Build correct variables for testing translations

This makes sure we build the correct variables for testing
translations.

When translating, we could be specifying the variables in different
forms for each id:

- In the singular we could be using a `%{hash}` interpolation
- In the plural we could be using a `%d` interpolation

This changes the tests to accommodate for that: We now use the
variables used in the relevant translation id as the source for the
variables we mix in in specs.

lib/gitlab/i18n/po_linter.rb

@@ -170,13 +170,18 @@ module Gitlab
       end
 
       def translate_plural(entry)
-        used_variables = entry.plural_id.scan(VARIABLE_REGEX)
-        variables = fill_in_variables(used_variables)
+        used_plural_variables = entry.plural_id.scan(VARIABLE_REGEX)
+        plural_variables = fill_in_variables(used_plural_variables)
+
+        used_singular_variables = entry.msgid.scan(VARIABLE_REGEX)
+        singular_variables = fill_in_variables(used_singular_variables)
 
         numbers_covering_all_plurals.map do |number|
           translation = FastGettext::Translation.n_(entry.msgid, entry.plural_id, number)
+          index = index_for_pluralization(number)
+          variables = index == 0 ? singular_variables : plural_variables
 
-          translation % variables if used_variables.any?
+          translation % variables if variables.any?
         end
       end
 

spec/fixtures/valid.po

@@ -1128,3 +1128,8 @@ msgid "parent"
 msgid_plural "parents"
 msgstr[0] "padre"
 msgstr[1] "padres"
+
+msgid "CycleAnalytics|%{stageName}"
+msgid_plural "CycleAnalytics|%d stages selected"
+msgstr[0] "%{stageName}"
+msgstr[1] "%d stages selected"