feat: Allow to elevate system privileges in runtime (#191)

lib/installer.js

@@ -5,6 +5,7 @@ import { exec } from 'teen_process';
 import log from './logger';
 import ES6Error from 'es6-error';
 import { queryRegistry } from './registry';
+import { shellExec } from './utils';
 
 // https://github.com/microsoft/WinAppDriver/releases
 const WAD_VER = '1.2.99';
@@ -49,7 +50,7 @@ async function fetchMsiInstallLocation (installerGuid) {
   const scriptPath = path.join(tmpRoot, 'get_wad_inst_location.vbs');
   try {
     await fs.writeFile(scriptPath, INST_LOCATION_SCRIPT_BY_GUID(installerGuid), 'latin1');
-    const {stdout} = await exec('cscript.exe', ['/Nologo', scriptPath]);
+    const {stdout} = await shellExec('cscript.exe', ['/Nologo', scriptPath]);
     return _.trim(stdout);
   } finally {
     await fs.rimraf(tmpRoot);
@@ -125,14 +126,14 @@ async function downloadWAD () {
   return installerPath;
 }
 
-const isAdmin = _.memoize(async function isAdmin () {
+const isAdmin = async function isAdmin () {
   try {
     await exec('fsutil.exe', ['dirty', 'query', process.env.SystemDrive || 'C:']);
     return true;
   } catch (ign) {
     return false;
   }
-});
+};
 
 async function setupWAD () {
   if (!system.isWindows()) {
@@ -148,14 +149,14 @@ async function setupWAD () {
     log.info(`WinAppDriver doesn't exist, setting up`);
   }
 
-  if (!await isAdmin()) {
-    throw new Error(`You are not running as an administrator so WinAppDriver cannot be installed for you; please reinstall as admin`);
-  }
-
   const installerPath = await downloadWAD();
   log.info(`Running WinAppDriver v${WAD_VER} installer`);
   try {
-    await exec(installerPath, ['/install', '/quiet', '/norestart']);
+    await shellExec(installerPath, ['/install', '/quiet', '/norestart']);
+  } catch (e) {
+    /** @type {import('node:child_process').ExecException} */
+    const error = e;
+    throw new Error(`WinAppDriver cannot be installed: ${error.message}. Exit code: ${error.code}`);
   } finally {
     await fs.rimraf(installerPath);
   }

lib/registry.js

@@ -1,5 +1,5 @@
 import _ from 'lodash';
-import { exec } from 'teen_process';
+import { shellExec } from './utils';
 
 const REG = 'reg.exe';
 const ENTRY_PATTERN = /^\s+(\w+)\s+([A-Z_]+)\s*(.*)/;
@@ -62,7 +62,7 @@ function parseRegQueryOutput (output) {
 async function queryRegistry (root) {
   let stdout;
   try {
-    ({stdout} = await exec(REG, ['query', root, '/s']));
+    ({stdout} = await shellExec(REG, ['query', root, '/s']));
   } catch (e) {
     return [];
   }

lib/utils.js

@@ -0,0 +1,26 @@
+import { util} from 'appium/support';
+import { promisify } from 'node:util';
+import { exec } from 'node:child_process';
+import B from 'bluebird';
+
+const execAsync = promisify(exec);
+
+/**
+ * This API triggers UAC when necessary
+ * unlike the 'spawn' call used by teen_process's exec.
+ * See https://github.com/nodejs/node-v0.x-archive/issues/6797
+ *
+ * @param {string} cmd
+ * @param {string[]} args
+ * @param {import('node:child_process').ExecOptions & {timeoutMs?: number}} opts
+ * @returns {Promise<{stdout: string; stderr: string;}>}
+ * @throws {import('node:child_process').ExecException}
+ */
+export async function shellExec(cmd, args = [], opts = {}) {
+  const {
+    timeoutMs = 60 * 1000 * 5
+  } = opts;
+  const fullCmd = util.quote([cmd, ...args]);
+  return await B.resolve(execAsync(fullCmd, opts))
+    .timeout(timeoutMs, `The command '${fullCmd}' timed out after ${timeoutMs}ms`);
+}