Can't access Middleman data files, helpers

[erosdome]

Upon loading, I get:

undefined local variable or method `data' for #<#<Class:0x007f9913a97528>:0x007f99157d60f8>

Most of my scripts are .js.erb since I pull a lot of strings from Middleman data .yml files, so I have a lot of code like this:

var aString = "<%= data[:strings][:a_string] %>";

which works fine, except when running Jasmine-tests, as if Jasmine would not load Middleman data files. Is there a configuration setting where I can tell Jasmine to do so?

UPDATE:

It seems I also can't use Middleman helpers. I receive the same error when trying to use a Middleman helper defined in Middleman's config.rb file.