Resolved issue #3. Error handling for some exception cases

README.md

@@ -1,5 +1,5 @@
 # BcnNi
-This gem provides NIO (Córdoba oro Nicaragüense) versus USD (United States dollar) money exchange rates consuming the official Central Bank of Nicaragüa (BCN) SOAP Service
+This gem provides NIO (Córdoba Oro Nicaragüense) against USD (United States Dollar) money exchange rates consuming the official Central Bank of Nicaragüa (BCN) SOAP Service or HTML page
 
 ## Basic usage
 ```ruby
@@ -67,7 +67,7 @@ Add this line to your application's Gemfile:
 gem 'bcn_ni', git: 'https://github.com/mldoscar/bcn_ni', branch: 'master'
 
 # From ruby gems
-gem 'bcn_ni', '>= 0.1.3'
+gem 'bcn_ni', '>= 0.1.4'
 
 # Using gem install
 gem install bcn_ni

bcn_ni.gemspec

@@ -10,14 +10,14 @@ Gem::Specification.new do |s|
   s.authors     = ["Oscar Rodriguez"]
   s.email       = ["[email protected]"]
   s.homepage    = "https://github.com/mldoscar/bcn_ni"
-  s.summary     = "This gem provides NIO (Córdoba oro Nicaragüense) versus USD (United States dollar) money exchange rates consuming the official Central Bank of Nicaragüa (BCN) SOAP Service"
-  s.description = "This tool pretends to be helpful for developers who can request exchange rates in a easier way"
+  s.summary     = "This tool pretends to be helpful for developers who can request exchange rates from Nicaragua in a easier way"
+  s.description = "This gem provides NIO (Córdoba Oro Nicaragüense) against USD (United States Dollar) money exchange rates consuming the official Central Bank of Nicaragüa (BCN) SOAP Service or HTML page"
   s.license     = "MIT"
 
   s.files = Dir["{app,config,db,lib}/**/*", "MIT-LICENSE", "Rakefile", "README.md", "CODE_OF_CONDUCT.md"]
 
-  s.add_dependency "activesupport", "~> 5.1", ">= 5.1.3"
-  s.add_dependency "nokogiri",      "~> 1.10"
+  s.add_dependency "activesupport", ">= 5.2"
+  s.add_dependency "nokogiri",      ">= 1.6"
 
   s.add_development_dependency "rake",  "~> 12.3"
   s.add_development_dependency "rspec", "~> 3.8"

lib/bcn_ni/core.rb

@@ -1,15 +1,27 @@
 module BcnNi
   require File.expand_path(File.dirname(__FILE__)) + '/helpers/request'
 
+  @@exceptions  = []
+
   def self.exchange_month(year, month, args = {})
-    request = BcnNi::Request.new(args)
+    engine        = BcnNi::Request.new(args)
+
+    result        = engine.exchange_month(year, month)
+    @@exceptions  = engine.exceptions
 
-    return request.exchange_month(year, month)
+    return result
   end
 
   def self.exchange_day(year, month, day, args = {})
-    request = BcnNi::Request.new(args)
+    engine        = BcnNi::Request.new(args)
+
+    result        = engine.exchange_day(year, month, day)
+    @@exceptions  = engine.exceptions
+
+    return result
+  end
 
-    return request.exchange_day(year, month, day)
+  def self.exceptions
+    return @@exceptions
   end
 end

lib/bcn_ni/helpers/request.rb

@@ -8,11 +8,25 @@
 
 module BcnNi
   class Request
-    @request_url  = ""
+    @request_url  = nil
     @request_mode = nil
+    @exceptions   = nil
+
+    def request_url
+      return @request_url
+    end
+
+    def request_mode
+      return @request_mode
+    end
+
+    def exceptions
+      return @exceptions
+    end
 
     def initialize(args = {})
       @request_mode = (args[:request_mode] || :scrapping).to_sym
+      @exceptions   = []
 
       case @request_mode
       when :scrapping
@@ -21,37 +35,43 @@ def initialize(args = {})
         # See 'https://servicios.bcn.gob.ni/Tc_Servicio/ServicioTC.asmx' for more info about how to build a RAW SOAP request
         @request_url = "https://servicios.bcn.gob.ni/Tc_Servicio/ServicioTC.asmx?WSDL"
       else
-        raise Exception.new('Request mode not implemented')
+        raise NotImplementedError, 'Request mode not implemented'
       end
     end
 
-    def request_url
-      return @request_url
-    end
-
-    def request_mode
-      return @request_mode
-    end
-
     def exchange_month(year, month)
-      case request_mode
-      when :scrapping
-        return scra__exchange_month(year, month)
-      when :soap
-        return soap__exchange_month(year, month)
-      else
-        raise Exception.new('Request mode not implemented')
+      begin
+        # Evaluate scrapping mode to call the correct method for processing the request
+        case request_mode
+        when :scrapping
+          return scra__exchange_month(year, month)
+        when :soap
+          return soap__exchange_month(year, month)
+        end
+      rescue Exception => e
+        # Save the exception into the exception list for future error messages or debugging
+        @exceptions.push e
+
+        # Return an empty value according to the called method
+        return []
       end
     end
 
     def exchange_day(year, month, day)
-      case request_mode
-      when :scrapping
-        return scra__exchange_day(year, month, day)
-      when :soap
-        return soap__exchange_day(year, month, day)
-      else
-        raise Exception.new('Request mode not implemented')
+      begin
+        # Evaluate scrapping mode to call the correct method for processing the request
+        case request_mode
+        when :scrapping
+          return scra__exchange_day(year, month, day)
+        when :soap
+          return soap__exchange_day(year, month, day)
+        end
+      rescue Exception => e
+        # Save the exception into the exception list for future error messages or debugging
+        @exceptions.push e
+
+        # Return an empty value according to the called method
+        return nil
       end
     end
 
@@ -69,9 +89,27 @@ def scra__exchange_month(year, month)
 
         # Generate the full url
         full_url = request_url + '?' + args.to_param
+
+        # This loop prevents a random EOFError (main cause is not known yet)
+        retries   = 0
+        response  = nil
+        while true
+          # Raise an error if too many retries
+          raise StopIteration if retries >= 5
+
+          begin
+            response = open(full_url, { ssl_verify_mode: OpenSSL::SSL::VERIFY_NONE })
+            # Exit loop if response has been assigned
+            break
+          rescue EOFError => e
+            # Sum retry and sleep the thread for a while
+            retries += 1
+            sleep(2.seconds)
+          end
+        end
 
-        # Fetch and parse HTML document
-        doc = Nokogiri::HTML(open(full_url, { ssl_verify_mode: OpenSSL::SSL::VERIFY_NONE }))
+        # Parse the HTML document
+        doc = Nokogiri::HTML(response)
 
         result = []
         # Iterate table

lib/bcn_ni/version.rb

@@ -1,3 +1,3 @@
 module BcnNi
-  VERSION = '0.1.3'
+  VERSION = '0.1.4'
 end

spec/bcn_ni/bcn_ni_spec.rb

@@ -8,6 +8,7 @@
 
     expected_rate = 30.3537
 
+    expect(BcnNi.exceptions).to be_empty
     expect(exchange_rate).to eq expected_rate
   end
 
@@ -48,6 +49,7 @@
       {:date=> Date.parse('2017-09-30'), :value=>30.4146}
     ]
 
+    expect(BcnNi.exceptions).to be_empty
     expect(exchange_table).to eq expected_table
   end
 end