sass.rb

## Imagine the following files:

# foo.css.scss

@import bar

foo {
  @include bar
}

# bar.css.scss

mixin bar {
  bar: baz
}

# Today, when I give it to SASS template handler, the template handler is going
# to return a string that will result in the following compiled method:

def compiled_method
  "foo {\n  bar: baz }"
end

# This method already included the mixin. This means that, to know if we need to
# recompile the file, we need to track everything that was already imported.

# My approach relies on pre-compiliation. The compiled template sass would
# generate would be like this:

def compiled_template
  Sass.importer.find("omg")
  "\nfoo{" << Sass::Mixins.handle(:bar, :ident => 2) << "}"
end

# Look that the mixin was not included and it will only be once we call render.
# In production, render will be called just on the first request, but in every
# request in development. But since it is simply doing string concatenation,
# it will still be really fast!
#
# The huge benefit is that we don't need to track dependencies, no trees!