JS.md

JS conventions (draft)

This document outlines the conventions we have at MetaStudio for writing JavaScript code.

We always use pure JavaScript.

Derived from

• http://contribute.jquery.org/style-guide/js/
• http://javascript.crockford.com/code.html
• https://github.com/rwaldron/idiomatic.js

Idiomatic JS

This part is largely taken from https://github.com/necolas/idiomatic-css

• Indentation : 2 spaces
• Line length : 80 columns
• Whitespaces : configure your editor to "show invisibles" or to automatically remove end-of-line whitespace.
• No whitespace at the end of line or on blank lines
• Never mix spaces and tabs
• if/else/for/while/try always have braces and always go on multiple lines.
• Unary special-character operators (e.g., !, ++) must not have space next to their operand.
• Any , and ; must not have preceding space.
• Any ; used as a statement terminator must be at the end of the line.
• Any : after a property name in an object definition must not have preceding space.
• The ? and : in a ternary conditional must have space on both sides.
• No filler spaces in empty constructs (e.g., {}, [], fn())
• New line at the end of each file.

Bad example

// Bad
if(condition) doSomething();
while(!condition) iterating++;
for(var i=0;i<100;i++) object[array[i]] = someFn(i);

Goog example

var i = 0;

if ( condition ) {
  doSomething();
} else if ( otherCondition ) {
  somethingElse();
} else {
  otherThing();
}

while ( !condition ) {
  iterating++;
}

for ( ; i < 100; i++ ) {
  object[ array[ i ] ] = someFn( i );
}

try {
  // Expressions
} catch ( e ) {
  // Expressions
}

TODO:

• Unobtrusive JS - use classes