diff --git a/spec/create_spec.rb b/spec/create_spec.rb
index 4ef0610..140af0b 100644
--- a/spec/create_spec.rb
+++ b/spec/create_spec.rb
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 require 'simplecov'
 SimpleCov.start
 
 require_relative '../.env'
-ENV["DB_NAME"] = "test_#{ENV["DB_NAME"]}"
+ENV['DB_NAME'] = "test_#{ENV.fetch('DB_NAME', nil)}"
 require_relative '../app'
 require 'rubygems'
 require 'roda'
@@ -12,48 +14,47 @@ require 'rack/test'
 
 # DB initialization
 Sequel.extension :migration
-Sequel.sqlite("db/#{ENV['DB_NAME']}") do |db|
-  Sequel::Migrator.apply(db, "db/migrations")
+Sequel.sqlite("db/#{ENV.fetch('DB_NAME', nil)}") do |db|
+  Sequel::Migrator.apply(db, 'db/migrations')
 end
 
 def app
   App
 end
 
-describe "Submit API request to create new link" do
+describe 'Submit API request to create new link' do
   include Rack::Test::Methods
   before :each do
-    @links = Sequel.sqlite("db/#{ENV['DB_NAME']}")[:links]
+    @links = Sequel.sqlite("db/#{ENV.fetch('DB_NAME', nil)}")[:links]
   end
   after :each do
     @links.delete
   end
-  it "should return link data in json format when a valid url is submitted" do
+  it 'should return link data in json format when a valid url is submitted' do
     data = {
       url: 'http://google.com'
     }
-    post('/links', data.to_json, "CONTENT_TYPE" => "application/json")
+    post('/links', data.to_json, 'CONTENT_TYPE' => 'application/json')
     expect(last_response).to be_ok
     response_json = JSON.parse(last_response.body)
     expect(response_json['url']).to eq(data[:url])
     expect(response_json['code']).not_to eq(nil)
     expect(response_json['link']).to include(response_json['code'])
   end
-  
+
   it "should return with a 400 status and 'invalid url parameter' message when an empty url is submitted" do
     data = {
       url: ''
     }
-    post('/links', data.to_json, "CONTENT_TYPE" => "application/json")
+    post('/links', data.to_json, 'CONTENT_TYPE' => 'application/json')
     expect(last_response.status).to eq(400)
     response_json = JSON.parse(last_response.body)
     expect(response_json['message']).to eq('invalid url parameter')
   end
 
   it "should return with a 400 status and 'missing url parameter' message when an empty url is submitted" do
-    data = {
-    }
-    post('/links', data.to_json, "CONTENT_TYPE" => "application/json")
+    data = {}
+    post('/links', data.to_json, 'CONTENT_TYPE' => 'application/json')
     expect(last_response.status).to eq(400)
     response_json = JSON.parse(last_response.body)
     expect(response_json['message']).to eq('missing url parameter')
@@ -63,7 +64,7 @@ describe "Submit API request to create new link" do
     data = {
       url: 'not-an-url'
     }
-    post('/links', data.to_json, "CONTENT_TYPE" => "application/json")
+    post('/links', data.to_json, 'CONTENT_TYPE' => 'application/json')
     expect(last_response.status).to eq(400)
     response_json = JSON.parse(last_response.body)
     expect(response_json['message']).to eq('invalid url parameter')
@@ -73,7 +74,7 @@ describe "Submit API request to create new link" do
     data = {
       url: 'http://google.com/example'
     }
-    post('/links', data.to_json, "CONTENT_TYPE" => "application/json")
+    post('/links', data.to_json, 'CONTENT_TYPE' => 'application/json')
     expect(last_response.status).to eq(400)
     response_json = JSON.parse(last_response.body)
     expect(response_json['message']).to eq('url not found')
@@ -83,13 +84,14 @@ describe "Submit API request to create new link" do
     data = {
       url: 'http://bad.tld'
     }
-    post('/links', data.to_json, "CONTENT_TYPE" => "application/json")
+    post('/links', data.to_json, 'CONTENT_TYPE' => 'application/json')
     expect(last_response.status).to eq(400)
     response_json = JSON.parse(last_response.body)
     expect(response_json['message']).to eq('url does not resolve')
   end
 
-  it "should return with a 400 status and 'not a valid json request' message when a request is made with the wrong content type header" do
+  it "should return with a 400 status and 'not a valid json request'
+      message when a request is made with the wrong content type header" do
     data = {
       url: 'http://google.com'
     }