Warn when a locale's stringsdict entry is only partially translated

A `.po` entry with some — but not all — plural forms filled in passes
the form-count check, so the reverse conversion mapped what it had,
omitted the blank categories, and back-filled `other` from a sibling
form — silently. iOS then shows the wrong plural for the untranslated
counts (a Russian entry missing `many` renders the `few` text for 5, 6,
7, …), with nothing in the `missing` report to flag it.

`warn_partial_translation` now emits a `UI.important` naming the locale,
context, and which CLDR forms are untranslated. Partial entries stay out
of the `missing` list (which means "no translation at all"), so the two
cases aren't conflated. Output and the returned list are unchanged — the
tool can't supply the absent translation, only make the gap visible so a
translator finishes it.

Author: jkmassel

CHANGELOG.md

@@ -11,7 +11,7 @@ _None_
 ### New Features
 
 - Added `find_or_create_pull_request` action and `GithubHelper#find_pull_request`: returns the URL of the open Pull Request for a head branch, creating one only if none exists yet. Useful for "rolling" automations (e.g. a daily translations or dependency-update job) that force-push the same head branch on every run. [#733]
-- Added `ios_generate_pot_from_stringsdict` and `ios_generate_stringsdict_from_po` actions to round-trip iOS `.stringsdict` plural files through a gettext `.po`/`.pot`-based translation system (e.g. GlotPress). The forward action turns an English `.stringsdict` into a `.pot` template (one `msgid`/`msgid_plural` per plural variable); the reverse rebuilds a per-locale `.stringsdict` from a translated `.po`, mapping gettext's indexed plural forms back to CLDR plural categories (`one`/`few`/`many`/…) via the new `Ios::PluralRules` table and using the English `.stringsdict` as a structural template. The forward action round-trips only the `one`/`other` forms; other CLDR categories in the source (e.g. a `zero` literal override) are dropped with a warning. [#739]
+- Added `ios_generate_pot_from_stringsdict` and `ios_generate_stringsdict_from_po` actions to round-trip iOS `.stringsdict` plural files through a gettext `.po`/`.pot`-based translation system (e.g. GlotPress). The forward action turns an English `.stringsdict` into a `.pot` template (one `msgid`/`msgid_plural` per plural variable); the reverse rebuilds a per-locale `.stringsdict` from a translated `.po`, mapping gettext's indexed plural forms back to CLDR plural categories (`one`/`few`/`many`/…) via the new `Ios::PluralRules` table and using the English `.stringsdict` as a structural template. The forward action round-trips only the `one`/`other` forms; other CLDR categories in the source (e.g. a `zero` literal override) are dropped with a warning. The reverse action likewise warns when a locale's plural entry is only partially translated. [#739]
 
 ### Bug Fixes
 

lib/fastlane/plugin/wpmreleasetoolkit/helper/ios/ios_stringsdict_helper.rb

@@ -164,6 +164,7 @@ def self.generate_stringsdict_from_po(po_path:, template_path:, locale:, output_
                 localized[var_name] = english_variable(var_dict)
               else
                 validate_form_count!(forms: forms, categories: categories, context: context, locale: locale)
+                warn_partial_translation(context: context, locale: locale, categories: categories, forms: forms)
                 localized[var_name] = localized_variable(source_var: var_dict, categories: categories, forms: forms)
               end
             end
@@ -260,6 +261,22 @@ def self.validate_form_count!(forms:, categories:, context:, locale:)
                 'configuration for this locale does not match the expected CLDR categories.'
         end
 
+        # A translated entry that has some — but not all — of its plural forms
+        # filled still passes the count check. The blank categories are omitted
+        # from the `.stringsdict`, so iOS falls back to another form for those
+        # counts, silently showing the wrong plural. Surface it the way the
+        # forward path surfaces dropped categories, rather than shipping it.
+        def self.warn_partial_translation(context:, locale:, categories:, forms:)
+          blank = categories.each_index.select { |i| forms[i].nil? || forms[i].to_s.empty? }.map { |i| categories[i] }
+          return if blank.empty?
+
+          UI.important(
+            "Translation for '#{context}' (locale '#{locale}') is incomplete — the " \
+            "#{blank.join(', ')} plural form(s) are untranslated; those counts will fall " \
+            'back to another form. Finish the translation so every count shows the right plural.'
+          )
+        end
+
         # Build a localized variable dictionary by mapping indexed forms to CLDR
         # categories and copying structure from the source variable.
         def self.localized_variable(source_var:, categories:, forms:)

spec/ios_stringsdict_helper_spec.rb

@@ -257,6 +257,23 @@ def convert_po_to_stringsdict(po_content, template:, locale:)
       expect(data['%d items']['count']).to include('one' => '%d item', 'other' => '%d items')
     end
 
+    it 'warns when a locale entry is only partially translated' do
+      expect(FastlaneCore::UI).to receive(:important) do |message|
+        expect(message).to include('many')
+        expect(message).to match(/incomplete|untranslated/i)
+      end
+      # `ru` needs one/few/many; the translator left `many` blank.
+      data, missing = convert_po_to_stringsdict(
+        simple_po(forms: ['ru-one', 'ru-few', ''], nplurals: 3),
+        template: simple, locale: 'ru'
+      )
+      # Not reported as fully-missing — it does have *some* translation…
+      expect(missing).to be_empty
+      # …but the untranslated `many` is absent (falls back), not silently wrong-but-present.
+      expect(data['%d items']['count']).not_to have_key('many')
+      expect(data['%d items']['count']).to include('one' => 'ru-one', 'few' => 'ru-few', 'other' => 'ru-few')
+    end
+
     it 'maps Hebrew to one/other — GlotPress is 2-form, so the CLDR dual is not represented' do
       data, missing = convert_po_to_stringsdict(
         simple_po(forms: ['פריט אחד', '%d פריטים'], plural: 'n != 1'),