How to do unit testing on node.js web application in visual studio?

You can set up unit testing in Visual Studio for a Node.js project. Here are the steps you can follow:

1. Choose a Test Framework: Visual Studio supports several JavaScript frameworks for unit testing, including Mocha, Jasmine, Tape, and Jest. You can choose the one that best suits your needs.
2. Install the Test Framework: Before adding unit tests to your project, make sure the framework you plan to use is installed locally in your project. This can be done using the npm package installation window.
3. Configure the Test Framework in Visual Studio: In Solution Explorer, right-click the project and choose Edit Project File. Make sure that the following properties are present in the .esproj file with the values shown:

<PropertyGroup>
  <JavaScriptTestRoot>src\\</JavaScriptTestRoot>
  <JavaScriptTestFramework>Jest</JavaScriptTestFramework>
</PropertyGroup>

This example specifies Jest as the test framework. You could specify Mocha, Tape, or Jasmine instead¹. The JavaScriptTestRoot element specifies that your unit tests will be in the src folder of the project root.

1. Install npm Packages: In Solution Explorer, right-click the npm node and choose Install new npm packages. Use the npm package installation dialog to install the following npm packages: jest, jest-editor-support. These packages are added to the package.json file under dependencies.
2. Add Test Section in package.json: In package.json, add the test section at the end of the scripts section:

"scripts": {
  ...
  "test": "jest"
},

1. Add a Unit Test File: In Solution Explorer, right-click the src folder and choose Add > New Item, and then add a new file named App.test.tsx. This adds the new file under the src folder. Add the following code to App.test.tsx:

describe ('testAsuite', () => {
  it ('testA1', async () => {
    expect (2).toBe (2);
  });
});

1. Run the Tests: You can run the tests from the Test Explorer in Visual Studio. If you don’t already have Test Explorer open, you can find it by selecting Test > Test Explorer in the menu bar¹. To run unit tests from the command-line, right-click the project in Solution Explorer, choose Open in Terminal, and run the command specific to the test type.

I hope this helps