refactoring the code

Gemfile

@@ -1,5 +1,7 @@
 source 'http://rubygems.org'
 
+ruby '3.2.0'
+
 gem 'sinatra'
 gem 'json'
 gem 'rack'
@@ -10,6 +12,6 @@ gem 'rubysl-base64'
 
 # These are the dependencies that are used only for unit tests.
 group :test do
-  gem "rspec"
-  gem "rack-test"
+  gem 'rspec'
+  gem 'rack-test'
 end

Rakefile

@@ -4,4 +4,4 @@ RSpec::Core::RakeTask.new :specs do |task|
   task.pattern = Dir['spec/**/*_spec.rb']
 end
 
-task :default => ['specs']
+task default: ['specs']

app/config.ru

@@ -1,8 +1,8 @@
 require 'rack'
 require 'rack/contrib'
-require_relative './server'
+require_relative 'server'
 
 set :root, File.dirname(__FILE__)
-set :views, Proc.new { File.join(root, "views") }
+set :views, proc { File.join(root, 'views') }
 
 run Sinatra::Application

app/server.rb

@@ -2,7 +2,7 @@
 require 'aws-record'
 
 before do
-  if (request.body && request.body.read.empty? && request.body.size > 0)
+  if request.body && request.body.read.empty? && request.body.size.positive?
     request.body.rewind
     @params = Sinatra::IndifferentHash.new
     @params.merge!(JSON.parse(request.body.read))
@@ -21,12 +21,12 @@
 ##################################
 get '/hello-world' do
   content_type :json
-  { :Output => 'Hello World!' }.to_json
+  { Output: 'Hello World!' }.to_json
 end
 
 post '/hello-world' do
-    content_type :json
-    { :Output => 'Hello World!' }.to_json
+  content_type :json
+  { Output: 'Hello World!' }.to_json
 end
 
 ##################################
@@ -49,11 +49,11 @@ class FeedbackServerlessSinatraTable
 
 get '/api/feedback' do
   content_type :json
-  items = FeedbackServerlessSinatraTable.scan()
-  items
-    .map { |r| { :ts => r.ts, :name => r.name, :feedback => r.feedback } }
-    .sort { |a, b| a[:ts] <=> b[:ts] }
-    .to_json
+  items = FeedbackServerlessSinatraTable.scan
+  items.
+    map { |r| { ts: r.ts, name: r.name, feedback: r.feedback } }.
+    sort { |a, b| a[:ts] <=> b[:ts] }.
+    to_json
 end
 
 post '/api/feedback' do

lambda.rb

@@ -22,14 +22,13 @@
 $app ||= Rack::Builder.parse_file("#{__dir__}/app/config.ru").first
 ENV['RACK_ENV'] ||= 'production'
 
-
 def handler(event:, context:)
   # Check if the body is base64 encoded. If it is, try to decode it
   body = if event['isBase64Encoded']
-    Base64.decode64 event['body']
-  else
-    event['body']
-  end || ''
+           Base64.decode64 event['body']
+         else
+           event['body']
+         end || ''
 
   # Rack expects the querystring in plain text, not a hash
   headers = event.fetch 'headers', {}
@@ -39,14 +38,14 @@ def handler(event:, context:)
     'REQUEST_METHOD' => event.fetch('httpMethod'),
     'SCRIPT_NAME' => '',
     'PATH_INFO' => event.fetch('path', ''),
-    'QUERY_STRING' => (event['queryStringParameters'] || {}).map { |k,v| "#{k}=#{v}" }.join('&'),
+    'QUERY_STRING' => (event['queryStringParameters'] || {}).map { |k, v| "#{k}=#{v}" }.join('&'),
     'SERVER_NAME' => headers.fetch('Host', 'localhost'),
     'SERVER_PORT' => headers.fetch('X-Forwarded-Port', 443).to_s,
 
     'rack.version' => Rack::VERSION,
     'rack.url_scheme' => headers.fetch('CloudFront-Forwarded-Proto') { headers.fetch('X-Forwarded-Proto', 'https') },
     'rack.input' => StringIO.new(body),
-    'rack.errors' => $stderr,
+    'rack.errors' => $stderr
   }
 
   # Pass request headers to Rack if they are available
@@ -55,11 +54,11 @@ def handler(event:, context:)
     # Content-Type and Content-Length are handled specially per the Rack SPEC linked above.
     name = key.upcase.gsub '-', '_'
     header = case name
-      when 'CONTENT_TYPE', 'CONTENT_LENGTH'
-        name
-      else
-        "HTTP_#{name}"
-    end
+             when 'CONTENT_TYPE', 'CONTENT_LENGTH'
+               name
+             else
+               "HTTP_#{name}"
+             end
     env[header] = value.to_s
   end
 
@@ -68,7 +67,7 @@ def handler(event:, context:)
     status, headers, body = $app.call env
 
     # body is an array. We combine all the items to a single string
-    body_content = ""
+    body_content = ''
     body.each do |item|
       body_content += item.to_s
     end
@@ -80,15 +79,15 @@ def handler(event:, context:)
       'headers' => headers,
       'body' => body_content
     }
-    if event['requestContext'].has_key?('elb')
+    if event['requestContext'].key?('elb')
       # Required if we use Application Load Balancer instead of API Gateway
       response['isBase64Encoded'] = false
     end
-  rescue Exception => exception
+  rescue Exception => e
     # If there is _any_ exception, we return a 500 error with an error message
     response = {
       'statusCode' => 500,
-      'body' => exception.message
+      'body' => e.message
     }
   end
 

spec/server_spec.rb

@@ -5,52 +5,48 @@
   include Rack::Test::Methods
 
   # Test for HTTP GET for URL-matching pattern '/'
-  it "should return successfully on GET" do
+  it 'returns successfully on GET' do
     get '/hello-world'
     expect(last_response).to be_ok
     json_result = JSON.parse(last_response.body)
-    expect(json_result["Output"]).to eq("Hello World!")
+    expect(json_result['Output']).to eq('Hello World!')
   end
 
   # Test for HTTP POST for URL-matching pattern '/'
-  it "should return successfully on POST" do
+  it 'returns successfully on POST' do
     post '/hello-world'
     expect(last_response).to be_ok
-    expect(json_result["Output"]).to eq("Hello World!")
+    expect(json_result['Output']).to eq('Hello World!')
   end
 
-  it "should POST params to API feedback endpoint with success" do
-    expect(stub_client)
-      .to receive(:put_item)
-      .with({
-        :condition_expression=>be_kind_of(String),
-        :expression_attribute_names=>be_kind_of(Hash),
-        :item=>
-         {"feedback"=>"AWS Lambda + Ruby == <3",
-          "id"=>be_kind_of(String),
-          "name"=>"Tomas",
-          "ts"=>be_within(3).of(Time.now.to_i)},
-        :table_name=>"FeedbackServerlessSinatraTable"})
-      .and_call_original
-
-    api_gateway_post('/api/feedback', { name: "Tomas", feedback: "AWS Lambda + Ruby == <3" })
+  it 'POSTS params to API feedback endpoint with success' do
+    expect(stub_client).
+      to receive(:put_item).
+      with({
+             condition_expression: be_a(String),
+             expression_attribute_names: be_a(Hash),
+             item: { 'feedback' => 'AWS Lambda + Ruby == <3',
+                     'id' => be_a(String),
+                     'name' => 'Tomas',
+                     'ts' => be_within(3).of(Time.now.to_i) },
+             table_name: 'FeedbackServerlessSinatraTable'
+           }).
+      and_call_original
+
+    api_gateway_post('/api/feedback', { name: 'Tomas', feedback: 'AWS Lambda + Ruby == <3' })
 
     expect(last_response).to be_ok
   end
 
-  it "should successfuly GET items from API feedback endpoint in right order" do
-    stub_client.stub_responses(:scan, :items => [
-      {'name' => 'Zdenka', "ts" => 2345678, "feedback" => "Halestorm"},
-      {'name' => 'Tomas',  "ts" => 1234567, "feedback" => "Trivium"},
-      {'name' => 'xiangshen', "ts" => 5678901, "feedback" => "Awesome !"},
-    ])
+  it 'successfulies GET items from API feedback endpoint in right order' do
+    stub_client.stub_responses(:scan, items: [
+                                 { 'name' => 'Zdenka', 'ts' => 2_345_678, 'feedback' => 'Halestorm' },
+                                 { 'name' => 'Tomas', 'ts' => 1_234_567, 'feedback' => 'Trivium' },
+                                 { 'name' => 'xiangshen', 'ts' => 5_678_901, 'feedback' => 'Awesome !' }
+                               ])
 
     get '/api/feedback'
     expect(last_response).to be_ok
-    expect(json_result).to match_array([
-      { "name" => "Tomas",    "feedback"=>"Trivium",   "ts"=> be_kind_of(String)},
-      { "name" => "Zdenka",   "feedback"=>"Halestorm", "ts"=> be_kind_of(String)},
-      { "name" => "xiangshen","feedback"=>"Awesome !", "ts"=> be_kind_of(String)}
-    ])
+    expect(json_result).to contain_exactly({ 'name' => 'Tomas', 'feedback' => 'Trivium', 'ts' => be_a(String) }, { 'name' => 'Zdenka', 'feedback' => 'Halestorm', 'ts' => be_a(String) }, { 'name' => 'xiangshen', 'feedback' => 'Awesome !', 'ts' => be_a(String) })
   end
 end

spec/spec_helper.rb

@@ -1,10 +1,10 @@
-require_relative '../app/server.rb'
+require_relative '../app/server'
 require 'rack/test'
 
 set :environment, :test
 
 RSpec.configure do |config|
-  config.before(:each) do
+  config.before do
     FeedbackServerlessSinatraTable.configure_client(client: stub_client)
   end
 end
@@ -14,9 +14,7 @@ def app
 end
 
 def stub_client
-  @stub_client ||= begin
-    Aws::DynamoDB::Client.new(stub_responses: true) # don't send real calls to DynamoDB in test env
-  end
+  @stub_client ||= Aws::DynamoDB::Client.new(stub_responses: true) # don't send real calls to DynamoDB in test env
 end
 
 # We could use native RSpec `post '/endpoint', param1: 'foo', param2: 'bar'
@@ -27,7 +25,7 @@ def api_gateway_post(path, params)
   api_gateway_body_fwd = params.to_json
   rack_input = StringIO.new(api_gateway_body_fwd)
 
-  post path, real_params = {}, {"rack.input" => rack_input}
+  post path, {}, { 'rack.input' => rack_input }
 end
 
 def json_result