Refactor webdriver setup (#7690)

The setup for each browser web driver instance has been extracted from
`helpers.js` and moved to the `webdriver` directory.

test/e2e/helpers.js

@@ -1,12 +1,10 @@
 const fs = require('fs')
-const path = require('path')
 const mkdirp = require('mkdirp')
 const pify = require('pify')
 const assert = require('assert')
-const os = require('os')
-const { By, Builder, until } = require('selenium-webdriver')
-const { Command } = require('selenium-webdriver/lib/command')
+const { until } = require('selenium-webdriver')
 
+const { buildWebDriver } = require('./webdriver')
 const fetchMockResponses = require('./fetch-mocks.json')
 
 const tinyDelayMs = 200
@@ -33,30 +31,10 @@ module.exports = {
 
 
 async function prepareExtensionForTesting ({ responsive } = {}) {
-  let driver, extensionId, extensionUrl
-  const targetBrowser = process.env.SELENIUM_BROWSER
-  switch (targetBrowser) {
-    case 'chrome': {
-      const extPath = path.resolve('dist/chrome')
-      driver = buildChromeWebDriver(extPath, { responsive })
-      await delay(largeDelayMs)
-      extensionId = await getExtensionIdChrome(driver)
-      extensionUrl = `chrome-extension://${extensionId}/home.html`
-      break
-    }
-    case 'firefox': {
-      const extPath = path.resolve('dist/firefox')
-      driver = buildFirefoxWebdriver({ responsive })
-      await installWebExt(driver, extPath)
-      await delay(largeDelayMs)
-      extensionId = await getExtensionIdFirefox(driver)
-      extensionUrl = `moz-extension://${extensionId}/home.html`
-      break
-    }
-    default: {
-      throw new Error(`prepareExtensionForTesting - unable to prepare extension for unknown browser "${targetBrowser}"`)
-    }
-  }
+  const browser = process.env.SELENIUM_BROWSER
+  const extensionPath = `dist/${browser}`
+  const { driver, extensionId, extensionUrl } = await buildWebDriver({ browser, extensionPath, responsive })
+
   // Depending on the state of the application built into the above directory (extPath) and the value of
   // METAMASK_DEBUG we will see different post-install behaviour and possibly some extra windows. Here we
   // are closing any extraneous windows to reset us to a single window before continuing.
@@ -104,56 +82,6 @@ async function setupFetchMocking (driver) {
   await driver.executeScript(`(${fetchMocking})(${fetchMockResponsesJson})`)
 }
 
-function buildChromeWebDriver (extPath, opts = {}) {
-  const tmpProfile = fs.mkdtempSync(path.join(os.tmpdir(), 'mm-chrome-profile'))
-  const args = [
-    `load-extension=${extPath}`,
-    `user-data-dir=${tmpProfile}`,
-  ]
-  if (opts.responsive) {
-    args.push('--auto-open-devtools-for-tabs')
-  }
-  return new Builder()
-    .withCapabilities({
-      chromeOptions: {
-        args,
-        binary: process.env.SELENIUM_CHROME_BINARY,
-      },
-    })
-    .build()
-}
-
-function buildFirefoxWebdriver (opts = {}) {
-  const driver = new Builder().build()
-  if (opts.responsive) {
-    driver.manage().window().setSize(320, 600)
-  }
-  return driver
-}
-
-async function getExtensionIdChrome (driver) {
-  await driver.get('chrome://extensions')
-  const extensionId = await driver.executeScript('return document.querySelector("extensions-manager").shadowRoot.querySelector("extensions-item-list").shadowRoot.querySelector("extensions-item:nth-child(2)").getAttribute("id")')
-  return extensionId
-}
-
-async function getExtensionIdFirefox (driver) {
-  await driver.get('about:debugging#addons')
-  const extensionId = await driver.wait(until.elementLocated(By.xpath('//dl/div[contains(., \'Internal UUID\')]/dd')), 1000).getText()
-  return extensionId
-}
-
-async function installWebExt (driver, extension) {
-  const cmd = await new Command('moz-install-web-ext')
-    .setParameter('path', path.resolve(extension))
-    .setParameter('temporary', true)
-
-  await driver.getExecutor()
-    .defineCommand(cmd.getName(), 'POST', '/session/:sessionId/moz/addon/install')
-
-  return await driver.schedule(cmd, 'installWebExt(' + extension + ')')
-}
-
 async function checkBrowserForConsoleErrors (driver) {
   const ignoredLogTypes = ['WARNING']
   const ignoredErrorMessages = [

test/e2e/webdriver/chrome.js

@@ -0,0 +1,63 @@
+const { Builder } = require('selenium-webdriver')
+const chrome = require('selenium-webdriver/chrome')
+
+/**
+ * A wrapper around a {@code WebDriver} instance exposing Chrome-specific functionality
+ */
+class ChromeDriver {
+  static async build ({ extensionPath, responsive }) {
+    const args = [
+      `load-extension=${extensionPath}`,
+    ]
+    if (responsive) {
+      args.push('--auto-open-devtools-for-tabs')
+    }
+    const options = new chrome.Options()
+      .addArguments(args)
+    const driver = new Builder()
+      .forBrowser('chrome')
+      .setChromeOptions(options)
+      .build()
+    const chromeDriver = new ChromeDriver(driver)
+    const extensionId = await chromeDriver.getExtensionIdByName('MetaMask')
+
+    return {
+      driver,
+      extensionUrl: `chrome-extension://${extensionId}/home.html`,
+    }
+  }
+
+  /**
+   * @constructor
+   * @param {!ThenableWebDriver} driver a {@code WebDriver} instance
+   */
+  constructor (driver) {
+    this._driver = driver
+  }
+
+  /**
+   * Returns the extension ID for the given extension name
+   * @param {string} extensionName the extension name
+   * @return {Promise<string|undefined>} the extension ID
+   */
+  async getExtensionIdByName (extensionName) {
+    await this._driver.get('chrome://extensions')
+    return await this._driver.executeScript(`
+      const extensions = document.querySelector("extensions-manager").shadowRoot
+        .querySelector("extensions-item-list").shadowRoot
+        .querySelectorAll("extensions-item")
+
+      for (let i = 0; i < extensions.length; i++) {
+        const extension = extensions[i].shadowRoot
+        const name = extension.querySelector('#name').textContent
+        if (name === "${extensionName}") {
+          return extensions[i].getAttribute("id")
+        }
+      }
+
+      return undefined
+    `)
+  }
+}
+
+module.exports = ChromeDriver

test/e2e/webdriver/firefox.js

@@ -0,0 +1,99 @@
+const fs = require('fs')
+const os = require('os')
+const path = require('path')
+const { Builder, By, until } = require('selenium-webdriver')
+const firefox = require('selenium-webdriver/firefox')
+const { Command } = require('selenium-webdriver/lib/command')
+
+/**
+ * The prefix for temporary Firefox profiles. All Firefox profiles used for e2e tests
+ * will be created as random directories inside this.
+ * @type {string}
+ */
+const TEMP_PROFILE_PATH_PREFIX = path.join(os.tmpdir(), 'MetaMask-Fx-Profile')
+
+const GeckoDriverCommand = {
+  INSTALL_ADDON: 'install addon',
+}
+
+/**
+ * A wrapper around a {@code WebDriver} instance exposing Firefox-specific functionality
+ */
+class FirefoxDriver {
+  /**
+   * Builds a {@link FirefoxDriver} instance
+   * @param {{extensionPath: string}} options the options for the build
+   * @return {Promise<{driver: !ThenableWebDriver, extensionUrl: string, extensionId: string}>}
+   */
+  static async build ({ extensionPath, responsive }) {
+    const templateProfile = fs.mkdtempSync(TEMP_PROFILE_PATH_PREFIX)
+    const profile = new firefox.Profile(templateProfile)
+    const options = new firefox.Options()
+      .setProfile(profile)
+    const driver = new Builder()
+      .forBrowser('firefox')
+      .setFirefoxOptions(options)
+      .build()
+    const fxDriver = new FirefoxDriver(driver)
+
+    await fxDriver.init()
+
+    const extensionId = await fxDriver.installExtension(extensionPath)
+    const internalExtensionId = await fxDriver.getInternalId()
+
+    if (responsive) {
+      driver.manage().window().setSize(320, 600)
+    }
+
+    return {
+      driver,
+      extensionId,
+      extensionUrl: `moz-extension://${internalExtensionId}/home.html`,
+    }
+  }
+
+  /**
+   * @constructor
+   * @param {!ThenableWebDriver} driver a {@code WebDriver} instance
+   */
+  constructor (driver) {
+    this._driver = driver
+  }
+
+  /**
+   * Initializes the driver
+   * @return {Promise<void>}
+   */
+  async init () {
+    await this._driver.getExecutor()
+      .defineCommand(
+        GeckoDriverCommand.INSTALL_ADDON,
+        'POST',
+        '/session/:sessionId/moz/addon/install',
+      )
+  }
+
+  /**
+   * Installs the extension at the given path
+   * @param {string} addonPath the path to the unpacked extension or XPI
+   * @return {Promise<string>} the extension ID
+   */
+  async installExtension (addonPath) {
+    const cmd = new Command(GeckoDriverCommand.INSTALL_ADDON)
+      .setParameter('path', path.resolve(addonPath))
+      .setParameter('temporary', true)
+
+    return await this._driver.schedule(cmd)
+  }
+
+  /**
+   * Returns the Internal UUID for the given extension
+   * @return {Promise<string>} the Internal UUID for the given extension
+   */
+  async getInternalId () {
+    await this._driver.get('about:debugging#addons')
+    return await this._driver.wait(until.elementLocated(By.xpath('//dl/div[contains(., \'Internal UUID\')]/dd')), 1000).getText()
+  }
+}
+
+module.exports = FirefoxDriver

test/e2e/webdriver/index.js

@@ -0,0 +1,33 @@
+const { Browser } = require('selenium-webdriver')
+const ChromeDriver = require('./chrome')
+const FirefoxDriver = require('./firefox')
+
+const buildWebDriver = async function buildWebDriver ({ browser, extensionPath, responsive }) {
+  switch (browser) {
+    case Browser.CHROME: {
+      const { driver, extensionId, extensionUrl } = await ChromeDriver.build({ extensionPath, responsive })
+
+      return {
+        driver,
+        extensionId,
+        extensionUrl,
+      }
+    }
+    case Browser.FIREFOX: {
+      const { driver, extensionId, extensionUrl } = await FirefoxDriver.build({ extensionPath, responsive })
+
+      return {
+        driver,
+        extensionId,
+        extensionUrl,
+      }
+    }
+    default: {
+      throw new Error(`Unrecognized browser: ${browser}`)
+    }
+  }
+}
+
+module.exports = {
+  buildWebDriver,
+}