Don't install gems in development and production groups on Travis.

Cache gems on Travis.
Don't run Antivirus spec tests if Antivirus is not installed.

.travis.yml

@@ -3,6 +3,8 @@ rvm:
   - 2.0.0
 before_script:
   - "cp config/log4r.yml.sample config/log4r.yml"
+bundler_args: --without development production --deployment
+cache: bundler
 script: "bundle exec rake dul_hydra:ci:build"
 notifications:
   email:

Gemfile

@@ -12,7 +12,10 @@ gem 'grouper-rest-client'
 gem 'hydra-editor', '0.2.2'
 gem 'hydra-derivatives'
 gem 'deprecation'
-gem 'clamav'
+
+group :production, :development do
+  gem 'clamav'
+end
 
 gem 'sqlite3'
 gem 'log4r'

lib/dul_hydra/services/antivirus.rb

@@ -1,5 +1,3 @@
-require 'clamav'
-
 module DulHydra
   module Services
     class Antivirus
@@ -8,79 +6,60 @@ class AntivirusError < DulHydra::Error; end
       class VirusFoundError < AntivirusError; end
       class AntivirusEngineError < AntivirusError; end
 
-      class ScanResult
-
-        attr_reader :raw, :file, :scanned_at, :version
-
-        def initialize(raw, file, opts={})
-          @raw = raw
-          @file = file
-          @scanned_at = opts.fetch(:scanned_at, DateTime.now)
-          @version = opts.fetch(:version, DulHydra::Services::Antivirus.version)
-        end
-
-        def virus_found
-          raw if raw.is_a? String
-        end
-
-        def has_virus?
-          !virus_found.nil?
-        end
-
-        def status
-          if has_virus?
-            "FOUND #{virus_found}"
-          else
-            "OK"
-          end
-        end
-
-        def error?
-          raw == 1
-        end
-
-        def to_s
-          "Virus scan: #{status} - #{file} (#{version})"
-        end
-
-      end
-
       class << self
-
-        def init
-          engine.loaddb
-        end
-
         def scan(file)
           result = scan_one file
-          if result.has_virus?
-            raise VirusFoundError, result
-          end
+          raise VirusFoundError, result if result.has_virus?
           raise AntivirusEngineError, result.version if result.error?
           logger.info result
           result
         end
 
+        def scan_one(file)
+          load! unless loaded?
+          path = get_file_path file
+          raw_result = engine.scanfile path
+          ScanResult.new raw_result, path
+        end
+
+        def load!
+          raise DulHydra::Error, "Antivirus is not installed." unless installed?
+          load
+        end
+
         def version
+          # ClamAV sigtool may be installed on system,
+          # but we require that clamav gem is installed.
+          return unless installed?
           # Engine and database versions
           # E.g., ClamAV 0.98.3/19010/Tue May 20 21:46:01 2014
           `sigtool --version`.strip
         end
 
-        def reload
-          # Reload virus database if changed
-          #   1 - reload successful
-          #   0 - reload unnecessary        
-          engine.reload == 1
+        def installed?
+          @installed ||= begin
+                           require 'clamav'
+                         rescue LoadError
+                           false
+                         else
+                           true
+                         end
         end
 
-        def scan_one(file)
-          path = get_file_path file
-          raw_result = engine.scanfile path
-          ScanResult.new raw_result, path
+        private
+
+        def loaded!
+          @loaded = true
         end
 
-        private
+        def loaded?
+          !@loaded.nil?
+        end
+
+        def load
+          engine.loaddb
+          loaded!
+        end
 
         def get_file_path(file)
           path = if file.is_a? String
@@ -96,11 +75,43 @@ def get_file_path(file)
         def engine
           ClamAV.instance
         end
-
+      end
+
+      class ScanResult
+        attr_reader :raw, :file, :scanned_at, :version
+
+        def initialize(raw, file, opts={})
+          @raw = raw
+          @file = file
+          @scanned_at = opts.fetch(:scanned_at, DateTime.now)
+          @version = opts.fetch(:version, DulHydra::Services::Antivirus.version)
+        end
+
+        def virus_found
+          raw if raw.is_a? String
+        end
+
+        def has_virus?
+          !virus_found.nil?
+        end
+
+        def status
+          if has_virus?
+            "FOUND #{virus_found}"
+          else
+            "OK"
+          end
+        end
+
+        def error?
+          raw == 1
+        end
+
+        def to_s
+          "Virus scan: #{status} - #{file} (#{version})"
+        end
       end
 
     end
   end
 end
-
-DulHydra::Services::Antivirus.init

spec/services/antivirus_spec.rb

@@ -1,6 +1,10 @@
 require 'spec_helper'
 
-describe DulHydra::Services::Antivirus do
+def installed?
+  DulHydra::Services::Antivirus.installed?
+end
+
+describe DulHydra::Services::Antivirus, if: installed? do
   let(:file) { fixture_file_upload "library-devil.tiff" }
   it "should report whether a file is infected" do
     expect(described_class.scan(file)).not_to have_virus