Node modules cache

Speeds up npm install / npm ci commands. Especially if you have multi-core CPU.

Known issue on Windows

You must have tar, supporting xpJSf options, in your OS.
So everything is ok on Linux. But for Windows you must use tar from cygwin or smth like.
I could use npm tar module, but it supports max 99 symbols in file name.
If tar module will be fixed, I will use it.

Installation

npm install -g @dzenly/nmc

Usage

$3

Runs npm with the specified arguments (saving node_modules in cache) or unzips archieve from cache.

$3

Cleans the whole nmc cache.

$3

Returns size of current cache.

$3

* nmc ci
* nmc ci --production
* nmc install

How it works

It calculates sha256 hash from:
* os.arch()
* os.platform()
* os.release()
* os.type()
* process.versions
* npm --version
* npm arguments passed in the command line
* package.json
* package-lock.json (if exists)
* npm-shrinkwrap.json (if exists)

If hash is found in cache - just unzips it from cache.

If hash is not found - runs npm with specified parameters and then saves node_modules to
the inner directory (cache) as .txz.

Warning about postinstall.

nmc checks stdout to detect if there was postinstall run for the main module (not for dependencies),
and if yes - it will run npm run postistall after unzipping of cached archive.

So if your dependencies do something outside its node_modules, nmc, probably, is not for you.

About uninstall

Please, use only npm arguments destined to installation. For other arguments the behaviour is undefined.

nmc does not support uninstall. So you can use npm install -S some-module and then run nmc install
to cache you new node_modules.

About nmc install some-new-module

No, no, no. Use only commands for the whole node_modules installation
for your package.json, package-lock.json and npm-shrinkwrap.json.

Use cases

* CI builds speed up.
* Fast branch switching for developers.

Environment variables

* NPM_ORIG - path to npm binary, it allows to create such a script at your ~/bin/npm.

``
#!/usr/bin/env bash

if [ -z "$NPM_ORIG" ]; then
export NPM_ORIG=$(dirname $(which nmc))/npm
fi

if [[ -n "$NPM_USE_NMC" ]]; then
if [[ "$1" == "install" || "$1" == "i" || "$1" == "ci" ]];then
echo Install by NMC $NPM_ORIG "$@"
nmc "$@"
exit
fi
fi

echo Install by NPM $NPM_ORIG "$@"

$NPM_ORIG "$@"
`

And add it to path: export PATH=~/bin:$PATH`

So nmc will be used instead of npm if NPM_USE_NMC will be defined.