Selenium Concepts

Internal

• Selenium

Overview

Selenium is a set of tools and libraries that can be used to automate testing of UI web applications running in browsers. Modern web browsers expose browser automation APIs that can be used to control the browser and run tests. Selenium operates on those APIs via its WebDriver component and it essentially remotely controls the browser, emulating a user's interaction with the browser: mouse movement, entering text into fields, selecting drop-down values, checking boxes and following links.

Web Browser

Browser Automation APIs

Modern browsers expose browser automation APIs that allow programmatically operating the browser as if a real user would do it. The availability of such API facilitate writing automated tests that simulate very closely a user interaction with the browser and with the application rendered by the browser. The Selenium component that interacts with the browser's automation API is WebDriver.

WebDriver

WebDriver APIs

WebDriver does not require its API to be compiled with the web application code, so it is not intrusive and allows testing the same application that is available in production.

Selenium IDE

https://www.selenium.dev/selenium-ide/

The Selenium IDE is a tool that can be used to develop Selenium test cases. It is offered as Chrome and Firefox extensions. It records the user's actions in the browser and translates them into Selenium commands, producing Selenium scripts. The Selenium IDE can be extended through the use of plugins, which can introduce new commands to the IDE, or integrate with a third-party service.

IDE Plugins

https://www.selenium.dev/selenium-ide/docs/en/plugins/plugins-getting-started

Selenium Scripting

Selenium scripts can be produced by recording the user's actions in a browser via the Selenium IDE. During such a recording session, the IDE generates the appropriate Selenium commands with parameters defined by the context of the element being accessed.

Selenium Grid

https://www.selenium.dev/documentation/en/grid/

Selenium Grid is a tool allowing to run tests cases in different machines across different platforms. The Grid facilitates running the same WebDriver test on multiple browser and operating system combinations.

TO REFACTOR

Selenium Architecture

Selenium has a client-server architecture, and includes both client and server components.

Client

The Selenium client exposes the WebDriver API, which can be used to interact with the page. The client extends RemoteWebDriver, which communicates with the remote Selenium server. There are browser-specific constructors for the WebDriver (ChromeDriver, FirefoxDriver). There is still confusion on whether the client loads and uses a local driver or connects remotely to a server.

Server

The Selenium server receives request from the Selenium client's RemoteWebDriver. It also includes WebDriver API to run tests against web browsers on the server machine.

Navigation to a Web Page

WebDriver driver = new ChromeDriver();
driver.get("http://example.com");