CODEWITHSUNDEEP
javascriptseleniumwebdrivertypeerror
Mr3m4r3
Mr3m4r3

Reputation: 75

Javascript Selenium Webdriver with Edge TypeError: Cannot read property 'start' of null

I'm trying to set up selenium-webdriver example using Javascript and Microsoft Edge. In any other browser this code below works. But Edge won't start. I tried to find a solution, but couldnt find anything that helped me... Maybe you can help.

const {Builder, By, Key, until} = require('selenium-webdriver');

(async function example() {
  let driver = await new Builder().forBrowser('MicrosoftEdge').build();
  try {
    await driver.get('http://www.google.com/ncr');
    await driver.findElement(By.name('q')).sendKeys('webdriver', Key.RETURN);
    await driver.wait(until.titleIs('webdriver - Google Search'), 1000);
  } finally {
    await driver.quit();
  }
})();

Its to easiest example from the webdriver's npm-page. https://www.npmjs.com/package/selenium-webdriver

I'm getting following error:

[Running] node "c:\Users\mr\Desktop\Selenium\SeleniumToJS\test.js"
(node:3700) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): TypeError: Cannot read property 'start' of null
(node:3700) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

[Done] exited with code=0 in 0.512 seconds

If I insert 'edge' instead of 'MicrosoftEdge' follwing returns:

[Running] node "c:\Users\mreinwald\Desktop\Selenium\SeleniumToJS\loginLogout.js"
(node:18112) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): Error: Do not know how to build driver: edge; did you forget to call usingServer(url)?
(node:18112) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

[Done] exited with code=0 in 0.499 seconds

Upvotes: 5

Views: 8708

Answers (3)

Digglit
Digglit

Reputation: 686

I was able to resolve this by importing "Browser" from selenium-webdriver:

const { Browser } = require("selenium-webdriver");

And then creating the edge driver with:

let driver = await new Builder().forBrowser(Browser.EDGE).build();

Upvotes: 1

Qamer Sayeed
Qamer Sayeed

Reputation: 111

The reason for the error is: webdriver is looking for Edge Service to start while creating edge session and it find it to null(as its not set).

The simple solution is create Edge service using Edge drive path.

    const {Builder, By, Key, until} = require('selenium-webdriver');
    const edge = require('selenium-webdriver/edge');
    const edgedriver = require('edgedriver');   //If this driver is already on your system, then no need to install using npm.

    (async function example() {
        let service = await new edge.ServiceBuilder(edgedriver.path);
        let driver = await new Builder.forBrowser('MicrosoftEdge').setEdgeService(service).build();

        try {
            await driver.get('http://www.google.com/ncr');
            //...............
            //...............
        } finally {
            await driver.quit();
        }
    })();

Upvotes: 1

Adelin
Adelin

Reputation: 8219

This line triggers the error:

new Builder().forBrowser('MicrosoftEdge').build();

Cannot read property 'start' of null actually says: "I don't know what MicrosoftEdge is". Basically, in some instances, selenium expects one of: "firefox", "edge" (instead of "MicrosoftEdge"), "chrome", etc

Now

The main topic:

Do not know how to build driver: edge; did you forget to call usingServer(url)?

This can happen due to many reasons:

  1. Is edge installed?
  2. Do you have the latest MicrosoftEdgeDriver server.?
  3. Is MicrosoftEdgeDriver is on your PATH?

If you answer yes to all of the above, then behind the scenes, while building, selenium didn't get the expected capabilities, and, for a last attempt, tries to connect to a remote webDriver (that's why it says usingServer)

As such, to solve this, you can try building the driver yourself, like this:

var edge = require('selenium-webdriver/edge');

var service = new edge.ServiceBuilder()
    .setPort(55555)
    .build();

var options = new edge.Options();
// configure browser options ...

var driver = edge.Driver.createSession(options, service);

And then you can continue with driver.get('http://www.google.com/ncr'); etc.

Upvotes: 6

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