How to automatically copy files from package to local directory via postinstall npm script?

Question

I want to automatically copy certain files from an npm package to user's local directory after running

npm install my-package

I can get them installed by declaring "files" inside package.json. The problem is --- the files are not put in the local directory. So I need to run postinstall script.

But now I don't know where the package is installed (maybe higher up the directory tree), so how can I reliably access the files and copy them to the local directory via the script?

(By local directory I mean --- from where I run npm install my-package as user consuming the package.)

UPDATE. It seems the postinstall script runs as npm owned process with home directory being node_modules/my-package, so I still don't know how to access user's home directory other than with naive ../../.

An old question, I know but I'm facing a similar issue. Did you ever find a good solution for this? — danielv, Dec 20 '16 at 20:06
Thanks. I hoped that you found a more elegant solution for finding the base install directory other than `../../`. — danielv, Dec 21 '16 at 08:14
@danielv Please let me know, should you ever come across a better solution. — Dmitri Zaitsev, Dec 24 '16 at 01:54
@danielv Eventually, when even `npm` and `yarn` cannot agree on where to install, I have found this naive solution the most convenient and reliable one. — Dmitri Zaitsev, Apr 11 '17 at 08:21
And if you, in the path of the current file, try to determine which is the last "node_modules" directory in the left? the previous directory is the local dir? — Lucabro, Jul 11 '18 at 20:19

score 17 · Answer 1 · answered Jul 11 '18 at 09:59

Since npm 3.4 you can use the $INIT_CWD envar: https://blog.npmjs.org/post/164504728630/v540-2017-08-22

When running lifecycle scripts, INIT_CWD will now contain the original working directory that npm was executed from.

To fix you issue add to your postinstall script in package.json the following:

  "scripts": {
    "postinstall": "cp fileYouWantToCopy $INIT_CWD",
  },

David Bradshaw · Answer 2 · 2021-01-08T14:16:35.070

After a lot of searching I found this works cross platform

"scripts":
  "postinstall": "node ./post-install.js",


// post-install.js

/**
 * Script to run after npm install
 *
 * Copy selected files to user's directory
 */

'use strict'

var gentlyCopy = require('gently-copy')

var filesToCopy = ['.my-env-file', 'demo']

// User's local directory
var userPath = process.env.INIT_CWD

// Moving files to user's local directory
gentlyCopy(filesToCopy, userPath)

score 3 · Answer 3 · answered Jan 14 '16 at 06:43

3

var cwd = require('path').resolve();

Note: If the arguments to resolve have zero-length strings then the current working directory will be used instead of them.

from https://nodejs.org/api/path.html

answered Jan 14 '16 at 06:43

hexagoncode

141
2
6

I am still confused which is `cwd` inside the `postinstall` script --- the local directory or where the installed files are sitting? – Dmitri Zaitsev Jan 14 '16 at 08:05
`cwd` is always where a program was executed from. If you need a path to current js file from a file itself there are `__filename` and `__dirname` variables available in every file. – hexagoncode Jan 15 '16 at 04:29
I need path to the local directory, see last line in my question to define what I mean. – Dmitri Zaitsev Jan 15 '16 at 08:07
Unfortunately this method does not solve the problem. As the `node` scripts are executed from their package directory under `node_modules`, their `cwd` will never point to the local directory from where the user ran `npm install`. – Dmitri Zaitsev Apr 11 '17 at 09:12

score 2 · Answer 4 · edited Feb 26 '19 at 00:10

2

I would use shellscript/bash

-package.json

"scripts":
  "postinstall": "./postinstall.sh",

-postinstall.sh

#!/bin/bash

# go to YOUR_NEEDED_DIRECTORY .e.g "dist" or $INIT_CWD/dist
cd YOUR_NEEDED_DIRECTORY

# copy each file/dir to user dir(~/)
for node in `ls`
do
  cp -R $node ~/$node
done

Don't forget to!

chmod +x postinstall.sh

edited Feb 26 '19 at 00:10

Graham P Heath

7,009
3
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answered Apr 06 '17 at 23:04

nothing-special-here

11,230
13
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1

It is not clear how this can help, I still need to know how to refer to the local directory in this code, so the same problem remains. – Dmitri Zaitsev Apr 11 '17 at 05:57
Because your script is running as part of a life cycle event, $INIT_CWD is available in this script. – Graham P Heath Feb 26 '19 at 00:09

How to automatically copy files from package to local directory via postinstall npm script?

4 Answers4