Tower Style Guide

General Documentation Semantics

• Write in a conversational style.

  • Use pronouns: I, we, you, they.
  • Use colloquial expressions: a sure thing, turn-on, rip-off, OK.
  • Use contractions: they're, you're, it's, here's, we've, I'm.
  • Use simple words.
  • If you must choose between writing naturally and being grammatically correct, write naturally.

  // yay
  I'm going home.
  It's simple.
  
  // nay
  I am going home.
  It is simple.

JavaScript

• Define var one at a time (don't use leading/trailing commas):

  // yay
  var event = require('event');
  var dom = require('dom');
  var assert = require('assert');
  
  // nay
  var event = require('event'),
      dom = require('dom'),
      assert = require('assert');
  
  // nay
  var event = require('event')
    , dom = require('dom')
    , assert = require('assert');

  While the later two are minimally more optimized, minifiers like uglifyjs will make these optimizations for you. So write what is most human readable.

• Use trailing commas for multi-line arrays.

  // yay
  var events = [
    'click',
    'keypress',
    'focusin',
    'focusout'
  ];
  
  // nay
  var events = [
      'click'
    , 'keypress'
    , 'focusin'
    , 'focusout'
  ];

• Use trailing commas for multi-line objects.

  // yay
  var styles = {
    color: '#000',
    background: '#fff',
    width: 100,
    height: 200
  };
  
  // nay
  var styles = {
      color: '#000'
    , background: '#fff'
    , width: 100
    , height: 200
  };

• Always use " double quotes when declaring JSON keys and values.

  // yay
  {
    "myKey": "string",
    "myArray": ["some stuff", "more stuff"]
  }
   
  // nay
  {
    myKey: 'string',
    'myArray': ['some stuff', 'more stuff']
  }

• For strings that are not defined in JSON, default to declaring strings with ' single quotes. In the case where your string contains special format characters or ' single quotes, use " double quotes.

  // yay
  var str = '"Marty" is at the party!';
  var specialStr = "im'oto";
  
  // nay
  var str = "\"Marty\" is at the party!";
  var specialStr = 'im\'oto';

• For assigned functions, have no whitespace between parentheses and brackets: ){ vs. ) {.

  // yay
  exports.init = function(){
    this.x;
  };
    
  // nay
  exports.init = function() {
    this.x;
  };

• For callback functions, do the same thing.

  // yay
  route('/users')
    .on('exec', function(){
  
    });
    
  // nay
  route('/users')
    .on('exec', function() {
  
    });

• For non-assigned functions, do it the other way around.

  // yay
  function init() {
    this.x;
  };
    
  // nay
  function init(){
    this.x;
  };

  This distinguishes the function declarations and function expressions.

• Indent DSL methods if they are in a new object scope.

  // yay
  adapter('facebook')
    .model('user')
      .attr('username')
      .action('create')
      .action('find')
        .param('page', 'integer')
    .model('like');
    
  // nay
  adapter('facebook')
    .model('user').attr('username').action('create')
    .action('find')
    .param('page', 'integer')
    .model('like');      

• Keep 1 space between native methods and parentheses (if, while, for, etc.).

  // yay
  if (x) y();
  
  // nay
  if(x) y();

• Emit event names in the present tense as verb [object|property].

  // yay
  this.emit('define', user);
  this.emit('define user', user);
    
  // nay
  this.emit('defined user', user);
  this.emit('user defined', user);
  this.emit('user define', user);

• Emit namespaced events from most generic to most specific. This way, you can mixin more generic stuff first, and use those generic methods on specific objects.

  // yay
  this.emit('define', user);
  this.emit('define facebook', user);
  this.emit('define facebook.user', user);
    
  // nay
  this.emit('define facebook.user', user);
  this.emit('define facebook', user);
  this.emit('define', user);

• Pass the this as context for the first parameter in DSL methods, instead of using this as a reference. The context is stated more clearly.

  // yay
  route('/users')
    .on('request', function(context, next){
      context.render();
    });
  
  // nay
  route('/users')
    .on('request', function(next){
      this.render();
    });

• Place the compared value on the left instead of the right. This is unnatural at first, but it makes the code much easier to read for a newcomer.

  // yay
  if ('string' === typeof(x))
    exec();
  
  // nay
  if (typeof(x) === 'string')
    exec();

  The reason for this is, the compared-to value (e.g. 'string') is first, so it reads if ('string') exec().

• Leave 1 empty line at the *top of each file.

  \n
  /**
   * Blank line above.
   */

  /**
   * No blank line above
   */

• Leave 0 empty lines at the bottom of each file.

• Leave 1 blank line between comments and code.

  /**
   * GOOD
   */
  
  exports.init = function(){
  
  };

  /**
   * BAD
   */
  exports.init = function(){
  
  };

• For loops should be as efficient and clean as possible.

  // yay
  for (var i = 0, n = arr.length; i < n; i++) {}
  
  // nay
  for (var i = 0; i < arr.length; i++) {}

  Single letter variables should only be used within loops (basically for loops).

   // yay
   for (var i = 0, n = arr.length; i < n; i++) {}
  
   // nay
   for (var index = 0, size = arr.length; index < size; index++) {}

• For each loops (for loops but with objects) should have safe guards, which is a general good JavaScript practice.

  // yay
  for (var key in obj) {
    if (obj.hasOwnProperty(key)) {
      delete obj[key];
    }
  }
  
  // nay   
  for (var key in obj) {
    delete obj[key];
  }

• Use obj.init() instead of new Obj, where obj.create() should do some db/service call.

  // yay
  var newObj = obj.init();
  
  // nay
  var newObj = new Obj();

• For single-line arrays and objects, put one space before/after containing brackets.

  // yay
  [ 'i386', 'x86_64' ]
  { status: 'active' }
  
  // nay
  ['i386', 'x86_64']
  {status: 'active'}

• Avoid aligning signs such as =, :, etc. The reason is, while it does create some symmetry, it makes the code a little harder to read.

  // yay
  var x = 1;
  var foo = 'bar';
  var hello = 'world';
  
  // nay
  var x     = 1;
  var foo   = 'bar';
  var hello = 'world';

• If a ternary statement is too long, put it on multiple lines with ? and : at the start of the line.

  // yay
  exports.query = function(name){
    return null == name
      ? query().start(this.className)
      : query(name);
  }
  
  // nay
  exports.query = function(name){
    return null == name ?
      query().start(this.className) :
      query(name);
  }

• If you are building a multiline string, use + at the beginning of the line.

  // yay
  var string = 'some '
    + 'long '
    + 'string ';
  
  // nay
  var string = 'some ' +
    'long ' +
    'string ';
  
  // nay
  var string = 'some \
    long \
    string ';

  In EcmaScript 6, you'll be able to use backticks for multi-line strings.

Repos

• Name your projects using lowercase with hyphens.

  // yay
  var myProject = require('my-project');
  
  // nay
  var myProject = require('myProject');
  var myProject = require('MyProject');

Events

These are all of the events used in Tower. When creating custom APIs, see if these events can be used before defining another. Maybe we can even cut it down.

emit('define');
emit('init');
emit('exec');
emit('open');
emit('close');
emit('connect');
emit('disconnect');
emit('render');
emit('request');
emit('error');
emit('data');

Maybe route.on('request') becomes route.on('exec'). And route.on('connect') becomes route.on('open').

Tests

• Use easy to scan/understand syntax for assertions.

  // yay
  assert(true === val);
  assert(false === val);
  assert('foo' === val);
  assert(undefined === val);
  
  // nay
  assert.isTrue(val);
  assert.isFalse(val);
  assert.equal('foo', val);
  assert.isUndefined(val);
  // - should syntax
  val.should.be(undefined);

Comments

• Here is the general structure of a good comment:

  /**
   * Iterate each value and invoke `fn(val, i)`.
   *
   *    users.each(function(val, i){
   *
   *    });
   *
   * @param {Function} fn
   * @return {Object} self
   * @api public
   */
  
  proto.forEach = function(fn){
    // ...
    return this;
  };

Readme Structure

The basic format:

• Title
• Installation
• Examples (optional)
• API
• Running Tests
• Contributing
• Notes (optional)
• License

Examples

• https://github.com/component/struct/blob/master/index.js
• https://github.com/component/pipe/blob/master/index.js
• https://github.com/component/raf/blob/master/index.js
• https://github.com/component/to-function/blob/master/index.js
• https://github.com/component/enumerable/blob/master/index.js
• https://github.com/component/network
• https://github.com/component/trace/blob/master/index.js
• http://stackoverflow.com/questions/5495984/coding-style-guide-for-node-js-apps