Get search dictionary based on I18n.default_locale (merge pull request #3856)

Implementation tries to be open for further extensions, such as deciding on
search dictionary based on configuration option or by locale set for
given user.

app/models/concerns/search_cache.rb

@@ -19,7 +19,8 @@ module SearchCache
     end
 
     def set_tsvector(value, weight)
-      "setweight(to_tsvector('spanish', unaccent(coalesce(#{quote(strip_html(value))}, ''))), #{quote(weight)})"
+      dict = quote(SearchDictionarySelector.call)
+      "setweight(to_tsvector(#{dict}, unaccent(coalesce(#{quote(strip_html(value))}, ''))), #{quote(weight)})"
     end
 
     def quote(value)

app/models/concerns/searchable.rb

@@ -5,14 +5,18 @@ module Searchable
     include PgSearch
     include SearchCache
 
-    pg_search_scope :pg_search, {
+    pg_search_scope :pg_search, ->(query) do
+      cached_votes_up_present = column_names.include?("cached_votes_up")
+      {
         against: :ignored, # not used since using a tsvector_column
         using: {
-        tsearch: { tsvector_column: "tsv", dictionary: "spanish", prefix: true }
+          tsearch: { tsvector_column: "tsv", dictionary: SearchDictionarySelector.call, prefix: true }
         },
         ignoring: :accents,
         ranked_by: "(:tsearch)",
-      order_within_rank: (column_names.include?("cached_votes_up") ? "#{table_name}.cached_votes_up DESC" : nil)
+        order_within_rank: (cached_votes_up_present ? "#{table_name}.cached_votes_up DESC" : nil),
+        query: query
       }
     end
   end
+end

lib/search_dictionary_selector.rb

@@ -0,0 +1,42 @@
+module SearchDictionarySelector
+  SQL_QUERY = "SELECT cfgname FROM pg_ts_config".freeze
+  I18N_TO_DICTIONARY = {
+    en: "english",
+    de: "german",
+    fi: "finnish",
+    fr: "french",
+    dk: "danish",
+    nl: "dutch",
+    hu: "hungarian",
+    it: "italian",
+    nn: "norwegian",
+    nb: "norwegian",
+    pt: "portuguese",
+    ro: "romanian",
+    ru: "russian",
+    es: "spanish",
+    sv: "swedish",
+    tr: "turkish"
+  }.freeze
+
+  class << self
+    def call
+      find_from_i18n_default
+    end
+
+    private
+
+      def find_from_i18n_default
+        key_to_lookup = I18n.default_locale.to_s.split("-").first.to_sym
+
+        dictionary = I18N_TO_DICTIONARY[key_to_lookup]
+        dictionary ||= "simple"
+        available_dictionaries.include?(dictionary) ? dictionary : available_dictionaries.first
+      end
+
+      def available_dictionaries
+        result = ActiveRecord::Base.connection.execute(SQL_QUERY)
+        result.to_a.map { |row| row["cfgname"] }
+      end
+  end
+end

spec/features/proposals_spec.rb

@@ -1410,7 +1410,7 @@ describe "Proposals" do
       end
     end
 
-    scenario "Order by relevance by default", :js do
+    scenario "Order by relevance by default", :spanish_search, :js do
       create(:proposal, title: "Show you got",      cached_votes_up: 10)
       create(:proposal, title: "Show what you got", cached_votes_up: 1)
       create(:proposal, title: "Show you got",      cached_votes_up: 100)

spec/lib/search_dictionary_selector_spec.rb

@@ -0,0 +1,30 @@
+require "rails_helper"
+
+describe SearchDictionarySelector do
+  context "from I18n default locale" do
+    before { allow(subject).to receive(:call).and_call_original }
+    around do |example|
+      original_i18n_default = I18n.default_locale
+      begin
+        example.run
+      ensure
+        I18n.default_locale = original_i18n_default
+      end
+    end
+
+    it "returns correct dictionary for simple locale" do
+      I18n.default_locale = :es
+      expect(subject.call).to eq("spanish")
+    end
+
+    it "returns correct dictionary for compound locale" do
+      I18n.default_locale = :"pt-BR"
+      expect(subject.call).to eq("portuguese")
+    end
+
+    it "returns simple for unsupported locale" do
+      expect(I18n).to receive(:default_locale).and_return(:pl) # avoiding I18n::InvalidLocale
+      expect(subject.call).to eq("simple")
+    end
+  end
+end

spec/models/debate_spec.rb

@@ -503,7 +503,7 @@ describe Debate do
     end
 
     context "stemming" do
-      it "searches word stems" do
+      it "searches word stems in Spanish", :spanish_search do
         debate = create(:debate, title: "limpiar")
 
         results = Debate.search("limpiará")

spec/models/proposal_spec.rb

@@ -558,7 +558,7 @@ describe Proposal do
     end
 
     context "case" do
-      it "searches case insensite" do
+      it "searches case insensitive" do
         proposal = create(:proposal, title: "SHOUT")
 
         results = Proposal.search("shout")

spec/spec_helper.rb

@@ -128,6 +128,10 @@ RSpec.configure do |config|
     allow(Time).to receive(:zone).and_return(application_zone)
   end
 
+  config.before(:each, :spanish_search) do |example|
+    allow(SearchDictionarySelector).to receive(:call).and_return("spanish")
+  end
+
   # Allows RSpec to persist some state between runs in order to support
   # the `--only-failures` and `--next-failure` CLI options.
   config.example_status_persistence_file_path = "spec/examples.txt"