I have a react app and I don't know why I don't need to require the jest module.
import Task from './Task';
describe('class Task', () => {
it('inProgress()', () => {
var t = new Task("prova");
expect(t.isInProgress()).not.toBeTruthy();
});
});
The test command for create-react-app runs react-scripts test --env=jsdom.
The script for react-scripts test requires jest on this line and after configuring everything it runs jest on this line.
jest then finds your test files, loads them, and runs them.
In other words, your tests don't load and run jest, it's jest that loads and runs your tests.
Since your tests run within jest they can take advantage of the globals, expect, environment, etc. provided by jest without having to "require or import anything to use them".
Related
I would like to know if it is possible to execute something if all my test files have passed with mocha.
Below: is my index.js file which is run by mocha (in order to get the order I want)
require('dotenv').config();
const logger = require('../toolkits/logger');
//silent mode for testing
logger.transports.forEach((t) => (t.silent = true));
require("./broker.test");
require("./mongo.test");
require("./auth.test");
require("./meal.test");
require("./bowl.test");
I want to process.exit(0) if the tests passed (to integrate it into gitlab CI).
I succeded in check if a test hasn't passed by doing this :
afterEach(function(){
if (this.currentTest.state === "failed")
process.exit(1);
})
But I can't detect if all the tests passed.
I can't just process.exit(0) after requiring all the tests because some of them are asynchronous.
Do you have an idea how I can do that?
! Update !
I found out that I could pass the --exit argument when running mocha from npm :
mocha file --exit
I have an Express.JS server which uses jest and supertest as a testing framework.
It has been working excellently.
When I call my test npm script, it runs npx jest and all of my test files run in parallel.
However I ran my tests recently and they ran sequentially which takes a very long time, they have done this ever since.
I haven't changed any jest or npm configuration, nor have I changed my test files themselves.
Has anyone experienced this? Or is it possible that something in my configuration is incorrect?
jest.config
export default {
setupFilesAfterEnv: ['./__tests__/jest.setup.js'],
}
jest.setup.js
import { connectToDatabase } from '/conn'
// Override the dotenv to use different .env file
require('dotenv').config({
path: '.env.test',
})
beforeAll(() => {
connectToDatabase()
})
test('', () => {
// just a dummy test case
})
EDIT: Immediately after posting the question, I re ran the tests and they ran in parallel, without me changing anything. If anyone has any knowledge around this i'd be interested to get a second opinion
After intermittent switching between parallel and sequential for unknown reasons. I have found it work consistently by adding the --no-cache arg to the npx jest call.
See below where I found the answer
Github -> jest not always running in parallel
I have unit tests and integration tests that need to be run with one 'npm run mocha' command. The suite before my integration tests was set up and working properly with mocha.opts including the before step like so:
test/beforeTests.js (sets up some important variables)
test/*.x.js (bulk of the tests, all the files ending in .x.js are run)
When including my integrations tests, a unit test fails because the running server clashes with some stubbed functions. Therefore I wanted to run unit tests first, then star the server, run integration tests and close the server. Which I have tried by changing mocha.opts to:
test/beforeTests.js (sets up some important variables)
test/*.x.js (bulk of the tests, all the files ending in .x.js are run)
test/startServer.js (start the server)
test/integration/*.x.js (run integration tests)
test/afterTests.js (close the server)
beforeTests.js:
before(function(done) {
// do something
});
startServer.js:
before(function() {
return runServer()
});
both beforeTests, and startServer work however they are both executed in the beginning of the test instead of
beforeTest > do unit tests > start server > do integration tests > stop server
I cannot merge the integration tests in one file, or the unit tests as there are too many. Is there a way to set up mocha.opts to do what I want. I've looked around and nothing really fits what I want to do.
One of technique that I use before for this is to have two npm commands for unit and integration test then combine them in one npm command if I want to run them in single execution.
"test": "npm run test:unit && npm run test:integration"
"test:unit": "mocha test/unit",
"test:integration": "mocha test/integration"
You can start server as part of integration test.
I suggest to use test for npm test instead of mocha for npm run mocha because it is more standard test command name in node project.
Hope it helps
Jest provides some useful methods for executing something before your tests: beforeEach() and beforeAll(). Jest docs on setup
The issue with these is they can only be placed inside of a describe block. So if I have many files, each with their own describe block, I need to place to beforeEach() in every file.
How can I run some code before & after every test, while only adding it once (instead of adding it in every describe block)?
You can try the globalSetup Jest config key. It is an optional key and it can be used to run an async function once before all test suites.
Please see https://github.com/facebook/jest/blob/master/docs/Configuration.md#globalsetup-string
Example of setting up globalSetup in package.json:
jest: {
globalSetup: "./path-to-global-setup.js"
}
... or in jest.config.js:
module.exports = {
globalSetup: "./path-to-global-setup.js"
};
Example of global-setup.js file:
module.exports = async function() {
// do something
};
This file will not be transformed by babel when you run your test suite.
I use Jest to do unit test in node.
And I use the new feature globalSetup which come in Jest v22.
I have defined a global variable in globalSetup.
But I can't get it in the test code. Console log is undefined.
Anyone in this question?
Thanks.
Jest version: 22.0.0
node version: 8.9.0
yarn version: 1.3.2
OS: mac High Sierra 10.13.2
The code as follow:
// package.json
{
"jest": {
"globalSetup": "<rootDir>/src/globalSetupTest.js"
}
}
// globalSetupTest.js
module.exports = async function() {
global.foo = 'foo';
console.log(`global setup: ${global.foo}`);
};
// App.test.js
describe('APP test', () => {
it('renders without crashing', () => {
console.log({ foo: global.foo });
});
});
// test result
yarn run v1.3.2
$ node scripts/test.js --env=node --colors
global setup: foo
PASS src/App.test.js
APP test
✓ renders without crashing (5ms)
console.log src/App.test.js:3
{ foo: undefined }
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 0.354s, estimated 1s
Ran all test suites.
There's a solution offered from Jest people themselves: https://jestjs.io/docs/en/puppeteer.html. Note that if you're using CRA, this won't work out of the box (solution below), cause it currently doesn't support testEnvironment option for Jest.
Anyways:
In Jest config file you setup paths to global setup, teardown and test environment scripts
In global setup script, you create a browser and write it's WSEndpoint to a file
In global teardown script, you simply close the browser
In testEnvironment script, you read WSEndpoint from the file you saved before and then use it to connect to the running browser - after this, browser is available in your tests by using a global variable
If you're using CRA, you can use a custom setup for these tests and run them completely separately. And if you're using Puppeteer for e2e tests, this is probably what you want to do anyway.
You just add another script to your package.json: "test:e2e": "jest -c ./jest-e2e.config.js" and set it up as you want. Now you will have npm run test for unit tests and npm run test:e2e for end to end tests.
For what I understood is a design decision of Jest because is considered a bad practice to share state across different tests. Tests run in parallel and they should keep their own state.
See:
https://github.com/facebook/jest/issues/6007#issuecomment-381743011
https://github.com/facebook/jest/issues/4118
Can you try..
global.foo = 'foo';
console.log(`global setup: ${global.foo}`);
(remove the exports)
You can try changing globalSetup to setupFiles. That one, won't expect a function.
https://facebook.github.io/jest/docs/en/configuration.html#setupfiles-array