[Part 3]Control Flow and Decision Making in JavaScript for QA Scripts

Introduction

Control flow structures are essential for decision-making and executing test cases efficiently. This module covers conditional statements, loops, boolean logic, and their applications in JavaScript-based test automation.

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Lesson 1: Conditional Statements – if, else if, else for Test Logic

Concept:
Conditional statements allow test scripts to make decisions based on logic.

Key Topics:

• if Statement: Execute code if a condition is true.
• else if Statement: Handle multiple conditions.
• else Statement: Define a fallback execution path.
• Nested Conditionals: Implement complex decision trees.

Example:

let testResult = "Passed";
if (testResult === "Passed") {
    console.log("Test successful!");
} else if (testResult === "Failed") {
    console.log("Test failed, needs debugging.");
} else {
    console.log("Test result unknown.");
}

Pro Tip: Use switch statements for handling multiple possible values efficiently.

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Lesson 2: Mastering Loops – for, while, and for...of Loops

Concept:
Loops automate repetitive tasks in test scripts.

Key Topics:

• for Loop: Iterates a set number of times.
• while Loop: Runs while a condition is true.
• for...of Loop: Iterates over iterable objects.

Example:

let testCases = ["Login", "Signup", "Checkout"];
for (let test of testCases) {
    console.log(`Executing ${test} test`);
}

Pro Tip: Avoid infinite loops by ensuring loop conditions are correctly defined.

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Lesson 3: Boolean Logic and Assertions in JavaScript

Concept:
Boolean logic helps in making comparisons and assertions in test scripts.

Key Topics:

• Boolean Values: True and false conditions.
• Comparison Operators: ==, ===, !=, !==, >, <, >=, <=.
• Logical Operators: &&, ||, ! for complex conditions.
• Assertions: Validating expected vs. actual test results.

Example:

let actual = "Login Successful";
let expected = "Login Successful";
console.assert(actual === expected, "Test failed: Login output mismatch");

Pro Tip: Use strict equality (===) to avoid unexpected type coercion.

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Lesson 4: Practical Exercises – Building Simple QA Scripts with JavaScript Control Flow

Concept:
Applying control flow concepts to build functional test automation scripts.

Key Topics:

• Script Planning: Designing a test case scenario.
• Implementing Conditionals: Using if-else in scripts.
• Adding Loops: Automating repetitive test steps.
• Assertions: Validating expected outcomes.
• Testing and Refinement: Running and improving test scripts.

Example:

function runTest(caseName, expectedOutcome) {
    let actualOutcome = performTest(caseName);
    if (actualOutcome === expectedOutcome) {
        console.log(`${caseName} test passed.`);
    } else {
        console.error(`${caseName} test failed.`);
    }
}

runTest("Login", "Success");

Pro Tip: Always log test results clearly for easier debugging and reporting.

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Conclusion

This module covered JavaScript control structures, including conditional statements, loops, and boolean logic, which are essential for writing effective and efficient automated test scripts.

Key Takeaways:

• Conditional statements help automate decision-making in test cases.
• Loops streamline repetitive tasks, reducing manual effort.
• Boolean logic and assertions validate expected outcomes.
• Writing structured test scripts improves maintainability and debugging.

What’s Next?
In the next module, we will dive into Data Structures in JavaScript – Organizing Test Data Effectively, where we will explore arrays, objects, maps, and sets for handling test data efficiently.

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