Develop Reference

React / Jest get coverage from a single component not all - current approach not working

I have tried this answer to get coverage for a single component but it is not working. The test runs only for that component but no coverage?
Is there some other configuration that needs to be done anywhere?
I have tried:
npm test src/components/component1/my-component.test.tsx --coverage --collectCoverageFrom=src/components/component1/my-component.test.tsx
Anything I am doing wrong?

The collectCoverageFrom takes in glob patterns as argument, so you need adjust that path string with "".
I have successfully run this command with code coverage from one file with
node_modules/.bin/jest ComponentTest.test.ts --coverage --collectCoverageFrom="path/Component.tsx"
It also it may be that your "test" cmd you are running from package.json is obscuring the additional arguments, try directly calling jest from modules to see if thats the case.

This worked to me with create-react-app from windows cmd:
npx react-scripts test src/components/common/__test__/Dropdown.test.tsx --coverage --collectCoverageFrom=src/components/common/Dropdown.tsx

how to use testNamePattern of jest within package.json scripts field?

Honestly, jest of facebook has a bad document.
I want to use jest -t xxx to update my snapshots.
Here is my test, but no one works correctly.
jest -u -t='test.tsx'
jest -u -t 'test.tsx'
jest -u -t /test.tsx/
jest -u -t=/test.tsx/
I want to match and update snapshots test files which filename pattern like *.test.tsx.
How can I do that with jest testNamePattern?

First check jest --showConfig to see that you even have the option of --testNamePattern. I faced the same issue, and did not find this option in jest config.
So I changed my directory structure and used --testPathPattern option with regex. This works.
jest --testPathPattern='(tests)/spec/./snapshot-tests/.'

JsPsych What kind of unit tests are these? Javascript

I'm working on an existing project but I am new to Javascript. The project can be found here, it is JsPsych and I've searched the documentation here and cannot find the answer (http://docs.jspsych.org/)
I don't understand how they are doing unit tests. I have found the "testing" folder and you can view it below, here.
JsPsych test folder
Here's an example called "load.test.js"
const root = '../';
require(root + 'jspsych.js');
require(root + 'plugins/jspsych-single-stim.js');
test('jsPsych should be in the window object', function(){
expect(typeof window.jsPsych).not.toBe('undefined');
});
Does anyone recognize this type of unit test? Is this supposed to be paired with some software? Can someone explain how I would actually run this?

The tests are run with Jest. You can see that jest is called as the test command in package.json.
To run the tests, install node and npm on your system. Then run npm install in the repository's main directory. Then you can run npm test.

How to run specific tests with frisby?

We are using frisby to run our integration tests and while developing them, it would be handy to execute one specific one or a group of tests, without having run all of them and see extra noise. Right now I am commenting out all the ones I don't want to run, which is getting tedious.
Is there a way, from the command line, to run specific frisby tests?
So basically, instead of
npm test
I want to be able to say
npm test --name: posts
Or something like that. I found this post about jasmine-only, but I'm not sure it will satisfy my needs.
Thanks so much!

I'm not sure if you're still looking for answer, but this is pretty simple.
Firstly install latest version of jasmine-node from command line: npm install jasmine-node -g
Then to run particular test use: jasmine-node --coffee putTestNameHere

Install jasmine-node module. Execute one file at a time - you can group your test cases in specific file:
jasmin-node moduleTestCases_spec.js
Also, if you want to specify exact test case name to be executed, you can make use of sequenty module. It is a nodejs module, which you can specify the order(and thus the exact test cases to execute).

To run specific test in Frishby just run:
npm test ./folder/filename.js
So lets assume you have an folder say test under that you have a file called api.spec.js
then you will execute like this:
npm test ./test/api.spec.js
Parallely don't forget to specify these below things into your package.json file
"scripts": {
"test": "mocha" }

Run and add unit tests to nodejs project

I want to run the tests related to this project on github, see folder test on https://github.com/node-opcua/node-opcua . Unfortunately I have no idea which testing framework was used and how to run all the tests?

First, run npm install
This will install the required dependencies.
You can then use
npm test
See here:
https://github.com/node-opcua/node-opcua/blob/master/package.json#L15
That will run the tests using Mocha.