How to add unit testing in strapi version 4 using jest? - node.js

Question

I'm trying to add unit testing on a brand new strapi application. The official documentation is still in progress. So, until the documentation is being ready is there a way to add jest unit testing to strapi application ? i followed the approach in the v3 documentation with no luck.

Answer 1

There are quite a few changes from Strapi V3 to Strapi V4 when it comes to initializing a Strapi application's APIs. The most important changes are how Strapi populates the KOA routes, and how to make requests to the http server.
To populate the KOA routes use
await instance.server.mount();
instead of
await instance.app
.use(instance.router.routes()) // populate KOA routes
.use(instance.router.allowedMethods()); // populate KOA methods
instance.server = http.createServer(instance.app.callback());
To call the http server use
strapi.server.httpServer
instead of
strapi.server
You also need to use the new database configuration schema when defining your test database. You can use the following as an initial setup for your tests.
The following is an updated (and WIP) guide based on Strapi V3 Unit Testing guide.
First run
yarn add --dev jest supertest sqlite3
or
npm install --save-dev jest supertest sqlite3
Then add the following to your ./package.json scripts:
"scripts": {
// ...strapi scripts
"test": "jest --forceExit --detectOpenHandles", //add
"watch": "yarn test --watch", // optional
}
Then add the following files:
./jest.config.js
module.exports = {
verbose: true,
testPathIgnorePatterns: [
"/node_modules/",
".tmp",
".cache"
],
modulePaths: [
"/node_modules/",
],
testEnvironment: "node",
};
./config/env/test/database.json
{
"connection": {
"client": "sqlite",
"connection": {
"filename": ".tmp/test.db"
},
"useNullAsDefault": true,
"pool": {
"min": 0,
"max": 1
}
}
}
./tests/helpers/strapi.js
const Strapi = require("#strapi/strapi");
const fs = require("fs");
let instance;
async function setupStrapi() {
if (!instance) {
await Strapi().load();
instance = strapi;
await instance.server.mount();
}
return instance;
}
async function cleanupStrapi() {
const dbSettings = strapi.config.get("database.connection");
const tmpDbFile = dbSettings.connection.filename
//close server to release the db-file
await strapi.server.httpServer.close();
//delete test database after all tests
if (dbSettings && tmpDbFile) {
if (fs.existsSync(tmpDbFile)) {
fs.unlinkSync(tmpDbFile);
}
}
// close the connection to the database
await strapi.db.connection.destroy();
}
module.exports = { setupStrapi, cleanupStrapi };
Note that you need to have the /hello endpoint in your project as specified in the strapi docs for the next tests to pass.
./tests/app.test.js
const { setupStrapi, cleanupStrapi } = require("./helpers/strapi");
jest.setTimeout(15000);
beforeAll(async () => {
await setupStrapi();
});
afterAll(async () => {
await cleanupStrapi();
});
it("strapi is defined", () => {
expect(strapi).toBeDefined();
});
require('./hello')
./tests/hello/index.js
const request = require('supertest');
it('should return hello world', async () => {
await request(strapi.server.httpServer)
.get('/api/hello')
.expect(200) // Expect response http code 200
});
I hope this helps anyone struggling with the same issues. I will update the answer as I progress.