1DEVELOPERS(7) DEVELOPERS(7)
2
6 developers - Developer Guide
7 Description
9 So, you've decided to use npm to develop (and maybe publish/deploy)
10 your project.
11 Fantastic!
13 There are a few things that you need to do above the simple steps that
15 your users will do to install your program.
16 About These Documents
18 These are man pages. If you install npm, you should be able to then do
19 man npm-thing to get the documentation on a particular topic, or npm
20 help thing to see the same information.
21 What is a package
23 A package is:
24 • a) a folder containing a program described by a package.json file
26 • b) a gzipped tarball containing (a)
28 • c) a url that resolves to (b)
30 • d) a <name>@<version> that is published on the registry with (c)
32 • e) a <name>@<tag> that points to (d)
34 • f) a <name> that has a "latest" tag satisfying (e)
36 • g) a git url that, when cloned, results in (a).
38 Even if you never publish your package, you can still get a lot of ben‐
41 efits of using npm if you just want to write a node program (a), and
42 perhaps if you also want to be able to easily install it elsewhere af‐
43 ter packing it up into a tarball (b).
44 Git urls can be of the form:
46 git://github.com/user/project.git#commit-ish
48 git+ssh://user@hostname:project.git#commit-ish
49 git+http://user@hostname/project/blah.git#commit-ish
50 git+https://user@hostname/project/blah.git#commit-ish
51 The commit-ish can be any tag, sha, or branch which can be supplied as
53 an argument to git checkout. The default is master.
54 The package.json File
56 You need to have a package.json file in the root of your project to do
57 much of anything with npm. That is basically the whole interface.
58 See npm help package.json for details about what goes in that file. At
60 the very least, you need:
61 • name: This should be a string that identifies your project. Please
63 do not use the name to specify that it runs on node, or is in Java‐
64 Script. You can use the "engines" field to explicitly state the ver‐
65 sions of node (or whatever else) that your program requires, and it's
66 pretty well assumed that it's JavaScript. It does not necessarily
67 need to match your github repository name. So, node-foo and bar-js
68 are bad names. foo or bar are better.
69 • version: A semver-compatible version.
71 • engines: Specify the versions of node (or whatever else) that your
73 program runs on. The node API changes a lot, and there may be bugs
74 or new functionality that you depend on. Be explicit.
75 • author: Take some credit.
77 • scripts: If you have a special compilation or installation script,
79 then you should put it in the scripts object. You should definitely
80 have at least a basic smoke-test command as the "scripts.test" field.
81 See npm help scripts.
82 • main: If you have a single module that serves as the entry point to
84 your program (like what the "foo" package gives you at re‐
85 quire("foo")), then you need to specify that in the "main" field.
86 • directories: This is an object mapping names to folders. The best
88 ones to include are "lib" and "doc", but if you use "man" to specify
89 a folder full of man pages, they'll get installed just like these
90 ones.
91 You can use npm init in the root of your package in order to get you
94 started with a pretty basic package.json file. See npm help init for
95 more info.
96 Keeping files out of your package
98 Use a .npmignore file to keep stuff out of your package. If there's no
99 .npmignore file, but there is a .gitignore file, then npm will ignore
100 the stuff matched by the .gitignore file. If you want to include some‐
101 thing that is excluded by your .gitignore file, you can create an empty
102 .npmignore file to override it. Like git, npm looks for .npmignore and
103 .gitignore files in all subdirectories of your package, not only the
104 root directory.
105 .npmignore files follow the same pattern rules
107 https://git-scm.com/book/en/v2/Git-Basics-Record‐
108 ing-Changes-to-the-Repository#Ignoring-Files as .gitignore files:
109 • Blank lines or lines starting with # are ignored.
111 • Standard glob patterns work.
113 • You can end patterns with a forward slash / to specify a directory.
115 • You can negate a pattern by starting it with an exclamation point !.
117 By default, the following paths and files are ignored, so there's no
120 need to add them to .npmignore explicitly:
121 • .*.swp
123 • ._*
125 • .DS_Store
127 • .git
129 • .hg
131 • .npmrc
133 • .lock-wscript
135 • .svn
137 • .wafpickle-*
139 • config.gypi
141 • CVS
143 • npm-debug.log
145 Additionally, everything in node_modules is ignored, except for bundled
148 dependencies. npm automatically handles this for you, so don't bother
149 adding node_modules to .npmignore.
150 The following paths and files are never ignored, so adding them to
152 .npmignore is pointless:
153 • package.json
155 • README (and its variants)
157 • CHANGELOG (and its variants)
159 • LICENSE / LICENCE
161 If, given the structure of your project, you find .npmignore to be a
164 maintenance headache, you might instead try populating the files prop‐
165 erty of package.json, which is an array of file or directory names that
166 should be included in your package. Sometimes a whitelist is easier to
167 manage than a blacklist.
168 Testing whether your .npmignore or files config works
170 If you want to double check that your package will include only the
171 files you intend it to when published, you can run the npm pack command
172 locally which will generate a tarball in the working directory, the
173 same way it does for publishing.
174 Link Packages
176 npm link is designed to install a development package and see the
177 changes in real time without having to keep re-installing it. (You do
178 need to either re-link or npm rebuild -g to update compiled packages,
179 of course.)
180 More info at npm help link.
182 Before Publishing: Make Sure Your Package Installs and Works
184 This is important.
185 If you can not install it locally, you'll have problems trying to pub‐
187 lish it. Or, worse yet, you'll be able to publish it, but you'll be
188 publishing a broken or pointless package. So don't do that.
189 In the root of your package, do this:
191 npm install . -g
193 That'll show you that it's working. If you'd rather just create a sym‐
195 link package that points to your working directory, then do this:
196 npm link
198 Use npm ls -g to see if it's there.
200 To test a local install, go into some other folder, and then do:
202 cd ../some-other-folder
204 npm install ../my-package
205 to install it locally into the node_modules folder in that other place.
207 Then go into the node-repl, and try using require("my-thing") to bring
209 in your module's main module.
210 Create a User Account
212 Create a user with the adduser command. It works like this:
213 npm adduser
215 and then follow the prompts.
217 This is documented better in npm help adduser.
219 Publish your package
221 This part's easy. In the root of your folder, do this:
222 npm publish
224 You can give publish a url to a tarball, or a filename of a tarball, or
226 a path to a folder.
227 Note that pretty much everything in that folder will be exposed by de‐
229 fault. So, if you have secret stuff in there, use a .npmignore file to
230 list out the globs to ignore, or publish from a fresh checkout.
231 Brag about it
233 Send emails, write blogs, blab in IRC.
234 Tell the world how easy it is to install your program!
236 See also
238 • npm help npm
239 • npm help init
241 • npm help package.json
243 • npm help scripts
245 • npm help publish
247 • npm help adduser
249 • npm help registry
251 April 2021 DEVELOPERS(7)