Introduction to Automation & Selenium

Selenium Suite Overview (IDE, WebDriver, Grid)

Learning Outcome

Topic Name-Recall(Slide3)

Imagine a tester working on an e-commerce website

Every day the tester must check:

Imagine a tester working on an e-commerce website

After several hours of testing:

Transition from Analogy to Technical Concept(Slide 5)

This is where Selenium is used.

• Repeating the same steps every day → Automation scripts

• Tester getting tired → Automated execution

• Missing bugs due to repetition → Consistent test execution

Testing across multiple browsers → Cross-browser automatio

Selenium is an automation testing tool that helps testers automatically execute test cases on web applications across different browsers and environments.

Why Bugs Escape After Manual Testing

• Testers may become tired after repetitive testing tasks

• Some test scenarios might be missed accidentally

• Testing on multiple browsers takes a lot of time

• Manual testing cannot easily run thousands of test cases quickly

With Selenium automation:

• Tests run faster and consistently

• Thousands of tests can run in minutes

• Testing can be performed across multiple browsers and devices

Types of Selenium

What is Selenium IDE?

• Point-and-click recording of browser interactions

• Export tests to WebDriver code (Java, Python, etc.)

• Control flow commands for conditional testing

• Debug and breakpoint functionality

• Only supports Chrome and Firefox browsers

• Cannot handle complex authentication scenarios

• Limited cross-browser testing capabilities

• Not suitable for large-scale test suites

Key Features

Limitations

What is Selenium RC?

• Selenium RC (Remote Control) was the first tool in the Selenium Suite
• It enabled testers to write automated web application UI tests in any programming language

• ​Selenium Server injected JavaScript into browsers to control them
• Test scripts communicated with the server via HTTP

Definition

Used Client-Server Architecture

What It Is WebDriver

• A robust API that allows direct browser control through language-specific bindings
• The successor to Selenium RC, WebDriver communicates natively with browser internals

Definition

• Cross-browser: Chrome, Firefox, Safari, Edge, IE

• Multi-language: Java, Python, C#, JavaScript, Ruby

• Simulates precise user interactions like clicks, typing, and gestures

• Supports headless execution for CI/CD pipelines

Benefits

Parallel Testing with Selenium Grid

Central Hub:

Routes JSON test commands to appropriate nodes based on browser/OS requirements and manages the test queue for optimal resource allocation

Multiple Nodes:

Execute tests across Chrome, Firefox, Safari, and Edge on Windows, macOS, and Linux environments simultaneously, supporting cross-browser compatibility testing

Time Savings:

Reduce 10-hour sequential test suites to just 12 minutes by running 50 tests in parallel, cutting regression testing time by up to 95%

How Does Selenium Talk to the Browser?

Test Script

Selenium code in Java, Python, C#, or JavaScript sends browser control commands

WebDriver API

Converts language-specific code to JSON wire protocol messages

Protocol

W3C WebDriver protocol transmits HTTP requests with browser instructions

Browser 

Browser driver receives commands and manipulates DOM elements accordingly

Why the Name “Selenium”?

The name “Selenium” was coined humorously as a joke

Fun Fact

The name stuck and became a symbol of open-source alternatives to expensive test automation tools

The Story Behind the Name

At the time, a competing proprietary tool was Mercury QuickTest Professional (QTP).Since selenium is a chemical element known to counteract mercury poisoning, the open-source tool was named Selenium to mock Mercury

Why Selenium Still Rules Automation

IDE:

• A record-and-playback tool that automatically generates code in Java, Python, or C#
• Useful for beginners and quick automation experiments

WebDriver:

• Uses the W3C WebDriver protocol to provide a consistent API for browsers like Chrome, Firefox, Edge, and Safari

Selenium RC:

• The first Selenium tool that automated browsers using a server and JavaScript
• Now deprecated but it laid the foundation for WebDriver

Grid:

• Runs tests on multiple machines and browsers at the same time, reducing test execution time

CI/CD:

• Integration Integrates with tools like Jenkins and GitHub Actions to run automated tests after each code commit, helping detect UI bugs early

Summary

What architecture did Selenium RC use?

What architecture did Selenium RC use?