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Why we Go with jest

Favor for Jest: Speed and Performance

Against Mocha: Sequential Test Execution

Jest:

Jest runs tests in parallel by default, making it significantly faster for large test suites. It also uses intelligent test caching to minimize unnecessary test runs.

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What's Requirement in our Buy Crypto Module

Given our project's requirements, where speed and performance are critical, and considering we're working on a Node.js backend with functional testing for cron jobs, schedulers, and heavy functions interacting with APIs and databases, let's dive deeper into the specifics of using Jest and Mocha/Chai for such a setup.

Jest for Node.js Backend Testing

Advantages:

1. Speed and Performance: Jest's parallel test execution and intelligent test caching can significantly reduce the time taken to run a large number of tests. This can be crucial for a project with extensive backend functionalities.
2. Built-in Mocking: Jest provides built-in mocking capabilities, which can simplify testing interactions with APIs and databases.
3. Ease of Setup: Jest’s all-in-one nature means we can quickly set up and start writing tests without worrying about integrating multiple libraries.

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Jest Vs Mocha Choose Acoording to need

When deciding between Jest and Mocha/Chai for testing in a Node.js environment, it's important to consider various factors such as speed, complexity, ease of integration, community support, and specific project requirements. Below is a detailed comparison to help us make an informed decision:

Jest

Pros:

1. Simplicity and Integration: Jest is an all-in-one solution. It comes with a test runner, assertion library, and mocking functionality built-in. This reduces the need for additional configuration and integration of multiple libraries.
2. Speed: Jest is known for its performance. It runs tests in parallel and uses intelligent test caching to optimize test execution time.
3. Snapshot Testing: Jest supports snapshot testing out of the box, which is particularly useful for testing React components and ensuring the UI does not change unexpectedly.

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Comprehensive Guide to Node.js Unit Testing

Unit testing is a crucial practice in software development that ensures individual components of an application work as expected. This guide covers everything know about unit testing in Node.js, including a comparison between Mocha/Chai and Jest, and information on additional useful packages like Nock, Sinon, Mocha Awesome, NYC, and Chai-HTTP.

Why Unit Testing is Necessary

1. Early Bug Detection

Unit testing helps identify issues early in the development cycle when they are easier and cheaper to fix. By writing tests for each unit of code, you can catch bugs as soon as they are introduced, preventing them from propagating to other parts of the application.

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Introduction

This project implements a dynamic file upload and serving mechanism based on the user's internet speed. It uses Node.js for the server-side logic and Angular for the client-side logic. The server utilizes speedtest-net to check the user's internet speed in real-time and express-fileupload for file uploads. Files are compressed using sharp and then uploaded to AWS S3 using the aws-sdk. The client-side logic determines the appropriate file version to serve based on the user's internet speed.

Package used

• SHARP for compress image
• speedtest-net for realtime speed check
• express-fileupload
• aws-sdk