Frontend Style Guide by Kaliop

General Rules

Maintain a README file

  • Every project should have a file (or just README).
  • Every developer should read this file, and update it if needed.
  • Use Markdown syntax for better readability in Bitbucket, GitHub, etc.

This should exist at the root of the repository and give information on:

  1. What the project is (client, site/app name)
  2. How to install the project on a developer’s machine
  3. How to run development tasks (e.g. import data, compile frontend assets)
  4. How to deploy the project

If this documentation gets too big, you can break it into several files for specialized topics:

Finally, if you set up a project from a boilerplate, and that boilerplate already has its own README file, see if you can remove it or rename it.

Use EditorConfig

Frontend code files should be:

  • encoded as UTF-8,
  • with LF end of lines,
  • and spaces for indents.

We use the EditorConfig format to harmonize indentation and file format in a project. For this to work, we need two things:

  1. A .editorconfig file at the root of each project.
  2. Your editor or IDE should have an EditorConfig plugin.

Please verify both points now if you’re not sure.
There are EditorConfig plugins for most code editors:

Here’s a reference .editorconfig file for new projects:

root = true

charset = utf-8
end_of_line = lf
indent_style = space
indent_size = 2

indent_size = 4

Use the DRY principle

Don’t Repeat Yourself: avoid code that is very similar in different places in the project.

In particular, avoid copying and pasting code in different places! Duplicated code is hard to maintain: you have to do the changes in 2, 5 or 10 places, and test each change.

  • Templating: use includes, partials, macros…
  • Styles: use components, utility classes, mixins…
  • JavaScript: use functions, modules, components…

This is not an absolute rule! For example, if you need to make a variant that can evolve without impacting the first feature, some copy-pasting can be justified.

Clean up your code

Keep the codebase short and avoid unused code.

  • Remove unused files, failed experiments, etc.
  • HTML: avoid unnecessary elements and attributes
  • CSS: avoid unused selectors, and useless properties
  • JS, PHP, etc.: look out for unused variables and functions