[javascript] Adding browsers when they are present on the host

Fixes #12456

Author: diemol

javascript/node/selenium-webdriver/testing/index.js

@@ -118,19 +118,20 @@ function getAvailableBrowsers() {
   info(`Searching for WebDriver executables installed on the current system...`)
 
   let targets = [
-    [getPath(new chrome.Options()).driverPath, Browser.CHROME],
-    [getPath(new edge.Options()).driverPath, Browser.EDGE],
-    [getPath(new firefox.Options()).driverPath, Browser.FIREFOX],
-    [getPath(new ie.Options()).driverPath, Browser.INTERNET_EXPLORER],
-    [getPath(new safari.Options()).driverPath, Browser.SAFARI],
+    [getPath(new chrome.Options()), Browser.CHROME],
+    [getPath(new edge.Options()), Browser.EDGE],
+    [getPath(new firefox.Options()), Browser.FIREFOX],
+    [getPath(new ie.Options()), Browser.INTERNET_EXPLORER],
+    [getPath(new safari.Options()), Browser.SAFARI],
   ]
 
   let availableBrowsers = []
   for (let pair of targets) {
-    const driverPath = pair[0]
+    const driverPath = pair[0].driverPath
+    const browserPath = pair[0].browserPath
     const name = pair[1]
     const capabilities = pair[2]
-    if (driverPath.length > 0) {
+    if (driverPath.length > 0 && browserPath && browserPath.length > 0) {
       info(`... located ${name}`)
       availableBrowsers.push({ name, capabilities })
     }