NAME

       npm-coding-style - npm´s "funny" coding style

DESCRIPTION

       npm´s coding style is a bit unconventional. It is not different for difference´s sake, but
       rather a carefully crafted style that is designed to reduce visual clutter and  make  bugs
       more apparent.

       If  you  want  to  contribute to npm (which is very encouraged), you should make your code
       conform to npm´s style.

       Note: this concerns npm´s code not the specific packages at npmjs.org

Line Length

       Keep lines shorter than 80 characters. It´s better for lines to be too short  than  to  be
       too long. Break up long lists, objects, and other statements onto multiple lines.

Indentation

       Two-spaces.  Tabs are better, but they look like hell in web browsers (and on github), and
       node uses 2 spaces, so that´s that.

       Configure your editor appropriately.

Curly braces

       Curly braces belong on the same line as the thing that necessitates them.

       Bad:

           function ()
           {

       Good:

           function () {

       If a block needs to wrap to the next line, use a curly brace. Don´t use it if it doesn´t.

       Bad:

           if (foo) { bar() }
           while (foo)
             bar()

       Good:

           if (foo) bar()
           while (foo) {
             bar()
           }

Semicolons

       Don´t use them except in four situations:

       •   for (;;) loops. They´re actually required.

       •   null loops like: while (something) ; (But you´d better have a good  reason  for  doing
           that.)

       •   case "foo": doSomething(); break

       •   In  front  of  a leading ( or [ at the start of the line. This prevents the expression
           from being interpreted as a function call or property access, respectively.

       Some examples of good semicolon usage:

           ;(x || y).doSomething()
           ;[a, b, c].forEach(doSomething)
           for (var i = 0; i < 10; i ++) {
             switch (state) {
               case "begin": start(); continue
               case "end": finish(); break
               default: throw new Error("unknown state")
             }
             end()
           }

       Note that starting lines with - and + also should be prefixed with a semicolon,  but  this
       is much less common.

Comma First

       If  there is a list of things separated by commas, and it wraps across multiple lines, put
       the comma at the start of the next line, directly below the token that  starts  the  list.
       Put the final token in the list on a line by itself. For example:

           var magicWords = [ "abracadabra"
                            , "gesundheit"
                            , "ventrilo"
                            ]
             , spells = { "fireball" : function () { setOnFire() }
                        , "water" : function () { putOut() }
                        }
             , a = 1
             , b = "abc"
             , etc
             , somethingElse

Whitespace

       Put  a  single  space  in  front  of ( for anything other than a function call. Also use a
       single space wherever it makes things more readable.

       Don´t leave trailing whitespace at the end of lines. Don´t indent empty lines.  Don´t  use
       more spaces than are helpful.

Functions

       Use named functions. They make stack traces a lot easier to read.

Callbacks, Sync/async Style

       Use  the  asynchronous/non-blocking  versions of things as much as possible. It might make
       more sense for npm to use the synchronous fs APIs, but this way, the fs and http and child
       process stuff all uses the same callback-passing methodology.

       The  callback  should  always  be the last argument in the list. Its first argument is the
       Error or null.

       Be very careful never to ever ever throw anything. It´s worse than useless. Just send  the
       error message back as the first argument to the callback.

Errors

       Always  create a new Error object with your message. Don´t just return a string message to
       the callback. Stack traces are handy.

Logging

       Logging is done using the npmlog https://github.com/isaacs/npmlog utility.

       Please clean up logs when they are no longer helpful.  In  particular,  logging  the  same
       object  over  and  over  again is not helpful. Logs should report what´s happening so that
       it´s easier to track down where a fault occurs.

       npm help  Use appropriate log levels. See npm-config and search for "loglevel".

Case, naming, etc.

       Use lowerCamelCase for multiword  identifiers  when  they  refer  to  objects,  functions,
       methods, members, or anything not specified in this section.

       Use UpperCamelCase for class names (things that you´d pass to "new").

       Use all-lower-hyphen-css-case for multiword filenames and config keys.

       Use named functions. They make stack traces easier to follow.

       Use CAPS_SNAKE_CASE for constants, things that should never change and are rarely used.

       Use  a  single  uppercase  letter  for function names where the function would normally be
       anonymous, but needs to call itself recursively. It makes it clear that it´s a "throwaway"
       function.

null, undefined, false, 0

       Boolean  variables  and functions should always be either true or false. Don´t set it to 0
       unless it´s supposed to be a number.

       When something is intentionally missing or removed, set it to null.

       Don´t set things to undefined. Reserve that value to mean "not yet set to anything."

       Boolean objects are verboten.

SEE ALSO

       •   npm help  developers

       •   npm help  faq

       •   npm help npm

                                           October 2013                       NPM-CODING-STYLE(7)