Unit testing using Jasmine and TypeScript

Here’s (in my opinion) the best way to test a ts-node app as of 2018:

npm install --save-dev typescript jasmine @types/jasmine ts-node

In package.json:

{
  "scripts": {
    "test": "ts-node node_modules/jasmine/bin/jasmine"
  }
}

In jasmine.json change file pattern to *.ts

"spec_files": ["**/*[sS]pec.ts"],

In your spec files:

import "jasmine";
import something from "../src/something";

describe("something", () => {
    it("should work", () => {
        expect(something.works()).toBe(true);
    });
});

To run the tests:

npm test

This will use the locally installed versions of ts-node and jasmine. This is better than using globally installed versions, because with local versions, you can be sure that everyone is using the same version.

Note: if you have a web app instead of a node app, you should probably run your tests using Karma instead of the Jasmine CLI.