I've been playing a little bit with Selenium for testing purposes. Here's a tiny example.

Create a package.json file manually or via. npm init. You could run the npm commands separately but why not just run them one time and let npm do the rest. 

{
  "name": "selenium-tests",
  "homepage": "https://engbjerg.dk",
  "version": "1.0.0",
  "private": true,
  "description": "Run tests on [WEBSITE] with selenium",
  "dependencies": {
    "assert": "2.0.0",
    "chromedriver": "^87.0.4",
    "chrome-modheader": "^1.0.6",
    "mocha": "^8.2.1",
    "selenium-webdriver": "^4.0.0-alpha.8"
  },
  "author": "Willam <my@mail>",
  "main": "main.js",
  "devDependencies": {},
  "scripts": {
    "test": "mocha *.js",
    "test-single": "mocha *.js --grep $npm_config_feature"
  }
}
package.json

Write your first script

This hasn't been fully tested. Just an example. 

it('TEST_URL', async function() {
    let link = await driver.wait(until.elementLocated(By.css('button')), 300);
    let clicked = await link.click(); 
    
    assert.strictEqual(await clicked, true, "No click was attempted");
    
});

Execute test-scripts

# Test Commands 

$ npm test FILENAME

# Run a single function from it  

$ npm run test FILENAME --func="TEST_URL"