# Frontend Development Guidelines

This document describes various guidelines to ensure consistency and quality
across GitLab's frontend team.

## Overview

GitLab is built on top of [Ruby on Rails][rails] using [Haml][haml] with
[Hamlit][hamlit]. Be wary of [the limitations that come with using
Hamlit][hamlit-limits]. We also use [SCSS][scss] and plain JavaScript with
modern ECMAScript standards supported through [Babel][babel] and ES module
support through [webpack][webpack].

We also utilize [webpack][webpack] to handle the bundling, minification, and
compression of our assets.

Working with our frontend assets requires Node (v4.3 or greater) and Yarn
(v0.17 or greater).  You can find information on how to install these on our
[installation guide][install].

[jQuery][jquery] is used throughout the application's JavaScript, with
[Vue.js][vue] for particularly advanced, dynamic elements.

### Browser Support

For our currently-supported browsers, see our [requirements][requirements].

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## [Architecture](architecture.md)
How we go about making fundamental design decisions in GitLab's frontend team
or make changes to our frontend development guidelines.

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## [Testing](testing.md)
How we write frontend tests, run the GitLab test suite, and debug test related
issues.

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## [Design Patterns](design_patterns.md)
Common JavaScript design patterns in GitLab's codebase.

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## [Vue.js Best Practices](vue.md)
Vue specific design patterns and practices.

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## Style Guides

### [JavaScript Style Guide](style_guide_js.md)

We use eslint to enforce our JavaScript style guides.  Our guide is based on
the excellent [Airbnb][airbnb-js-style-guide] style guide with a few small
changes.

### [SCSS Style Guide](style_guide_scss.md)

Our SCSS conventions which are enforced through [scss-lint][scss-lint].

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## [Performance](performance.md)
Best practices for monitoring and maximizing frontend performance.

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## [Security](security.md)
Frontend security practices.

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## [Accessibility](accessibility.md)
Our accessibility standards and resources.


[rails]: http://rubyonrails.org/
[haml]: http://haml.info/
[hamlit]: https://github.com/k0kubun/hamlit
[hamlit-limits]: https://github.com/k0kubun/hamlit/blob/master/REFERENCE.md#limitations
[scss]: http://sass-lang.com/
[babel]: https://babeljs.io/
[webpack]: https://webpack.js.org/
[jquery]: https://jquery.com/
[vue]: http://vuejs.org/
[airbnb-js-style-guide]: https://github.com/airbnb/javascript
[scss-lint]: https://github.com/brigade/scss-lint
[install]: ../../install/installation.md#4-node
[requirements]: ../../install/requirements.md#supported-web-browsers