Rails best practices.md

• Check the return value of "save", otherwise use "save!" The same goes for create & update.
• Never use has_and_belongs_to_many—use has_many :through instead. The first one has unexpected hidden behaviors and, if you find out that you need an extra column in the intermediate table, converting it to the second macro requires a fair amount of work.
• Never rescue the Exception class
• Use ENV.fetch for environment variables instead of ENV[]so that the unset environment variables are detected on deploy.
• Avoid bypassing validations with methods like save(validate: false), update_attribute, update_column, update_columns, and toggle.
• Don't change a migration after it has been merged into master if the desired change can be solved with another migration.
• Don't reference a model class directly from a view.
• Don't use instance variables in partials. Pass local variables to partials from view templates.
• If there are default values, set them in migrations.
• Validate the associated belongs_to object (user), not the database column (user_id).
• Use private instead of protected when defining controller methods.
• Name date columns with _on suffixes.
• Name datetime columns with _at suffixes.
• Name time columns (referring to a time of day with no date) with _time suffixes.
• Name initializers for their gem name.
• Order ActiveRecord associations above ActiveRecord validations.
• Order the controller contents: filters, public methods, private methods.
• Order i18n translations alphabetically by key name.
• Put application-wide partials in the [app/views/application] directory.
• Use the default render 'partial' syntax over render partial: 'partial'.
• Avoid the :except option in routes. Use the :only option to explicitly state exposed routes.
• Use the user's name in the From header and email in the Reply-To when delivering an email on behalf of the app's users
• Don't use before_actions for setting instance variables. Use them only for changing the application flow, such as redirecting if a user is not authenticated.