Unit Testing

TypeScript helps catch bugs before your code runs, but it can't guarantee your logic is correct.

With unit tests, you can:

• Prevent regressions: Catch bugs early before they break your app.
• Refactor with confidence: Change code without worrying about unexpected side effects.
• Verify business logic: Ensure functions return the right results, not just the right types.

By combining TypeScript's static typing with unit tests, you get stronger, more reliable code.

Jest

Jest is a common testing utility.

// Collection of tests in a file
describe('Example tests', () => {
    // Must contain at least one test with any number of assertions
    it('should add numbers', () => {
        expect(1 + 1).toEqual(2)
        expect(2 * 2).toEqual(4)
        // ...
    })
})

Read more on how to set up testing with Jest.

Mocha + Chai

• https://www.testim.io/blog/mocha-for-typescript-testing/

Roll your own tests