add method to return s3 key for filename

lib/dor/text_extraction/speech_to_text.rb

@@ -39,6 +39,11 @@ def filenames_to_stt
         stt_files.map(&:filename)
       end
 
+      # return the s3 location for a given filename
+      def s3_location(filename)
+        File.join(job_id, filename)
+      end
+
       # return the job_id for the stt job, defined as the druid-version of the object
       def job_id
         "#{bare_druid}-v#{cocina_object.version}"

lib/robots/dor_repo/speech_to_text/fetch_files.rb

@@ -11,21 +11,15 @@ def initialize
 
         # available from LyberCore::Robot: druid, bare_druid, workflow_service, object_client, cocina_object, logger
         def perform_work
-          sttable_filenames.each do |filename|
-            raise "Unable to fetch #{filename} for #{druid}" unless file_fetcher.write_file_with_retries(filename:, location: aws_provider.bucket.object(File.join(job_id, filename)), max_tries: 3)
+          speech_to_text.filenames_to_stt.each do |filename|
+            raise "Unable to fetch #{filename} for #{druid}" unless file_fetcher.write_file_with_retries(filename:, location: aws_provider.bucket.object(speech_to_text.s3_location(filename)), max_tries: 3)
           end
         end
 
         private
 
-        def sttable_filenames
-          Dor::TextExtraction::SpeechToText.new(cocina_object:).filenames_to_stt
-        end
-
-        # this will be the base of the S3 key for the files sent (to namespace them in the bucket)
-        # it is the same as the job_id when we send the SQS message
-        def job_id
-          @job_id ||= Dor::TextExtraction::SpeechToText.new(cocina_object:).job_id
+        def speech_to_text
+          @speech_to_text ||= Dor::TextExtraction::SpeechToText.new(cocina_object:)
         end
 
         def file_fetcher

spec/lib/dor/text_extraction/speech_to_text_spec.rb

@@ -112,6 +112,15 @@ def build_file(sdr_preserve, shelve, filename)
     end
   end
 
+  describe '#s3_location' do
+    let(:cocina_object) { instance_double(Cocina::Models::DRO, version:, externalIdentifier: druid, dro?: true, type: object_type) }
+    let(:version) { 3 }
+
+    it 'returns the s3 filename key for a given filename' do
+      expect(stt.s3_location('text.xml')).to eq("#{bare_druid}-v#{version}/text.xml")
+    end
+  end
+
   describe '#job_id' do
     let(:cocina_object) { instance_double(Cocina::Models::DRO, version:, externalIdentifier: druid, dro?: true, type: object_type) }
     let(:version) { 3 }

spec/robots/dor_repo/speech_to_text/fetch_files_spec.rb

@@ -34,6 +34,8 @@
     allow(Aws::S3::Client).to receive(:new).and_return(aws_client)
     allow(Aws::S3::Object).to receive(:new).with(bucket_name: Settings.aws.speech_to_text.base_s3_bucket, key: "#{job_id}/file1.mov", client: aws_client).and_return(mov_location)
     allow(Aws::S3::Object).to receive(:new).with(bucket_name: Settings.aws.speech_to_text.base_s3_bucket, key: "#{job_id}/file2.mp3", client: aws_client).and_return(mp3_location)
+    allow(stt).to receive(:s3_location).with('file1.mov').and_return("#{job_id}/file1.mov")
+    allow(stt).to receive(:s3_location).with('file2.mp3').and_return("#{job_id}/file2.mp3")
   end
 
   context 'when fetching files is successful' do