How to run javascript

Node.js (terminal)

Installing Node

Installing Node by nvm:

$ wget -qO- https://raw.githubusercontent.com/creationix/nvm/v0.33.11/install.sh | bash

Node LTS:

$ nvm install lts
$ nvm alias default lts

Node Stable:

$ nvm install stable
$ nvm alias default stable

Alternatives:

$ choco install nodejs

Running JS

Running by file:

$ node file.js

vscode

Node Prompt:

$ node
> (ctrl + v file)

Running by file (ECMAScript Modules ESM):

$ git clone https://github.com/ifpb/javascript-exercises/
$ cd javascript-exercises/ecma/function/sum/code/
$ mv sum.{js,mjs)
$ node --experimental-modules sum.print.mjs

Visual Studio Code

Installing:

vscode

Browser Console

Control+Shift+J (Google Chrome)
> (ctrl + v file)

Online Interpreter

https://repl.it/

Open [https://repl.it/](https://repl.it/)
> Choose language: Javascript
> (ctrl + v file)
> Click button run

Unit Test (Jest)

Installing Jest (package.json):

$ git clone https://github.com/ifpb/javascript-exercises/
$ cd javascript-exercises/ecma/
$ ls package.json
package.json
$ npm install

Rename file extension to .js:

$ mv function/sum/code/sum.{mjs,js}

Running Tests and Viewing Results (test fail):

$ npx jest function/sum/code/sum.test.js
 FAIL  function/sum/code/sum.test.js
  Number Tools
    ✕ adding 1 + 2 (12ms)
    ○ skipped 1 test

  ● Number Tools › adding 1 + 2

    expect(received).toBe(expected) // Object.is equality

    Expected value to be:
      3
    Received:
      undefined

    Difference:

      Comparing two different types of values. Expected number but received undefined.

      4 |
      5 |   test('adding 1 + 2', () => {
    > 6 |     expect(sum(1, 2)).toBe(3)
      7 |   })
      8 |
      9 |   test.skip('adding 3 + 2', () => {

      at Object.<anonymous> (function/sum/code/sum.test.js:6:23)

Test Suites: 1 failed, 1 total
Tests:       1 failed, 1 skipped, 2 total
Snapshots:   0 total
Time:        2.689s
Ran all test suites matching /code\/function\/sum.test.js/i.

Running Tests and Viewing Results (test passed):

$ npx jest function/sum/code/sum.test.js
 PASS  response/function/sum.test.js
  Number Tools
    ✓ adding 1 + 2 (5ms)
    ✓ adding 3 + 2

Test Suites: 1 passed, 1 total
Tests:       2 passed, 2 total
Snapshots:   0 total
Time:        1.594s
Ran all test suites matching /response\/function\/sum.test.js/i.

Unit Testing