Fix: #370 ダブルクオートを使った日本語検索が効かない (#448)

* Fix: #370 ダブルクオートを使った日本語検索が効かない

* Add test for multiple words

* Improve test

* 入れ替え

* 単語検索のテスト

spec/search/services/statuses_search_service_spec.rb

@@ -213,4 +213,54 @@ describe StatusesSearchService do
       end
     end
   end
+
+  describe 'a local user posts with search keyword' do
+    subject do
+      described_class.new.call(search_keyword, account, limit: 10).map(&:id)
+    end
+
+    let(:search_keyword) { 'ohagi' }
+    let(:status_text) { 'りんごを食べました' }
+
+    let(:alice) { Fabricate(:user).account }
+    let(:account) { alice }
+    let!(:status) { Fabricate(:status, text: status_text, account: alice, searchability: :public) }
+
+    before do
+      alice.update!(username: 'alice')
+      StatusesIndex.import!
+    end
+
+    shared_examples 'hit status' do |name, keyword|
+      context name do
+        let(:search_keyword) { keyword }
+
+        it 'a status hits' do
+          expect(subject.count).to eq 1
+          expect(subject).to include status.id
+        end
+      end
+    end
+
+    shared_examples 'does not hit status' do |name, keyword|
+      context name do
+        let(:search_keyword) { keyword }
+
+        it 'no statuses hit' do
+          expect(subject.count).to eq 0
+        end
+      end
+    end
+
+    it_behaves_like 'hit status', 'when search with word', 'りんご'
+    it_behaves_like 'hit status', 'when search with multiple words', 'りんご 食べる'
+    it_behaves_like 'does not hit status', 'when search with multiple words but does not hit half', 'りんご 茹でる'
+    it_behaves_like 'hit status', 'when search with letter in word', 'ご'
+    it_behaves_like 'does not hit status', 'when double quote search with letter in word', '"ご"'
+    it_behaves_like 'hit status', 'when search with fixed word', '"りんご"'
+    it_behaves_like 'hit status', 'when double quote search with multiple letter in word', 'り ご'
+    it_behaves_like 'does not hit status', 'when double quote search with multiple letter in word but does not contain half', 'ず ご'
+    it_behaves_like 'hit status', 'when specify user name', 'りんご from:alice'
+    it_behaves_like 'does not hit status', 'when specify not existing user name', 'りんご from:ohagi'
+  end
 end