documentation/content/en/dev/code.md

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Code structure	Where to find certain parts of the codebase.	docs weight parent 30 dev

Code structure

The following overview should not be seen as complete or authoritative, but as a rough guidance to help you find your way in the application.

Ruby

app/controllers

Code that binds business logic to templates

app/helpers

Code that can be used from views, i.e. common operations

app/lib

Code that doesn’t fit in the other categories

app/models

Representation of data entities and their associated methods

app/policies

Permission checks and other validations, before calling related methods

app/serializers

Code that generates JSON from models

app/services

Complex logical operations involving multiple models

app/views

Templates for generating HTML or other output

app/workers

Code that executes outside the request-response cycle

spec

Automated test suite

JavaScript

app/javascript/mastodon

Code for the frontend React.js application

app/javascript/packs

Code for non-React.js pages

CSS and other assets

app/javascript/images

Images

app/javascript/styles

Code that turns into CSS via Sass

Localizations

config/locales

Server-side localizations in the YML format

app/javascript/mastodon/locales

Client-side localizations in the JSON format

All locale files are normalized to ensure consistent formatting and key order, which minimizes changesets in version control.

• Run bundle exec i18n-tasks normalize to normalize server-side translations
• Run yarn run i18n:extract to extract and normalize client-side translations into en.json