From be80973e447bb8bd369acc7cfc9f8d4393c5ffdd Mon Sep 17 00:00:00 2001
From: voodoorai2000 <voodoorai2000@gmail.com>
Date: Thu, 27 Sep 2018 18:11:28 +0200
Subject: [PATCH] Avoid InvalidPluralizationData exception when missing
 translations

We work with many languages using Crowdin[1]

Sometimes translators forget to fill in all the necessary plural forms of a translation (zero, one, other) and in those cases we were seing the exception InvalidPluralizationData being raised

There are a number of approches to fix this... from being more strict when approving translations, to automatically extrapolating what those plural forms should be

For now, we've gone for a simple approach to display the actual count(0,1,2,3,4, etc) instead of the whole translation

So, if the plural form of "1 comment" is missing, just a "1" will be displayed and no exceptions raised

Note: The first two specs, test what is really Rails' functionalities. However as we are monkey patching the pluralize method, I thought it was appropriate to doble check it

[1]https://crowdin.com/project/consul
---
 config/initializers/i18n_pluralize.rb | 19 +++++++++++
 spec/i18n_spec.rb                     | 48 ++++++++++++++++++++++++++-
 2 files changed, 66 insertions(+), 1 deletion(-)
 create mode 100644 config/initializers/i18n_pluralize.rb

diff --git a/config/initializers/i18n_pluralize.rb b/config/initializers/i18n_pluralize.rb
new file mode 100644
index 000000000..609a14ad7
--- /dev/null
+++ b/config/initializers/i18n_pluralize.rb
@@ -0,0 +1,19 @@
+### From official I18n::Backend::Base
+### https://github.com/svenfuchs/i18n/blob/f35b839693c5ecc7ea0ff0f57c5cbf6db1dd73f9/lib/i18n/backend/base.rb#L155
+### Just changed one line to return `count` instead of raising the exception `InvalidPluralizationData`
+
+module I18n
+  module Backend
+    module Base
+
+      def pluralize(locale, entry, count)
+        return entry unless entry.is_a?(Hash) && count
+
+        key = pluralization_key(entry, count)
+        return count unless entry.has_key?(key)
+        entry[key]
+      end
+
+    end
+  end
+end
\ No newline at end of file
diff --git a/spec/i18n_spec.rb b/spec/i18n_spec.rb
index 5237b7240..7fb59edde 100644
--- a/spec/i18n_spec.rb
+++ b/spec/i18n_spec.rb
@@ -1,6 +1,7 @@
+require 'rails_helper'
 require 'i18n/tasks'
 
-RSpec.describe 'I18n' do
+describe 'I18n' do
   let(:i18n) { I18n::Tasks::BaseTask.new }
   let(:missing_keys) { i18n.missing_keys }
   let(:unused_keys) { i18n.unused_keys }
@@ -14,4 +15,49 @@ RSpec.describe 'I18n' do
     expect(unused_keys).to be_empty,
       "#{unused_keys.leaves.count} unused i18n keys, run `i18n-tasks unused' to show them"
   end
+
+  context "Plurals" do
+
+    after do
+      I18n.backend.reload!
+    end
+
+    it "returns plural rule if translation present" do
+      keys = { zero:  "No comments",
+               one:   "1 comment",
+               other: "%{count} comments" }
+
+      I18n.backend.store_translations(:en, { test_plural: keys })
+
+      expect(I18n.t("test_plural", count: 0)).to eq("No comments")
+      expect(I18n.t("test_plural", count: 1)).to eq("1 comment")
+      expect(I18n.t("test_plural", count: 2)).to eq("2 comments")
+    end
+
+    it "returns default locale's plural rule if whole translation not present" do
+      keys = { zero:  "No comments",
+               one:   "1 comment",
+               other: "%{count} comments" }
+
+      I18n.backend.store_translations(I18n.default_locale, { test_plural: keys })
+      I18n.backend.store_translations(:zz, {} )
+
+      I18n.enforce_available_locales = false
+      I18n.locale = :zz
+
+      expect(I18n.t("test_plural", count: 0)).to eq("No comments")
+      expect(I18n.t("test_plural", count: 1)).to eq("1 comment")
+      expect(I18n.t("test_plural", count: 2)).to eq("2 comments")
+    end
+
+    it "returns count if specific plural rule not present" do
+      keys = { zero:  "No comments" }
+      I18n.backend.store_translations(:en, { test_plural: keys })
+
+      expect(I18n.t("test_plural", count: 0)).to eq("No comments")
+      expect(I18n.t("test_plural", count: 1)).to eq(1)
+      expect(I18n.t("test_plural", count: 2)).to eq(2)
+    end
+
+  end
 end