return true }