add 'alias' option

[yoannisj]

For projects where your sass code is separated in different directories (bundles), it would be great to have an option to provide aliases. This option would map an arbitrary 'module/bundle' name to a sub-directories inside a project, in a similar way as what webpack does with its resolve.alias option.

Here is how it could work:

node file

var sass = require('node-sass'),
    importOnce = require('node-sass-import-once');

sass.render({
  file: scss_filename,
  importer: importOnce,
  importOnce: {
    bower: true,
    alias: {
      'foo': path.join(__dirname, './src/bundles/foo/stylesheets/scss'),
      'bar':  path.join(__dirname, './src/bundles/bar/stylesheets/scss')
    }
  }
});

sass file (can be in any directory, e.g. in ./src/bundles/baz/stylesheets/some/module/file)

@import "foo/module/filename"; // ./src/bundles/foo/module/(_)filename.s(c|a)ss
@import "bar/filename"; // ./src/bundles/bar/(_)filename.s(c|a)ss

Aliases would override bower/node modules in case of a name conflict.

[dougludlow]

I'd really like to see this as well.

[aharmo3]

+1