Jest with ES6 imports and React

jest-es6-setup.md

Create project and install deps

mkdir hello
cd hello

npm init
...
test command: jest --coverage
...

npm install --save-dev jest babel-jest babel-preset-env babel-preset-react

For more info, see: https://facebook.github.io/jest/docs/en/getting-started.html

Setup ES6 and react

vi .babelrc

{
    "presets": ["env", "react"]
}

Create files as per jest getting started page

vi sum.js

const sum = (a, b) => {
  return a + b;
};
export default sum;

vi sum.test.js

import sum from './sum';

test('adds 1+2 to equal 3', () => {
  expect(sum(1, 2)).toBe(3);
});

Running

jest

or,

npm test

Expected output

 PASS  ./sum.test.js
  ✓ adds 1+2 to equal 3 (2ms)

Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        0.565s, estimated 1s
Ran all test suites.
----------|----------|----------|----------|----------|----------------|
File      |  % Stmts | % Branch |  % Funcs |  % Lines |Uncovered Lines |
----------|----------|----------|----------|----------|----------------|
All files |      100 |      100 |      100 |      100 |                |
 sum.js   |      100 |      100 |      100 |      100 |                |
----------|----------|----------|----------|----------|----------------|

For babel 7, we need to use @babel/preset-env instead of babel-preset-env.
Thanks for the notes. Helped me set testing with Jest in ES6.

Thanks for the tip. I'll make the change