linklocal

linklocal

Create symlinks to local dependencies in your package.json.

linklocal is a development tool that the reduces overheads of breaking your application into small packages. It gives you more expressive power than simple files and folders, yet requires far less overhead than versioning and publishing packages to a local private registry.

Requires npm 2.0.0 and above in order for npm to recogise local paths as dependencies.

Installation

npm install -g linklocal

Usage

linklocal --help

  Usage: linklocal [options] <dir>

  Options:

    -h, --help             output usage information
    -f, --format [format]  output format
    -l, --link             Link local dependencies [default]
    -r, --recursive        Link recursively
    -q, --unique           Only unique lines of output
    -u, --unlink           Unlink local dependencies
    --absolute             Format output paths as absolute paths
    --files                Output only symlink targets (--format="%h") [default]
    --links                Output only symlinks (--format="%s")
    --list                 Only list local dependencies. Does not link.
    --long                 Output the symlink to hardlink mapping (--format="%s -> %h")
    --no-summary           Exclude summary i.e. "Listed 22 dependencies"
    -V, --version          output the version number

  Examples

    $ linklocal                 # link local deps in current dir
    $ linklocal link            # link local deps in current dir
    $ linklocal -r              # link local deps recursively
    $ linklocal unlink          # unlink only in current dir
    $ linklocal unlink -r       # unlink recursively

    $ linklocal list            # list all local deps, ignores link status
    $ linklocal list -r         # list all local deps recursively, ignoring link status

    $ linklocal -- mydir        # link local deps in mydir
    $ linklocal unlink -- mydir # unlink local deps in mydir

  Formats

    %s: relative path to symlink
    %S: absolute path to symlink
    %h: relative real path to symlink target
    %H: absolute real path to symlink target

    relative paths are relative to cwd

About

npm 2.0.0 supports specifying local dependencies in your package.json:

> npm install --save ../apple
> cat package.json
{
  "name": "bowl",
  "version": "1.0.0",
  "dependencies": {
    "apple": "file:../apple"
  }
}

npm install will copy (and npm install) the package into the target's node_module's hierarchy.

This is not an ideal workflow during development: any time you modify your local dependency, you must reinstall it in every location that depends on it. If you do not update all copies, you will have different versions of the same code, probably under the same version number.

Global npm link dependencies are also not ideal as packages clobber each other across projects.

By symlinking local dependencies while in development, changes can be instantly consumed by dependees, effects are limited to the current package and you can be more certain local dependees are using the latest changes.

linklocal symlinks both development and production dependencies.

Examples

Linking

linklocal creates symlinks to any local dependencies it finds in your package.json.

e.g. test/banana/package.json.

{
  "name": "banana",
  "version": "1.0.0",
  "private": true,
  "dependencies": {
    "apple": "file:../apple"
  }
}

Note file: dependencies are standard syntax in npm 2.x, just that npm will copy the dependency into place, rather than symlink it. That's what linklocal is for:

# from test/banana
# find local dependencies and symlink them
> linklocal
node_modules/apple -> ../apple

Linked 1 dependency
> # proof:
> ls -l node_modules
total 8
lrwxr-xr-x  1 timoxley  staff  11 20 Sep 01:39 apple -> ../../apple

Unlinking

You can unlink all local links using linklocal --unlink.

# from test/banana
> linklocal --unlink
node_modules/apple -> ../apple

Unlinked 1 dependency

> ls -l node_modules

>

Recursively Linking local dependencies in local dependencies

If your local dependencies themselves might have local dependencies, you can use linklocal -r to recursively link all local dependencies:

bowl depends on banana banana depends on apple

With Recursion

apple gets linked into banana

node_modules/apple -> ../apple
node_modules/banana -> ../banana
../banana/node_modules/apple -> ../apple
node_modules/@nuts/almond -> ../almond

Linked 4 dependencies

Without Recursion

apple does not get linked into banana

# from test/bowl
> linklocal
node_modules/apple -> ../apple
node_modules/banana -> ../banana
node_modules/@nuts/almond -> ../almond

Linked 3 dependencies

Recommendations

linklocal does not install dependencies of linked dependencies. To have dependencies installed, use timoxley/bulk or xargs in a script like:

{
  "name": "my-app",
  "scripts": {
    "dev": "linklocal link -r && linklocal list -r | bulk -c 'npm install --production'",
    "prepublish": "if [[ $NODE_ENV != 'production' ]]; then npm run dev; fi"
  }
}

Caveats

• linklocal does not install dependencies of linked dependencies, as such you typically end up installing dependencies of linked dependencies twice: once during npm install, then again after linklocal

See Also

• aperture
• district
• symlink

License

MIT