This article was originally published on TestProject.
Selenium WebDriver fits in the same role as RC did, and has incorporated the original 1.x bindings. It refers to both the language bindings and the implementations of the individual browser controlling code. This is commonly referred to as just 'WebDriver' or sometimes as Selenium 2. Selenium 1.0 + WebDriver = Selenium 2.0. Introducing WebDriver¶. The primary new feature in Selenium 2.0 is the integration of the WebDriver API. WebDriver is designed to provide a simpler, more concise programming interface in addition to addressing some limitations in the Selenium-RC API. Generated by dossier. In order to perform JavaScript testing with Selenium WebDriver and Mocha in a simple way, WebDriver facilitates usage with MochaJS by wrapping around MochaJS test functions (before, beforeEach, it.
In case you are looking to write a functional test in JavaScript, the following tutorial provides UI automation engineers with the perfect structural reference material for JavaScript testing with Selenium WebDriver 3, Mocha and NodeJS.
These days, JavaScript is a ubiquitous web language which seems to overcome its ‘notorious’ past and has become a more solid platform not only for client-side, but for server domains too. Mocha.js, or simply Mocha, is a feature-rich JavaScript test framework running on Node.js, which provides the platform and the API for building standalone applications server-side using Google’s V8 JavaScript engine at its base.
*Note: to get started with this JavaScript tutorial, you’ll need to be familiar with the basics of NodeJS and the JavaScript programming language.
Tutorial Overview:
1. Mocha Test Construction
2. Using Javascript Selenium 3 API Integrated with MochaJS
Versions used:
1. Constructing Tests with MochaIntroduction to Mocha
As mentioned, Mocha is a JavaScript test framework that runs tests on Node. Mocha comes in the form of a Node package via npm, allowing you to use any library for assertions as a replacement to Node’s standard ‘assert’ function, such as ChaiJS. In addition, Mocha has several similar components to Jasmine, another popular test automation framework which we’ve mentioned in our research for Front End and Unit Test Automation Trends.
Mocha provides an API, which specifies a way to structure the testing code into test suites and test case modules for execution, and later on to produce a test report. Mocha provides two modes for running: either by command line (CLI) or programmatically (Mocha API).
Install Mocha
If Mocha is to be used in CLI, then it should be installed globally as Node.js. Html website project free download.
Install Chai Assertion Module
The
–save option is used to install the module in the project’s scope and not globally.
Test Suite and Test Case Structure
In Mocha, a test suite is defined by the ‘describe’ keyword which accepts a callback function. A test suite can contain child / inner test suites, which can contain their own child test suites, etc. A test case is denoted by the ‘it’ function, which accepts a callback function and contains the testing code.
Mocha supports test suite setup and test case setup functions. A test suite setup is denoted by
before while a test case setup applies beforeEach . beforeEach is actually a common setup for every case in the suite, and will be executed before each case.
As with the setup, Mocha supports test suite and test case teardown functions. A test suite teardown is denoted by
after , while a test case teardown is implemented with afterEach , functions that are executed after a test suite and after each test case respectively.
Create a file that will ‘host’ the test suite, e.g. test_suite.js, and write the following to it;
Running Mocha Test Suite and Test Cases
Mocha supports execution of tests in three ways: Whole Test Suite file, tests filtered by “grep” patterns and tests grep filtering looking in a directory tree (recursive option)
Run whole Test Suite file:
Run a specific suite or test from a specific suite file.
If a suite is selected then all the child suites and/or tests will be executed.
Run a specific suite or test file by searching recursively in a directory tree.
For extensive CLI options:
Managing Syncing of Async Testing Code
In case async functions are used with Mocha and not handled properly, you may find yourself struggling. If asyncing code (e.g. http requests, files, selenium, etc.) is to be used in a test case, follow these guidelines to overcome unexpected results:
1.
done Function
In your test function (
it ) you need to pass the done function down the callback chain — this ensures it is executed after your last step.
The example below emphasizes the done functionality. In this case three seconds of timeout will occur at the end of the test function.
2. Return Promise
Returning a promise is another way to ensure Mocha has executed all code lines when async functions are used (‘done’ function is not needed in this case.)
2. Javascript Selenium 3 Integration with MochaJSSelenium Introduction
Selenium is a library that controls a web browser and emulates the user’s behavior. More specifically, Selenium offers specific language library APIs called ‘bindings’ for the user. These ‘bindings’ act as a client in order to perform requests to intermediate components and acting as servers in order to finally control a Browser.
Selenium APIs, or bindings, now exist in all popular developing languages. All language implementations have now agreed to keep a consistency with the API functions’ naming conventions.
The intermediate components could be the actual webdriver, found natively in each Selenium package, the selenium-standalone-server, as well as vendor native browser controlling drivers — such as Geckodriver for Mozilla, chromedriver for Chrome, etc. Moreover, Selenium webdriver communicates with browser drivers via ‘JsonWired Protocol’ and becomes a W3C Web Standard.
Selenium Installation
Before diving any deeper into Selenium integration with MochaJS, we will take a quick look into Selenium implementation with NodeJS.
In order to use the Selenium API for JavaScript (or Selenium JavaScript bindings), we should install the appropriate module:
At this point, it should be clarified that Javascript Selenium WebDriver can also be referred to as Webdriverjs (although not in npm). Webdrivejs is different than other libs/modules, such as WebdriverIO, Protractor, etc. selenium-webdriver is the official open-source base JavaScript Selenium library while the others are wrapper libraries/frameworks that are built on top of webdriverjs API, claiming to enhance usability and maintenance.
In NodeJS code, the module is used by:
WebDriver Construction
In order to be able to use Selenium, we should build the appropriate ‘webdriver’ object which will then control our browser. Gta 4 full game free. Below, we can see how we use the “Builder” pattern to construct a webdriver object by chaining several functions.
Builder with Options
In the code above, we have managed to build a WebDriver object which aggregates configuration for more than one browser (notice the ‘options’ methods), despite the fact that the
forBrowser() method explicitly sets firefox .
The user can set the
SELENIUM_BROWSER environmental variable on runtime to set the desired browser. It will override any option set by forBrowser , since we have already configured multiple browser capabilities by set<browser_name>Options .
The browser properties can have several types of information depending on the browser under test. For example, in Mozilla’s properties we can set the desired ‘profile’ configuration as follows:
Then, in the above Builder snippet we can add:
Builder with Capabilities
Selenium WebDriver JavaScript API documents several ways that a webdriver could be built. One more possible way is by setting all the required driver configurations in capabilities:
Note that if setOptions are set after
withCapabilities , the configurations will be overridden (e.g. proxy configurations).
Selenium WebDriver Control Flow and Promise Management
Since JavaScript and NodeJS are based on asynchronous principles, Selenium WebDriver behaves in a similar way. In order to avoid callback pyramids and to assist a test engineer with the scripting experience as well as code readability and maintainability, Selenium WebDriver objects incorporate a promise manager that uses a ‘ControlFlow’. ‘ControlFlow’ is a class responsible for the sequential execution of the asynchronous webdriver commands.
Javascript Selenium Webdriver Tutorial
Practically, each command is executed on the
driver object and a promise is returned. The next commands do not need to be nested in ‘thens’, unless there is a need to handle a promise resolved value as follows:
Pointers for JavaScript Testing with Selenium WebDriver and Mocha
This means that we can perform the following:
Note:
title is a promise object and not an actual resolved value.
MochaJS + Selenium WebDriver
Generally speaking, Selenium WebDriver can be integrated with MochaJS since it is used in any plain NodeJS script. However, since Mocha doesn’t know when an asynchronous function has finished before a
done() is called or a promise is returned, we have to be very careful with handling.
Promise Based
Selenium commands are registered automatically, to assure webdriver commands are executed in the correct sequential order a promise should be returned.
The code below shows Mocha’s (before, beforeEach, after, afterEach) or test case body it hooks.
The following actions will be executed:
Selenium Webdriver Support for MochaJS
In order to perform JavaScript testing with Selenium WebDriver and Mocha in a simple way, WebDriver facilitates usage with MochaJS by wrapping around MochaJS test functions (before, beforeEach, it, etc.) with a
test object. This creates a scope that provides awareness that WebDriver is being used. Therefore, there is no need for promise returns.
First, the corresponding module should be loaded:
All the function of Mocha are preceded by ‘test.’ as follows:
And so on. Then, the above code is fully re-written as:
Conclusion
In this tutorial we got a chance to experience JavaScript testing with Selenium WebDriver and MochaJS. We should keep in mind the main difference when comparing to other programming language bindings, due to the asynchronous nature of NodeJS, MochaJS and Selenium WebDriver.
As long as we keep returning promises in any function which creates a promise (either a custom test lib function or a MochaJS hook/testcase), Mocha will execute them in the correct order.
Other frameworks such as WebdriverIO, Protractor and CodeseptJS provide wrapper solutions that hide some configurations from the user, and provide some promise-enhanced handling for a better scripting experience that many test automation experts might find helpful.
Selenium is a browser automation library. Most often used for testingweb-applications, Selenium may be used for any task that requires automatinginteraction with the browser.
Installation
Selenium may be installed via npm with
You will need to download additional components to work with each of the majorbrowsers. The drivers for Chrome, Firefox, and Microsoft's IE and Edge webbrowsers are all standalone executables that should be placed on your systemPATH. Apple's safaridriver is shipped with Safari 10 for OS X El Capitan andmacOS Sierra. You will need to enable Remote Automation in the Develop menu ofSafari 10 before testing.
Usage
The sample below and others are included in the
example directory. You mayalso find the tests for selenium-webdriver informative.
Using the Builder API
The
Builder class is your one-stop shop for configuring new WebDriverinstances. Rather than clutter your code with branches for the various browsers,the builder lets you set all options in one flow. When you callBuilder#build() , all options irrelevant to the selected browser are dropped:
Why would you want to configure options irrelevant to the target browser? The
Builder 's API defines your default configuration. You can change the targetbrowser at runtime through the SELENIUM_BROWSER environment variable. Forexample, the example/google_search.js script is configured to run againstFirefox. You can run the example against other browsers just by changing theruntime environment
The Standalone Selenium Server
The standalone Selenium Server acts as a proxy between your script and thebrowser-specific drivers. The server may be used when running locally, but it'snot recommend as it introduces an extra hop for each request and will slowthings down. The server is required, however, to use a browser on a remote host(most browser drivers, like the IEDriverServer, do not accept remoteconnections).
To use the Selenium Server, you will need to install theJDK anddownload the latest server from Selenium. Once downloaded, run theserver with
You may configure your tests to run against a remote server through the BuilderAPI:
Or change the Builder's configuration at runtime with the
SELENIUM_REMOTE_URL environment variable:
You can experiment with these options using the
example/google_search.js script provided with selenium-webdriver .
Documentation
API documentation is available online from the Selenium project.Additional resources include
Contributing
Contributions are accepted either through GitHub pull requests or patchesvia the Selenium issue tracker. You must sign ourContributor License Agreement before your changes will be accepted.
Node Support Policy![]()
Each version of selenium-webdriver will support the latest semver-minorversion of the LTS and stable Node releases. All semver-major &semver-minor versions between the LTS and stable release will have 'besteffort' support. Following a Selenium release, any semver-minor Node releaseswill also have 'best effort' support. Releases older than the latest LTS,semver-major releases, and all unstable release branches (e.g. 'v.Next')are considered strictly unsupported.
Selenium Webdriver Tutorial Java
For example, suppose the current LTS and stable releases are v6.9.5 and v7.5.0,respectively. Then a Selenium release would have the following support levels:
JmeterSupport Level Definitions
Javascript Selenium Webdriver Wait For ElementProjected Support Schedule
If Node releases a new LTS each October and a new major version every 6months, the support window for selenium-webdriver will be roughly:
Javascript Methods In Selenium Webdriver
IssuesJavascriptexecutor In Selenium Webdriver
Please report any issues using the Selenium issue tracker. When usingthe issue tracker
Js In Selenium Webdriver
License
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