Guidelines for JavaScript Projects
==================================

Described here are best practices for structuring a JavaScript project within
Kids First.

Version
-------

Any Node.js releases former than 8.0.0 are becoming increasingly deprecated,
only Node.js 8.0.0 and later should be used for Kids First projects.
For the release and maintenance schedule, see `here <https://github.com/nodejs/Release>`_.

Transpile
---------

`V8 <https://v8.dev/>`_ is a widely used JavaScript engine but an assumption
every end-user consumes Kids First products on this particular version should
not be made.
This guide assumes `Babel <https://babeljs.io/>`_ is used for transpiling
source code, and requires
`@babel/preset-env <https://github.com/babel/babel/tree/master/packages/babel-preset-env>`_
or the equivalent toward that end.

Code Standards
--------------

ECMAScript 5 is becoming deprecated and ECMAScript 6+ (ES 2015+) should be
used.
Use the `Airbnb JavaScript Style Guide <https://github.com/airbnb/javascript>`_
for general guidelines around styling and code. This will be used in
conjunction with Prettier for direct linting. In cases of conflict between
the Airbnb JavaScript Style Guide and Prettier, we will default to Prettier.

Prettier
--------

Prettier should be used to provide consistent formatting across the project.
The following is the settings used for prettier that should be stored in
`prettier.config.js` in the root of the project directory:

.. code-block:: js

    module.exports = {
      printWidth: 80,
      singleQuote: true,
      trailingComma: 'all',
      bracketSpacing: false,
    };

Package Management
------------------

Kids First uses ``yarn`` for reliable and secure dependency management of its
JavaScript projects.
All projects should include a ``package.json`` file for easy installation.
``yarn.lock`` also needs to be included to facilitate greater
visibility of tree changes through readable source control differences.

Testing
-------

Kids First requires unit testing to validate that each component of software
performs as designed.
Any unit testing framworks such as
`mocha <https://www.npmjs.com/package/mocha>`_ or the equivalent should run
tests stored in an appropriate directory.


Test coverage can be integrated into each GitHub repos with `Codecov.io <https://docs.codecov.io/docs/node>`_
by installing `codecov <https://github.com/codecov/example-node>`_.