Simplify methods in FFprobe

Co-authored-by: Chris Colvard <[email protected]>

lib/avalon/ffprobe.rb

@@ -14,35 +14,42 @@
 
 module Avalon
   class FFprobe
-    attr_reader :json_output, :video_stream, :audio_stream
     # @param [FileLocator] media_file a file locator instance for the media file
     def initialize(media_file)
-      return @json_output = {} unless valid_content_type?(media_file)
+      @media_file = media_file
+    end
+
+    def json_output
+      return @json_output unless @json_output.nil?
+      return @json_output = {} unless valid_content_type?(@media_file)
       ffprobe = Settings&.ffprobe&.path || 'ffprobe'
-      raw_output = `#{ffprobe} -i "#{media_file.location}" -v quiet -show_format -show_streams -of json`
+      raw_output = `#{ffprobe} -i "#{@media_file.location}" -v quiet -show_format -show_streams -of json`
       # $? is a variable for the exit status of the last executed process. 
       # Success == 0, any other value means the command failed in some way.
       unless $?.exitstatus == 0
-        @json_output = {}
         Rails.logger.error "File processing failed. Please ensure that FFprobe is installed and that the correct path is configured."
-        return
+        return @json_output = {}
       end
       @json_output = JSON.parse(raw_output).deep_symbolize_keys
+      @json_output
+    end
 
-      @video_stream = json_output[:streams].select { |stream| stream[:codec_type] == 'video' }.first
-      @audio_stream = json_output[:streams].select { |stream| stream[:codec_type] == 'audio' }.first
+    def video_stream
+      return unless json_output.present?
+      @video_stream ||= json_output[:streams].select { |stream| stream[:codec_type] == 'video' }.first
     end
 
-    def video?
-      return true if video_stream
+    def audio_stream
+      return unless json_output.present?
+      @audio_stream ||= json_output[:streams].select { |stream| stream[:codec_type] == 'audio' }.first
+    end
 
-      false
+    def video?
+      video_stream.present?
     end
 
     def audio?
-      return true if audio_stream
-
-      false
+      audio_stream.present?
     end
 
     def duration
@@ -70,9 +77,8 @@ def valid_content_type? media_file
       extension = File.extname(media_file.location)&.gsub(/[\?#].*/, '')
       # Fall back on file extension if magic bytes fail to identify file
       content_type = Marcel::MimeType.for media_file.reader, extension: extension
-      return true if ['audio', 'video'].any? { |type| content_type.include?(type) }
 
-      false
+      ['audio', 'video'].any? { |type| content_type.include?(type) }
     end
   end
 end

spec/lib/avalon/ffprobe_spec.rb

@@ -30,7 +30,7 @@
     it 'logs an error if ffprobe is misconfigured' do
       allow(Settings.ffprobe).to receive(:path).and_return('misconfigured/path')
       expect(Rails.logger).to receive(:error)
-      subject
+      subject.json_output
     end
   end