Javascript Style Guide

The Ripple Labs style guide is defined by the eslintrc file in this repository along with the supplemental rules listed below.

Additional Rules not covered by ESLint

• Declare variables in the deepest possible block and as close to their use as possible (the linter will catch issues with hoisting)
• Use soft tabs set to 2 spaces
• Use a leading underscore _ when naming private properties
• Use stack.push(x) instead of stack[stack.length] = x
• Copy arrays with Array.slice
• Convert array-like objects to arrays with Array.prototype.slice.call(arguments)
• Strings longer than 80 characters should be written across multiple lines using string concatenation.
• Never name a parameter arguments, this will take precedence over the arguments object that is given to every function scope.
• Assign methods to the prototype object, instead of overwriting the prototype with a new object. Overwriting the prototype makes inheritance impossible: by resetting the prototype you'll overwrite the base!
• When attaching data payloads to events (whether DOM events or something more proprietary like Backbone events), pass a hash instead of a raw value. This allows a subsequent contributor to add more data to the event payload without finding and updating every handler for the event. For example, instead of:

Editor Configuration

It is recommended that you configure your text editor to show linter errors while you are typing.

Sublime Text 3

Note that Sublime Text can optionally be configured for vim or emacs key bindings.

• Copy eslintrc to ~/.eslintrc
• Install Package Control
• Install SublimeLinter
• Install SublimeLinter-contrib-eslint

Jetbrains products (IDEA, WebStorm)

https://www.jetbrains.com/webstorm/help/eslint.html

• npm install -g eslint
• Enable ESLint from File > Settings > Languages and Frameworks > JavaScript > Code Quality Tools > ESLint
• Point "ESLint package" to the installed eslint (osx default /usr/local/lib/node_modules/eslint)

TODO: Write ESLint rules for

• Never name a parameter arguments
• Never assign <Function>.prototype = ...
• Warn when a variable is explicitly re-assigned

Resources

The rules in the previous section are from the Airbnb Style Guide