**Course Title:** Testing Frameworks: Principles and Practices **Section Title:** Testing Frameworks Overview **Topic:** Set up a testing environment and run tests using different frameworks. (Lab topic) **Objective:** By the end of this lab topic, students will be able to set up testing environments for popular testing frameworks (Jest, Mocha, JUnit, and NUnit) and run tests using these frameworks. **Introduction:** In this lab topic, we will guide you through setting up testing environments for different testing frameworks and running tests using these frameworks. We will focus on the most popular testing frameworks: Jest, Mocha, JUnit, and NUnit. **Setting up a Testing Environment for Jest:** Jest is a popular testing framework for JavaScript. To set up a testing environment for Jest, follow these steps: 1. Install Node.js and npm from [https://nodejs.org/en/download/](https://nodejs.org/en/download/). 2. Create a new Node.js project using the command `npm init`. 3. Install Jest using the command `npm install --save-dev jest`. 4. Create a new file called `sum.js` with the following code: ```javascript function sum(a, b) { return a + b; } module.exports = sum; ``` 5. Create a new file called `sum.test.js` with the following code: ```javascript const sum = require('./sum'); test('adds 1 + 2 to equal 3', () => { expect(sum(1, 2)).toBe(3); }); ``` 6. Open `package.json` and add the following script: ```json "scripts": { "test": "jest" } ``` 7. Run tests using the command `npm run test`. **Setting up a Testing Environment for Mocha:** Mocha is another popular testing framework for JavaScript. To set up a testing environment for Mocha, follow these steps: 1. Install Node.js and npm from [https://nodejs.org/en/download/](https://nodejs.org/en/download/). 2. Create a new Node.js project using the command `npm init`. 3. Install Mocha using the command `npm install --save-dev mocha`. 4. Create a new file called `sum.js` with the following code: ```javascript function sum(a, b) { return a + b; } module.exports = sum; ``` 5. Create a new file called `sum.test.js` with the following code: ```javascript const assert = require('assert'); const sum = require('./sum'); describe('sum', function() { it('adds 1 + 2 to equal 3', function() { assert.equal(sum(1, 2), 3); }); }); ``` 6. Open `package.json` and add the following script: ```json "scripts": { "test": "mocha" } ``` 7. Run tests using the command `npm run test`. **Setting up a Testing Environment for JUnit:** JUnit is a popular testing framework for Java. To set up a testing environment for JUnit, follow these steps: 1. Install Java Development Kit (JDK) from [https://www.oracle.com/java/technologies/javase/javase-jdk8-downloads.html](https://www.oracle.com/java/technologies/javase/javase-jdk8-downloads.html). 2. Create a new Java project in your preferred IDE. 3. Install JUnit using your IDE's package manager or by downloading the JAR file from [https://junit.org/junit5/](https://junit.org/junit5/). 4. Create a new file called `Sum.java` with the following code: ```java public class Sum { public int calculate(int a, int b) { return a + b; } } ``` 5. Create a new file called `SumTest.java` with the following code: ```java import org.junit.Test; import static org.junit.Assert.assertEquals; public class SumTest { @Test public void testSum() { Sum sum = new Sum(); assertEquals(3, sum.calculate(1, 2)); } } ``` 6. Run tests using your IDE's built-in test runner. **Setting up a Testing Environment for NUnit:** NUnit is a popular testing framework for .NET. To set up a testing environment for NUnit, follow these steps: 1. Install Visual Studio from [https://visualstudio.microsoft.com/downloads/](https://visualstudio.microsoft.com/downloads/). 2. Create a new .NET project in Visual Studio. 3. Install NUnit using NuGet Package Manager. 4. Create a new file called `Sum.cs` with the following code: ```csharp public class Sum { public int Calculate(int a, int b) { return a + b; } } ``` 5. Create a new file called `SumTest.cs` with the following code: ```csharp using NUnit.Framework; [TestFixture] public class SumTest { [Test] public void TestSum() { Sum sum = new Sum(); Assert.AreEqual(3, sum.Calculate(1, 2)); } } ``` 6. Run tests using Visual Studio's built-in test runner. **Conclusion:** In this lab topic, we have set up testing environments for four popular testing frameworks: Jest, Mocha, JUnit, and NUnit. We have also run tests using these frameworks. By following these steps, you can set up your own testing environments and start writing tests for your applications. **Practical Takeaways:** * Set up testing environments for different testing frameworks * Run tests using different testing frameworks * Use popular testing frameworks to write tests for your applications **Key Concepts:** * Testing frameworks * Testing environments * Jest * Mocha * JUnit * NUnit **Do you have any questions or need help with setting up a testing environment? Please feel free to ask in the comments.** **What's Next:** In the next topic, we will cover integration testing and its importance. Integration testing is a software testing technique where individual units of a software are combined and tested as a group. It is used to verify the interactions between different components of a software system.