What is webdriverIO?

WebdriverIO Test Runner

This is the most popular way of using webdriverIO.

The test runner is basically a framework that makes test automation much easier. For example, here are some of the inherent advantages of using the test runner:

  • Extra hooks: Hooks will allow you the capability to perform actions before and after execution of tests.
  • Default async/await usage: WebDriver commands are asynchhronous by nature. As a result, every command will require an await before it. Which can be a little repetitive and annoying. The test runner handles this for you so that you don’t need to worry about it.
  • Suites: Suites allow you to separate different sections of your test suite so that you can run them individually.
  • Parallel test runs: Parallelization is the most powerful way to speed up your suite execution. Besides that, parallelization is mandatory to any test automation program.
  • Automatic session deletion: Normally you have to do something like this in your tests await browser.deleteSession(); But, the test runner takes care of that part for us.

Tips + Tricks

  • If you are constantly having permission issues installing stuff, run npm config set unsafe-perm true that will put you into an administrator shell through which you can run all of your installation commands.

WebdriverIO test runner tutorial

This is the one the version that you want to use. It comes with everything you need out of the box. There’s also webdriverio standalone that you can use but I don’t feel like it has much use.

How to get started

Official docs are here

1.Create a new directory and navigate to that directory

mkdir wdio-testrunner && cd wdio-testrunner

2.Initialize a new NPM project with npm init -y . This will create a package.json file

If you don’t do this, when you go to do npm install no packages will actually be installed.

3. Install the command line interface npm install @wdio/cli. All the official WebdriverIO packages are namespaced under the @wdio scope

If you encounter any permissions errors here, you can try:

sudo npm i --save-dev @wdio/cli --unsafe-perm=true --allow-root

Or just set this globally for npm and it will stop complaining:

npm config set unsafe-perm true

The CLI tool is a wrapper around the main webdriverIO functionality, we will work through the CLI.

Since @wdio/cli is a command-line utility, it’s setup to install to a special .bin folder inside our node_modules directory. This gives us two ways to run the utility:
$ ./node_modules/.bin/wdio
$ npx wdio

4. Let’s configure webdriverIO using npx wdio

Answer the questions

  1. Where should your tests be launched? Enter
  2. Shall I install the runner plugin for you? Y
  3. Where is your automation backend located? For now, our tests will execute on our local machine through our selenium server
  4. Which framework do you want to use? mocha
  5. Shall I install the framework adapter for you? Y . This will install our framework that we would like to use.
  6. Do you want to run WebdriverIO commands synchronous or asynchronous? sync . This will make sure that you don’t have to keep using async with every command
  7. Where are your test specs located? (./test/specs/*/.js)? Enter
  8. Which reporter do you want to use? spec . We will keep things simple for now.
  9. Do you want to add a service to your test setup? selenium-standalone . Make sure that you press the Space key to select one or more options. Press Enter after you are done.
  10. Level of logging verbosity: Info
  11. What is the base url? Enter the base url of your website

I’d like to bring to your attention that the ** and * in the path is called a Glob pattern. That’s a convention used to define where multiple files are at.
The ** section says to look in all the sub-folders for files, if we later organize our tests by feature (say we add a login or checkout folder) WebdriverIO will know to look in those subfolders as well as the main test/specs folder.
The * portion in *.js matches any file that ends with a .js extension. It will match test.js and login.js but not test.txt or just login.

How to run a webdriverIO test

1.Create a new folder for our tests mkdir -p ./test/specs

First, when we setup the webdriverIO test runner, we specified the location of all of tests in the wdio.conf.js. So, any tests that we put inside the spec folder will be executed. This is the configuration in the file.

Now we have the folder for our tests. Let’s actually add a test:

2. Using command line, create a new file touch ./test/specs/example.js

Where all of the test files should live

3. Add this code to the example.js file

4. Run the test using npx wdio or ./node_modules/.bin/wdio

Note: Make sure that you have the appropriate browser installed. In the previous examples, we installed Chrome. Hence, if that’s what you have then set that in the wdio.conf.js because the default is Firefox.

chrome browser cap
Set browser to chrome

WebdriverIO QuickStart

  1. Clone this repo
  2. Install dependencies using npm install
  3. Run tests npx wdio

Cool WebdriverIO features

  • Interactions with elements with only a single command: This means that to click an element, you simple have to use this command browser.click('element locator'). This will also find the element and then click it if it’s found. This is actually two web requests for a single method call.

Command line options

Dynamic URLs

You can dynamically set your application URL through command line.

Execute the tests SERVER=prod ./node_modules/.bin/wdio --logLevel=trace

NPM scripts

NPM scripts documentation

Using these scripts, we can make testing easier.

For example, we can update package.json

To look like this:

And now we can run the tests like this npm test wdio

If you want to add command line parameters to the scripts, you need to prefix them with -- like this npm test -- --logLevel=info

However, if you want to change environment variables, do just like before:

SERVER=prod npm test -- --logLevel=trace

WebdriverIO standalone tutorial

How to install WebdriverIO

  1. Make a directory mkdir wdio-standalone
  2. Navigate to the new directory cd wdio-standalone
  3. Initialize the project as an NPM project withnpm init -y. This will create a package.json file.
  4. Install WebdriverIO with npm install webdriverio . This will install all of the packages that are relevant for WebdriverIO. Note: Installing WebdriverIO via the command line doesn’t give you all of the NPM packages that you need. We do get a Node.js module.
  5. Create a new file with touch test.js
  6. Open the file and let’s add some code to it

Next, we’ll need to install Selenium Server…

How to install selenium-standalone


1. Run command sudo npm i -g selenium-standalone

2. Install the resources from the server sudo selenium-standalone install

3. To start the server, you can run selenium-standalone start. Make sure to do this in a separate Terminal window

You know that you succeeded if you can hit this URL: http://localhost:4444/wd : and see something like this.


How to run webdriverIO test with selenium-standalone?

1. In your terminal with wdio-standalone installed, run node test.js. This will tell Node.js to run the test.js file.

If successful, you will see a chrome browser come up quickly and you will see some commands logged that look like this

webdriverio logs

How to run webdriverIO with chromedriver?

Chromedriver uses port 9515 to listen for commands to come through. That’s a bit different from Selenium server that runs on port 4444.

This is the default configuration that runs on selenium server.

To update it to use chromedriver, change the configuration to this:

Now, you will want to install and run chromedriver below…

How to install and run chromedriver

1.Open terminal and run npm install -g chromedriver

Note: You might run into some errors here like Missing write access or Chromedriver installation failed. Follow those links for solutions.

2. Run chromedriver in a separate terminal window by running chromedriver command. This is what success looks like:

chromedriver success

You can also hit http://localhost:9515/ and make sure that you get back a response. That will tell you if chromedriver is running or not.

How to run a webdriverIO test on chromedriver?

1.Once you have chromedriver running with the chromedriver command

2.Execute node test.js to run your tests on Chrome

Debugging WebdriverIO tests

You can add a browser.debug(); command anywhere in your test code and the execution will stop there.

At some point, the debug point will time out so that our test isn’t hanging for too long. In debugging of course, we want to have this timeout be longer…

We can change that and it’s based on the testing framework that you are using.

Mocha API

Here’s the Mocha API

We can update the timeout either using the mocha.opts file or via command line.

For WebriverIO, the settings are actually in the wdio.conf.js file. So we can just change them there. The timeout setting is in ms.

You can imagine that it’s a bit annoying to keep changing these values. Especially, when you forget to change it back in production, potentially leaving your tests to hang.

There’s documentation on how to do this dynamically from WebdriverIO here.

Here’s an example of how to do this:

Now you can set the timeout using command line and use the longer option DEBUG=true npx wdio

My questions

  • Changing to this import { notStrictEqual } from 'assert'; from this const assert = require('assert'); doesn’t work for some reason when I run npx test.
  • How to download some source code and start working with it.

Learn WebdriverIO Course


  • Install NodeJS

1. Clone this repo

2. Navigate to the directory of the repo cd webdriver-io-course-content

3. Run npm install to download all of the dependencies

4. Run npm start which will start the application on your local environment

5. Go to one of the URLs to see the website running

Common errors

Missing write access to /usr/local/lib/node_modules…

npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules
 npm ERR! path /usr/local/lib/node_modules
 npm ERR! code EACCES
 npm ERR! errno -13
 npm ERR! syscall access
 npm ERR! Error: EACCES: permission denied, access '/usr/local/lib/node_modules'
 npm ERR!  { [Error: EACCES: permission denied, access '/usr/local/lib/node_modules']
 npm ERR!   stack:
 npm ERR!    'Error: EACCES: permission denied, access \'/usr/local/lib/node_modules\'',
 npm ERR!   errno: -13,
 npm ERR!   code: 'EACCES',
 npm ERR!   syscall: 'access',
 npm ERR!   path: '/usr/local/lib/node_modules' }
 npm ERR! 
 npm ERR! The operation was rejected by your operating system.
 npm ERR! It is likely you do not have the permissions to access this file as the current user
 npm ERR! 
 npm ERR! If you believe this might be a permissions issue, please double-check the
 npm ERR! permissions of the file and its containing directories, or try running
 npm ERR! the command again as root/Administrator (though this is not recommended).
 npm ERR! A complete log of this run can be found in:
 npm ERR!     /Users/nikolay/.npm/_logs/2019-04-14T14_28_32_628Z-debug.log

The solution

This is an issue with write permissions to your disk. If you see these kinds of errors, simply run the command with sudo.

sudo npm install -g chromedriver

ChromeDriver installation failed { Error: EACCES: permission denied …

ChromeDriver installation failed { Error: EACCES: permission denied, mkdir '/usr/local/lib/node_modules/chromedriver/lib/chromedriver'
     at Object.mkdirSync (fs.js:753:3)
     at /usr/local/lib/node_modules/chromedriver/install.js:282:10
   errno: -13,
   syscall: 'mkdir',
   code: 'EACCES',
   path: '/usr/local/lib/node_modules/chromedriver/lib/chromedriver' }
 npm ERR! errno 1
 npm ERR! [email protected] install: node install.js
 npm ERR! Exit status 1
 npm ERR! 
 npm ERR! Failed at the [email protected] install script.
 npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
 npm ERR! A complete log of this run can be found in:
 npm ERR!     /Users/nikolay/.npm/_logs/2019-04-14T14_31_21_148Z-debug.log

The solution

Run this command instead that I got from here:

sudo npm i -g chromedriver --unsafe-perm=true --allow-root


  1. Clone this repository that has some sample working tests
  2. You can run tests in Sauce Labs by running this command npm run wdio wdio.sauce.conf.js

The package.json file has this configuration that tells us which commands to execute for which scenario. If we want to run on Sauce Labs, the command we use is the one below:

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