API User details: format tweaks

- _show_ to return single user only
- remove nesting for languages

app/views/api/users/_user.json.jbuilder

@@ -54,11 +54,7 @@ json.user do
       end
     end
 
-    if user.languages
-      json.languages do
-        json.array! user.languages.split(",")
-      end
-    end
+    json.languages user.languages if user.languages?
 
     json.messages do
       json.received do

app/views/api/users/show.json.jbuilder

@@ -1,3 +1 @@
-json.users([@user]) do |user|
-  json.partial! user
-end
+json.partial! @user

test/controllers/api/users_controller_test.rb

@@ -81,6 +81,15 @@ module Api
       # check that a non-existent user is not returned
       get api_user_path(:id => 0)
       assert_response :not_found
+
+      # check that a visible user is returned properly in json
+      get api_user_path(:id => user.id, :format => "json")
+      assert_response :success
+      assert_equal "application/json", response.media_type
+
+      js = ActiveSupport::JSON.decode(@response.body)
+      assert_not_nil js
+      assert_equal user.id, js["user"]["id"]
     end
 
     def test_details