Ubuntu Manpage: npm-developers

NAME

       npm-developers - Developer Guide

DESCRIPTION

       So, you've decided to use npm to develop (and maybe publish/deploy) your project.

       Fantastic!

       There  are a few things that you need to do above the simple steps that your users will do
       to install your program.

About These Documents

       These are man pages.  If you install npm, you should be able to then do man  npm-thing  to
       get  the  documentation  on  a  particular  topic,  or  npm  help  thing  to  see the same
       information.

What is a package

       A package is:

       · a) a folder containing a program described by a package.json file

       · b) a gzipped tarball containing (a)

       · c) a url that resolves to (b)

       · d) a <name>@<version> that is published on the registry with (c)

       · e) a <name>@<tag> that points to (d)

       · f) a <name> that has a "latest" tag satisfying (e)

       · g) a git url that, when cloned, results in (a).

       Even if you never publish your package, you can still get a lot of benefits of  using  npm
       if  you  just want to write a node program (a), and perhaps if you also want to be able to
       easily install it elsewhere after packing it up into a tarball (b).

       Git urls can be of the form:

         git://github.com/user/project.git#commit-ish
         git+ssh://user@hostname:project.git#commit-ish
         git+http://user@hostname/project/blah.git#commit-ish
         git+https://user@hostname/project/blah.git#commit-ish

       The commit-ish can be any tag, sha, or branch which can be supplied as an argument to  git
       checkout.  The default is master.

The package.json File

You need to have a package.json file in the root of your project to do much of anything
with npm. That is basically the whole interface.

See npm help 5 package.json for details about what goes in that file. At the very least,
you need:

· name: This should be a string that identifies your project. Please do not use the name
to specify that it runs on node, or is in JavaScript. You can use the "engines" field
to explicitly state the versions of node (or whatever else) that your program requires,
and it's pretty well assumed that it's JavaScript. It does not necessarily need to
match your github repository name. So, node-foo and bar-js are bad names. foo or bar
are better.

· version: A semver-compatible version.

· engines: Specify the versions of node (or whatever else) that your program runs on. The
node API changes a lot, and there may be bugs or new functionality that you depend on.
Be explicit.

· author: Take some credit.

· scripts: If you have a special compilation or installation script, then you should put
it in the scripts object. You should definitely have at least a basic smoke-test
command as the "scripts.test" field. See npm help 7 scripts.

· main: If you have a single module that serves as the entry point to your program (like
what the "foo" package gives you at require("foo")), then you need to specify that in
the "main" field.

· directories: This is an object mapping names to folders. The best ones to include are
"lib" and "doc", but if you use "man" to specify a folder full of man pages, they'll get
installed just like these ones.

You can use npm init in the root of your package in order to get you started with a pretty
basic package.json file. See npm help npm-init for more info.

Keeping files out of your package
Use a .npmignore file to keep stuff out of your package. If there's no .npmignore file,
but there is a .gitignore file, then npm will ignore the stuff matched by the .gitignore
file. If you want to include something that is excluded by your .gitignore file, you can
create an empty .npmignore file to override it. Like git, npm looks for .npmignore and
.gitignore files in all subdirectories of your package, not only the root directory.

.npmignore files follow the same pattern rules
https://git-scm.com/book/en/v2/Git-Basics-Recording-Changes-to-the-Repository#Ignoring-Files
as .gitignore files:

· Blank lines or lines starting with # are ignored.

· Standard glob patterns work.

· You can end patterns with a forward slash / to specify a directory.

· You can negate a pattern by starting it with an exclamation point !.

By default, the following paths and files are ignored, so there's no need to add them to
.npmignore explicitly:

· .*.swp

· ._*

· .DS_Store

· .git

· .hg

· .npmrc

· .lock-wscript

· .svn

· .wafpickle-*

· config.gypi

· CVS

· npm-debug.log

Additionally, everything in node_modules is ignored, except for bundled dependencies. npm
automatically handles this for you, so don't bother adding node_modules to .npmignore.

The following paths and files are never ignored, so adding them to .npmignore is
pointless:

· package.json

· README (and its variants)

· CHANGELOG (and its variants)

· LICENSE / LICENCE

If, given the structure of your project, you find .npmignore to be a maintenance headache,
you might instead try populating the files property of package.json, which is an array of
file or directory names that should be included in your package. Sometimes a whitelist is
easier to manage than a blacklist.

Testing whether your .npmignore or files config works
If you want to double check that your package will include only the files you intend it to
when published, you can run the npm pack command locally which will generate a tarball in
the working directory, the same way it does for publishing.

Link Packages

       npm  link  is  designed  to install a development package and see the changes in real time
       without having to keep re-installing it.  (You do need to either re-link or npm rebuild -g
       to update compiled packages, of course.)

       More info at npm help npm-link.

Before Publishing: Make Sure Your Package Installs and Works

       This is important.

       If  you  can not install it locally, you'll have problems trying to publish it.  Or, worse
       yet, you'll be able to publish it, but you'll be publishing a broken or pointless package.
       So don't do that.

       In the root of your package, do this:

         npm install . -g

       That'll  show  you  that it's working.  If you'd rather just create a symlink package that
       points to your working directory, then do this:

         npm link

       Use npm ls -g to see if it's there.

       To test a local install, go into some other folder, and then do:

         cd ../some-other-folder
         npm install ../my-package

       to install it locally into the node_modules folder in that other place.

       Then go into the node-repl, and try using require("my-thing") to bring  in  your  module's
       main module.

Create a User Account

       Create a user with the adduser command.  It works like this:

         npm adduser

       and then follow the prompts.

       This is documented better in npm help adduser.

Publish your package

       This part's easy.  In the root of your folder, do this:

         npm publish

       You  can  give  publish  a  url  to  a tarball, or a filename of a tarball, or a path to a
       folder.

       Note that pretty much everything in that folder will be exposed by default.   So,  if  you
       have  secret  stuff  in  there,  use a .npmignore file to list out the globs to ignore, or
       publish from a fresh checkout.

Brag about it

       Send emails, write blogs, blab in IRC.

       Tell the world how easy it is to install your program!