Write Some Tests (TypeScript)

Testing in TypeScript is almost as easy as with JavaScript. You just need to install a few additional packages.

npm i -D jest @types/jest ts-jest

Then configure Jest to use the ts-jest plugin.

npx ts-jest config:init

This will create a jest.config.js. This file configures Jest to use the preset ts-jest to run tests in Node.

Open up your package.json file and modify your test script.

"scripts": {
    "test": "jest"

Then you can run tests using npm test. When you try that now, you will get an error. No tests were found! So write one.

Create a new folder called src. Then create a subfolder called shared. We put code here that can be used by either the client or the server. Inside of this folder, create a file called model.test.ts:

import { Jinaga, JinagaTest } from "jinaga";

var j: Jinaga;

beforeEach(() => {
    j = JinagaTest.create({});

test("Can create a fact", async () => {
    const firstFact = await j.fact({
        type: "MyApplication.FirstFact",
        identifier: "my_fact_id"


You import JinagaTest so that you can initialize an instance of the Jinaga class. Since you are using TypeScript, you also import Jinaga so that you have the type information.

Every test is going to have the same structure. Inside of beforeEach, you create an instance of Jinaga using the JinagaTest factory. You can then add facts, run queries, and perform all of the other operations in a testing sandbox.

You can run your new test with npm test.

When you build your project, TypeScript will also build your tests. You might not want this. To exclude tests from the build, add an exclude section to tsconfig.json:

    "exclude": [

Continue With

Create Related Facts