Basic testing

[ElenaDatso]

Basic testing

Prerequisites
Install Node.js
Fork this repository: https://github.com/AlreadyBored/basic-testing
Clone your newly created repo locally: https://github.com/<%your_github_username%>/basic-testing/
Go to folder basic-testing
To install all dependencies use npm install
Run test scripts in command line.
You will see the number of skipped, passing and failing tests.
Test scripts

run unit tests

$ npm run test

with logging

$ npm run test:verbose
Notes
We recommend you to use Node.js of version 22.x.x (22.14.0 or upper) LTS. If you use any of features, that does not supported by Node.js 22, there may be problems with task submit.
Please, be sure that each of your tests is limited to 30 sec.
Please, be sure you don't have any linter/TS compiler errors.
General task description
Your task is to write unit tests for code, provided in file index.ts.

Simple tests
Write unit tests for the simpleCalculator function, which performs basic mathematical operations - addition, subtraction, division, multiplication, and exponentiation. Your task is to verify that the operations are executed correctly and that the function returns null for invalid input.

Write your tests in src/01-simple-tests/index.test.ts.

Table tests
Your task is to rewrite the tests written in the previous task using the table-driven testing approach, utilizing the appropriate Jest API.

Write your tests in src/02-table-tests/index.test.ts.

Error handling & async
Your task is to test functions that work asynchronously/throw/reject exceptions..

Write your tests in src/03-error-handling-async/index.test.ts.

Testing class
Your task is to test a class representing a bank account that implements corresponding operations. Please note that some methods of the class invoke others, some operations result in errors, and the implementation is asynchronous and involves the native JS API. These aspects should be taken into account when writing the tests.

Write your tests in src/04-test-class/index.test.ts.

Partial mocking
Your task is to utilize the Jest API to partially mock the contents of a module.

Write your tests in src/05-partial-mocking/index.test.ts.

Mocking Node.js API
Your task is to test the proper usage of the Node.js API based on commonly used APIs such as the fs module, as well as setTimeout and setInterval. Remember that the tests should not interact with the actual file system and should not rely on real-time!

Write your tests in src/06-mocking-node-api/index.test.ts.

Mocking library API
Your task is to test that function that utilize library APIs is working correctly (with commonly used libraries such as axios and lodash as examples).

Write your tests in src/07-mocking-lib-api/index.test.ts.

Snapshot testing
Your task is to use snapshot testing with Jest and compare it to regular comparison testing.

Write your tests in src/08-snapshot-testing/index.test.ts.