FIX: blank metadata leading to errors (#578)

blank metadata block in RAG was leading to an error, this handles the edge case

app/jobs/regular/digest_rag_upload.rb

@@ -98,6 +98,11 @@ module ::Jobs
           to_chunk = after_metadata
           buffer = buffer.split(metadata_regex, 2).last
           overlap = ""
+        else
+          current_metadata = new_metadata
+          buffer = buffer.split(metadata_regex, 2).last
+          overlap = ""
+          next
         end
 
         chunk, split_char = first_chunk(to_chunk, tokenizer: tokenizer, chunk_tokens: chunk_tokens)

spec/fixtures/rag/doc_with_metadata.txt

@@ -47,3 +47,6 @@ It was a masterpiece of nonsense, a symphony of absurdity that would leave even
 And so, with a flourish of her keyboard and a triumphant grin, Jane unleashed her creation upon the world. The response was immediate and overwhelming. People from all walks of life flocked to converse with Jane’s AI, marveling at its intelligence, its charm, and its uncanny ability to make even the most mundane of topics seem fascinating.
 
 In the end, Jane’s discourse AI became the stuff of legend, a shining example of what can be achieved when brilliance, determination, and a healthy dose of eccentricity come together. And as for Jane herself? Well, let’s just say that she’s already hard at work on her next project: a robot that can make the perfect cup of tea. But that, dear reader, is a story for another day.
+[[metadata blank1]]
+[[metadata blank2]]
+abc

spec/fixtures/rag/parsed_doc_with_metadata.txt

@@ -115,4 +115,8 @@ metadata: Jane's story
 number: 19
 the most mundane of topics seem fascinating.
 
-In the end, Jane’s discourse AI became the stuff of legend, a shining example of what can be achieved when brilliance, determination, and a healthy dose of eccentricity come together. And as for Jane herself? Well, let’s just say that she’s already hard at work on her next project: a robot that can make the perfect cup of tea. But that, dear reader, is a story for another day.
+In the end, Jane’s discourse AI became the stuff of legend, a shining example of what can be achieved when brilliance, determination, and a healthy dose of eccentricity come together. And as for Jane herself? Well, let’s just say that she’s already hard at work on her next project: a robot that can make the perfect cup of tea. But that, dear reader, is a story for another day.
+
+metadata: blank2
+number: 20
+abc

spec/jobs/regular/digest_rag_upload_spec.rb

@@ -57,7 +57,7 @@ RSpec.describe Jobs::DigestRagUpload do
           end
 
         # to rebuild parsed
-        # File.write("/tmp/testing", parsed)
+        #File.write("/tmp/testing", parsed)
 
         expect(parsed).to eq(parsed_document_with_metadata.read)
       end