ruby - Test an ERB Template -

i've written template stuff json object, example:

{   "list": [     <% ['a', 'b', 'c', 'd'].each |letter| %>      <%= puts "{ \"letter\": \"" + letter + "\" }," %>     <% end %>    ] } 

how can write unit test check if json output valid? i'm new ruby don't know tools use this. also, there better way make list of json objects in erb template?

i don't have access to, or knowledge of thing that's processing template i'm not positive ruby libraries can consume.

note: rails not involved. vanilla ruby.

if trying return object or list json, can call render json: object controller. can test same way can test other controller: http://guides.rubyonrails.org/testing.html#functional-tests-for-your-controllers

if absolutely need in erb whatever reason, can call .to_json method on object between erb tags: <%= object.to_json %>.

the .to_json method return valid json.