From b4aa3e5bd597ba814e89facafd3746c67f863f6c Mon Sep 17 00:00:00 2001
From: Alex Kotov <kotovalexarian@gmail.com>
Date: Sun, 30 Jan 2022 18:38:41 +0500
Subject: [PATCH] Ruby: add test cases

---
 pkgs/ruby/spec/lib/kernaux/itoa_spec.rb | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/pkgs/ruby/spec/lib/kernaux/itoa_spec.rb b/pkgs/ruby/spec/lib/kernaux/itoa_spec.rb
index f6f25b6..5bee60e 100644
--- a/pkgs/ruby/spec/lib/kernaux/itoa_spec.rb
+++ b/pkgs/ruby/spec/lib/kernaux/itoa_spec.rb
@@ -16,30 +16,40 @@ RSpec.describe KernAux, '.itoa' do
     context 'when number is 0' do
       let(:number) { 0 }
 
+      it { is_expected.to be_instance_of String }
+      it { is_expected.to be_frozen }
       it { is_expected.to eq '0' }
     end
 
     context 'when number is 1' do
       let(:number) { 1 }
 
+      it { is_expected.to be_instance_of String }
+      it { is_expected.to be_frozen }
       it { is_expected.to eq '1' }
     end
 
     context 'when number is -1' do
       let(:number) { -1 }
 
+      it { is_expected.to be_instance_of String }
+      it { is_expected.to be_frozen }
       it { is_expected.to eq '-1' }
     end
 
     context 'when number is min int64_t' do
       let(:number) { -2**63 }
 
+      it { is_expected.to be_instance_of String }
+      it { is_expected.to be_frozen }
       it { is_expected.to eq number.to_s base }
     end
 
     context 'when number is max int64_t' do
       let(:number) { 2**63 - 1 }
 
+      it { is_expected.to be_instance_of String }
+      it { is_expected.to be_frozen }
       it { is_expected.to eq number.to_s base }
     end