A furry little helper for dealing with optional NPM dependencies
Squirrel is a helpful node module that assists you requiring your
dependencies for plugins of your application (version controlled via a
pluginDependencies in your
Because personally, I really don't like the sitting waiting for a node package to install a whole swag of dependencies because it requires them for some functionality that I don't intend to use. I believe using squirrel will enable certain types of packages to have a leaner core with properly managed and installable optional dependencies.
If you are using
optionalDependencies in your application, you might
pluginDependencies instead and then "squirreling"
them rather than requiring them.
NOTE: Squirreling is an asynchronous operation:
var squirrel = require'squirrel';squirrel'coffee-script'// do something magical with coffeescript...;
If you need multiple modules, then squirrel is happy to play in a way similar to the way AMD module loaders do:
squirrel'coffee-script' 'jade'// do something with both coffeescript and jade...;
Squirrel has been built to support a number of "Allow Install" modes, which
is controlled in an
allowInstall option that the squirrel function accepts
in the 2nd argument, e.g.:
// install jade, and don't trigger a prompt if not already availablesquirrel'jade' allowInstall: true;
The default setting for the
allowInstall option is set to
means that when a module using
squirrel attempts to squirrel one or more
modules, the user will be prompted if they want to allow those modules to
install. If they don't permit installation then the squirrel operation
will fail and an error will be returned in the callback.
Other valid settings for the
allowInstall option are
dependencies without prompting) or
false (always reject module requests).
A squirrel's got to have options. The demands on the modern squirrel mean that having options is important, and this squirrel is not different. Here are the options that squirrel supports in a 2nd (optional) argument.
allowInstall- as outlined above.
promptMessage- 'Package "<%= target %>" is required. Permit install? '
cwd- the path to squirrel in
installCommand- '<%= opts.installer %> install <%= target %>@<%= version %>'
uninstallCommand- '<%= opts.installer %> rm <%= target %>'
The default options can be modified through modifying them in
You could argue that given squirrel's mission is to reduce the overall number of package dependencies, it should be ultralight in it's own packaging. While that's a valid point, I think a balance is required and using existing well-tested libraries is important.
Request the installation of the modules specified in the
Remove the specified targets. Used in squirrel tests and I guess in some cases might be useful in production code also.
This module constains the installer helper functions used within squirrel. Each of the functions outlined below is designed to be called initially with an options object, which then provides you the function signature outlined in the docs.
var installer = require'squirrel/installer';
Use npm to install the required target.
This is the first step called in the pull-stream when squirrel is asked for particular modules. It will determine what action is required based on what has been asked for, depending on a number of factors:
Execute the required installer operation
Copyright (c) 2014 Damon Oehlman email@example.com
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