Updates in order to be compatible with versions of Ruby < 2.3.0

cyclonedx-ruby.gemspec

@@ -11,8 +11,8 @@ Gem::Specification.new do |spec|
   spec.license     = "Apache-2.0"
   spec.executables << "cyclonedx-ruby"
   spec.add_dependency('json', '~> 2.2')
-  spec.add_dependency('nokogiri', '~> 1.8')
-  spec.add_dependency('ostruct', '~> 0.1')
+  spec.add_dependency('rexml', '~> 3.2')
+  spec.add_dependency('bundler', '~> 1.17')
   spec.add_dependency('rest-client', '~> 2.0')
   spec.add_development_dependency 'rake', '~> 12'
   spec.add_development_dependency 'rspec', '~> 3.7'

lib/bom_builder.rb

@@ -2,10 +2,10 @@
 require "fileutils"
 require "json"
 require "logger"
-require "nokogiri"
 require "optparse"
 require "ostruct"
 require "rest_client"
+require "rexml/document"
 require 'securerandom'
 require_relative "bom_helpers"
 

lib/bom_helpers.rb

@@ -7,48 +7,70 @@ def random_urn_uuid()
 end
 
 def build_bom(gems)
-  builder = Nokogiri::XML::Builder.new(:encoding => "UTF-8") do |xml|
-    attributes = {"xmlns" => "http://cyclonedx.org/schema/bom/1.1", "version" => "1", "serialNumber" => random_urn_uuid}
-    xml.bom(attributes) do
-      xml.components {
-        gems.each do |gem|
-          xml.component("type" => "library") {
-            xml.name gem["name"]
-            xml.version gem["version"]
-            xml.description gem["description"]
-            xml.hashes{
-              xml.hash_ gem["hash"], :alg => "SHA-256"
-            }
-            if gem["license_id"]
-              xml.licenses {
-                xml.license{
-                  xml.id gem["license_id"]
-                }
-              } 
-            elsif gem["license_name"]
-              xml.licenses {
-                xml.license{
-                  xml.name gem["license_name"]
-                }
-              }
-            end
-            xml.purl gem["purl"]
-          }
-        end
-      }
+
+  xml_doc = REXML::Document.new('<?xml version="1.0" encoding="UTF-8"?>')
+  bom_xml_element = xml_doc.add_element "bom", {"xmlns" => "http://cyclonedx.org/schema/bom/1.0", "version"=>"1", "serialNumber" => random_urn_uuid}
+  components_xml_element = bom_xml_element.add_element "components"
+
+  gems.each do |gem|
+    component_xml_element = components_xml_element.add_element "component", {"type" => "library"}
+
+    name_xml_element = component_xml_element.add_element "name"
+    name_xml_element.text = gem["name"]
+
+    version_xml_element = component_xml_element.add_element "version"
+    version_xml_element.text = gem["version"]
+
+    description_xml_element = component_xml_element.add_element "description"
+    description_xml_element.text = gem["description"]
+
+    hashes_xml_element = component_xml_element.add_element "hashes"
+    hash_xml_element = hashes_xml_element.add_element "hash", {"alg" => "SHA-256"}
+    hash_xml_element.text = gem["hash"]
+
+    if gem["license_id"] || gem["license_name"]
+      licenses_xml_element = component_xml_element.add_element "licenses"
+
+      license_xml_element = licenses_xml_element.add_element "license"
+
+      if gem["license_id"]
+        license_id_xml_element = license_xml_element.add_element "id"
+        license_id_xml_element.text = gem["license_id"]
+      elsif gem["license_name"]
+        license_name_xml_element = license_xml_element.add_element "id"
+        license_name_xml_element.text = gem["license_name"]
+      end
     end
-  end 
-  builder.to_xml
-end 
+
+    purl_xml_element = component_xml_element.add_element "purl"
+    purl_xml_element.text = gem["purl"]
+  end
+
+  output=""
+  xml_doc.write(output=output)
+  output
+end
 
 def get_gem(name, version)
   url = "https://rubygems.org/api/v1/versions/#{name}.json"
+  max_retries = 3
+  retry_count = 0
+  delay = 1
+
   begin
     response = RestClient.get(url)
     body = JSON.parse(response.body)
-    body.select {|item| item["number"] == version.to_s}.first
-  rescue 
-    @logger.warn("#{name} couldn't be fetched")
-    return nil
+    gem_details = body.select {|item| item["number"] == version.to_s}.first
+    return gem_details if gem_details
+  rescue => e
+    if max_retries > retry_count
+        @logger.warn("gem #{name} could NOT be fetched. Error was: #{e.message}. Retrying #{max_retries - retry_count} more time(s)...")
+        sleep delay + retry_count
+        retry_count += 1
+        retry
+    else
+        @logger.warn("gem #{name} could NOT be fetched. Error was: #{e.message}. Gave up after retrying #{max_retries} times!")
+        return nil
+    end
   end
-end 
+end