lomod

Local Module Require

Usage no npm install needed!

<script type="module">
  import lomod from 'https://cdn.skypack.dev/lomod';
</script>

README

lomod

Loading modules from not only 'node_modules' but also 'lib' folders, which usually contains project's local modules.

Install

npm install lomod

Usage

project/
  + common/
  |  + local_modules/
  |     + common-util.js
  + app/
     + local_modules/
     |  + app-util.js
     + submod/
     |  + local_modules/
     |  |  + libdir/
     |  |  |  + dir-util.js
     |  |  + sub-util.js
     |  + test.js
     + package.json

app/submod/test.js

var lomod = require('lomod');

// use as a replacement of original require
var fs = lomod('fs');

var sutil = lomod('sub-util');
var dutil = lomod('libdir/dir-util');
var autil = lomod('app-util');
var cutil = lomod('common-util');

app/package.json

{
  "name": "proj-app",
  "version": "1.0.0",
  "localDependencies": [
    "../common"
  ]
}

Looking-up Modules

Any module identifier passed to lomod() will be tried on original require first.

If this failed, and the module identifier does not begin with '/', '../', or './', then lomod starts at the current directory, adds /LOCAL_MODULE_DIRNAME, and attempts to load the module from that location. (LOCAL_MODULE_DIRNAME could be 'local_modules' or 'lib' for default)

If it is not found there, then it moves to the parent directory, and so on, until the root of the tree is reached, or a package.json with property localDependencies was found (check the next chapter).

For example, if the file at '/home/ry/projects/foo.js' called lomod('bar.js'), then lomod would look in the following locations, in this order:

try to require('bar.js')
/home/ry/projects/local_modules/bar.js
/home/ry/local_modules/bar.js
/home/local_modules/bar.js
/local_modules/bar.js
/home/ry/projects/lib/bar.js
/home/ry/lib/bar.js
/home/lib/bar.js
/lib/bar.js

This is almost same with the original require, just consider it as you got two extra module directories beside 'node_modules'.

Local Module Dirs

Lomod find local modules in directories named 'local_modules' or 'lib' by default. You can customize these names if they didn't fit your need:

var lomod = require('lomod').in('lib', 'mylib')

Then lomod will find local modules in directories named 'lib' or 'mylib', the default directories 'local_modules' will be ignored.

You can also use empty string as dirname:

var lomod = require('lomod').in('')
var tools = lomod('local_modules/tools')

is equals to:

var lomod = require('lomod').in('local_modules')
var tools = lomod('tools')

Local Dependencies

A "localDependencies" property with string array value in package.json stop the recusive moving to parent directory. Instead of it, lomod start looking up from each path in this array.

For example, if the file at '/home/ry/projects/foo.js' called lomod('bar.js'), and the file at '/home/ry/package.json' contains localDependencies assigned ['/share', '/usr/share'], then lomod would look in the following locations, in this order:

try to require('bar.js')
/home/ry/projects/local_modules/bar.js
/home/ry/local_modules/bar.js    (go to localDependencies)
/share/local_modules/bar.js
/local_modules/bar.js
/usr/share/local_modules/bar.js
/usr/local_modules/bar.js
/local_modules/bar.js            (has been scaned, ignore)
/home/ry/projects/lib/bar.js     (continue with local module dir "lib")
....

Lomod ignored '/home/lib/bar.js' in this example. You can simply prevent it by append '..' to the localDependencies array.

Ignore Original Require

Lomod will try to load module by original require first. You can ignore this by use lomod.requireLocal and lomod.resolveLocal

project/
  + local_modules/
  |  + util.js
  + main.js

main.js

var sys_util = require('util');
var my_util  = lomod.requireLocal('util');
var my_util2 = require(lomod.resolveLocal('util'));

You can also specify a starting directory. Original require will also be ignored in this situation:

var util = lomod('util', '/opt/my_lib/');
// will be found in /opt/my_lib/local_modules/util

Support Other File Formats

Any format supported by original require will be inherited to lomod.

project/
  + node_modules/
  |  + res.yaml
  + local_modules/
  |  + lores.yaml
  + test.js

test.js

require('require-yaml');

var res = require('res');
var lomod = require('lomod'),
    lores = lomod('lores');

some format modules by olalonde

These modules support extra formats by adding handlers to require.extensions which is a deprecated feature in node's module system. Since the module system is locked, this feature will probably never go away but may have subtle bugs. Use on your own risk.