Protractor E2E Testing Error: Cannot find module 'selenium-webdriver' - angularjs

Question

Error: Cannot find module 'selenium-webdriver'
I have installed protractor and selenium-webdriver globally using npm install -g protractor webdriver-manager update
var webdriver = require('selenium-webdriver');
describe('modes of failure', function() {
it('should fail to find a non-existent element', function() {
browser.get('index.html#/form');
// Run this statement before the line which fails. If protractor is run
// with the debugger (protractor debug debugging/conf.js), the test
// will pause after loading the webpage but before trying to find the
// element.
browser.debugger();
// This element doesn't exist, so this fails.
var nonExistant = element(by.binding('nopenopenope')).getText();
});
it('should fail to use protractor on a non-Angular site', function() {
browser.get('http://www.google.com');
}, 20000);
it('should fail an assertion', function() {
browser.get('index.html#/form');
var greeting = element(by.binding('{{greeting}}'));
expect(greeting.getText()).toEqual('This is not what it equals');
});
});

Answer 1

You need to install the node module:
npm i selenium-webdriver --save-dev

Answer 2

Did you try to remove the var webdriver = require('selenium-webdriver'); ?
You shouldn't need it, you can access it in your test via browser
browser this is the a wrapper around an instance of webdriver. Used for navigation and page-wide information.
(quoted from Getting started - Protractor docs)
If you've already installed the Selenium standalone server using webdriver-manager update, and started it with webdriver-manager start, all you have to do is to run your tests using
protractor path/to/your/protractor-conf.js

Answer 3

When you type:
webdriver-manager
Into the terminal, the these helpful options appear:
webdriver-manager
Usage: webdriver-manager <command>
Commands:
update: install or update selected binaries
start: start up the selenium server
status: list the current available drivers
Have you tried update, start, or status?

Answer 4

Try using the standalone option:
$ webdriver-manager start --standalone