[Part 5]Functions and Modules – Writing Reusable and Modular JavaScript QA Code

Introduction

Functions and modules help create reusable and maintainable test automation scripts. This module covers function declarations, parameterization, modularization, and working with external libraries to enhance test automation workflows.

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Lesson 1: Defining and Calling Functions in JavaScript – Code Reusability in Action

Concept:
Functions allow reusing logic across multiple test cases, improving efficiency and reducing redundancy.

Key Topics:

• Function Declaration: Creating named functions.
• Function Expression: Assigning functions to variables.
• Arrow Functions: Writing concise modern JavaScript functions.
• Calling Functions: Executing functions within test cases.

Example:

function validateTestResult(actual, expected) {
    return actual === expected ? "Test Passed" : "Test Failed";
}

console.log(validateTestResult("Success", "Success"));

Pro Tip: Use descriptive function names to enhance code readability and maintainability.

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Lesson 2: Function Parameters and Return Values – Designing Flexible Functions

Concept:
Functions can accept parameters and return values, making them versatile for various test scenarios.

Key Topics:

• Parameters: Passing values into functions.
• Default Parameters: Assigning default values to function parameters.
• Rest Parameters: Handling dynamic arguments using ...args.
• Return Values: Returning outputs from functions.

Example:

function generateTestReport(testName = "Unknown", status = "Pending") {
    return `Test: ${testName}, Status: ${status}`;
}

console.log(generateTestReport("Login", "Passed"));

Pro Tip: Use default parameters to prevent errors when arguments are missing.

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Lesson 3: Working with JavaScript Modules and npm – Expanding Script Capabilities

Concept:
JavaScript modules allow organizing test scripts into separate files, improving maintainability and reusability.

Key Topics:

• Module Basics: Understanding the concept of modular JavaScript.
• Exporting and Importing: Sharing functions across files.
• Using npm Packages: Managing external libraries for automation.
• Installing Packages: Adding third-party libraries using npm.

Example:
Creating a module (testUtils.js):

export function isEqual(a, b) {
    return a === b;
}

Importing the module (main.js):

import { isEqual } from "./testUtils.js";
console.log(isEqual(10, 10));

Pro Tip: Organize helper functions in separate modules to keep test scripts clean and maintainable.

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Lesson 4: Creating and Organizing Your Own JavaScript Modules for QA Projects

Concept:
Custom JavaScript modules enable scalable and maintainable test automation projects.

Key Topics:

• Module Planning: Structuring reusable components.
• Creating Modules: Writing modular functions for test cases.
• Exporting and Importing: Managing dependencies within a project.
• Organizing a QA Project: Structuring test automation repositories.

Example:

// testFunctions.js
export function checkStatus(status) {
    return status === "Passed" ? "✅" : "❌";
}

Importing the module:

import { checkStatus } from "./testFunctions.js";
console.log(checkStatus("Passed"));

Pro Tip: Use an organized folder structure (/utils, /tests, /config) to manage test scripts efficiently.

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Conclusion

This module covered the importance of functions and modules in JavaScript test automation, enabling the creation of reusable, modular, and scalable test scripts.

Key Takeaways:

• Functions make test scripts reusable and maintainable.
• Parameterized functions enhance flexibility in automation.
• JavaScript modules organize test logic into manageable components.
• npm packages extend automation capabilities with external tools.

What’s Next?
In the next module, we will dive into Error Handling and Exception Handling in JavaScript for Robustness, where we will explore techniques to catch, log, and handle errors in test automation scripts.

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