FIX: Don't check for #blank? when manipulating chunks (#1428)

Author: romanrizzi

lib/completions/json_streaming_tracker.rb

@@ -74,7 +74,7 @@ def <<(raw_json)
       private
 
       def try_escape_and_parse(raw_json)
-        if raw_json.blank? || !raw_json.is_a?(String)
+        if !raw_json.is_a?(String)
           @broken = true
           return
         end

spec/lib/completions/endpoints/gemini_spec.rb

@@ -544,7 +544,9 @@ def tool_response
 
         data: {"candidates": [{"content": {"parts": [{"text": "Hello!"}],"role": "model"},"finishReason": "STOP"}],"usageMetadata": {"promptTokenCount": 399,"candidatesTokenCount": 191,"totalTokenCount": 590},"modelVersion": "gemini-1.5-pro-002"}
 
-        data: {"candidates": [{"content": {"parts": [{"text": "\\n there"}],"role": "model"},"finishReason": "STOP"}],"usageMetadata": {"promptTokenCount": 399,"candidatesTokenCount": 191,"totalTokenCount": 590},"modelVersion": "gemini-1.5-pro-002"}
+        data: {"candidates": [{"content": {"parts": [{"text": "\\n "}],"role": "model"},"finishReason": "STOP"}],"usageMetadata": {"promptTokenCount": 399,"candidatesTokenCount": 191,"totalTokenCount": 590},"modelVersion": "gemini-1.5-pro-002"}
+
+        data: {"candidates": [{"content": {"parts": [{"text": "there"}],"role": "model"},"finishReason": "STOP"}],"usageMetadata": {"promptTokenCount": 399,"candidatesTokenCount": 191,"totalTokenCount": 590},"modelVersion": "gemini-1.5-pro-002"}
 
         data: {"candidates": [{"content": {"parts": [{"text": "\\","}],"role": "model"},"finishReason": "STOP"}],"usageMetadata": {"promptTokenCount": 399,"candidatesTokenCount": 191,"totalTokenCount": 590},"modelVersion": "gemini-1.5-pro-002"}
 

spec/lib/completions/structured_output_spec.rb

@@ -112,6 +112,14 @@
         ["Hello! I am a chunk", "There"],
       )
     end
+
+    it "handles empty newline chunks" do
+      chunks = [+"{\"", +"message", +"\":\"", +"Hello!", +"\n", +"\"", +"}"]
+
+      chunks.each { |c| structured_output << c }
+
+      expect(structured_output.read_buffered_property(:message)).to eq("Hello!\n")
+    end
   end
 
   describe "dealing with non-JSON responses" do