From 1a007a54a6d9750fa9162b318e146dddde53d37c Mon Sep 17 00:00:00 2001
From: Kayvan Zahiri <123409429+Kayvan-Zahiri@users.noreply.github.com>
Date: Tue, 20 Oct 2026 21:28:38 -0700
Subject: [PATCH] fix(python): preserve final JSON Lines records without a
 trailing newline

---
 .changesets/1792556768-64f74b9f.yaml          | 10 +++
 .../{{getSourcePath}}/utils/jsonl.py.stmpl    |  4 +-
 .../test_jsonl_streaming_additional.py        | 61 +++++++++++++++++++
 3 files changed, 73 insertions(+), 2 deletions(-)
 create mode 100644 .changesets/1792556768-64f74b9f.yaml

diff --git a/.changesets/1792556768-64f74b9f.yaml b/.changesets/1792556768-64f74b9f.yaml
new file mode 100644
index 000000000..6d3737c05
--- /dev/null
+++ b/.changesets/1792556768-64f74b9f.yaml
@@ -0,0 +1,10 @@
+id: 1792556768-64f74b9f
+features:
+    - jsonlResponses
+targets:
+    - pythonv2
+type: fix
+bump: patch
+description: preserve final JSON Lines records without a trailing newline
+author: Kayvan-Zahiri
+date: "2026-10-20"
diff --git a/templates/templates/pythonv2/auxiliary/{{getSourcePath}}/utils/jsonl.py.stmpl b/templates/templates/pythonv2/auxiliary/{{getSourcePath}}/utils/jsonl.py.stmpl
index 438aa25a5..37bca79cf 100644
--- a/templates/templates/pythonv2/auxiliary/{{getSourcePath}}/utils/jsonl.py.stmpl
+++ b/templates/templates/pythonv2/auxiliary/{{getSourcePath}}/utils/jsonl.py.stmpl
@@ -110,7 +110,7 @@ async def stream_jsonl_events_async(
             buffer = buffer[position:]
             position = 0
 
-    if position != 0:
+    if buffer.strip():
         event = decoder(buffer.decode())
         yield event
 
@@ -145,7 +145,7 @@ def stream_jsonl_events(
             buffer = buffer[position:]
             position = 0
 
-    if position != 0:
+    if buffer.strip():
         event = decoder(buffer.decode())
         yield event
 
diff --git a/templates/templates/pythonv2/tests/primary/test_jsonl_streaming_additional.py b/templates/templates/pythonv2/tests/primary/test_jsonl_streaming_additional.py
index 09c3f28b9..4ae6f4888 100644
--- a/templates/templates/pythonv2/tests/primary/test_jsonl_streaming_additional.py
+++ b/templates/templates/pythonv2/tests/primary/test_jsonl_streaming_additional.py
@@ -1,3 +1,5 @@
+import json
+import httpx
 import time
 import pytest
 from openapi import SDK
@@ -5,6 +7,7 @@
 from openapi.models.shared import *
 from openapi.utils import *
 from openapi.utils import jsonl
+from openapi.utils.jsonl import JsonLStream, JsonLStreamAsync
 
 from .common_helpers import *
 from .test_helpers import *
@@ -164,3 +167,61 @@ async def create_generator():
         nb_chunks += 1
 
     assert nb_chunks == 2, "The generator should yield exactly 2 chunks"
+
+
+CASES = [
+    (b"", []),
+    (b'{"name":"one"}\n', [{"name": "one"}]),
+    (b'{"name":"one"}', [{"name": "one"}]),
+    (b'{"name":"one"}\n{"name":"two"}', [{"name": "one"}, {"name": "two"}]),
+    (b'{"name":"one"}\r\n{"name":"two"}', [{"name": "one"}, {"name": "two"}]),
+    (b'{"name":"one"}\n \t\r\n', [{"name": "one"}]),
+    ('{"name":"café"}'.encode(), [{"name": "café"}]),
+    (b'{"name":"one"}\r\n{"name":"two"}\r\n', [{"name": "one"}, {"name": "two"}]),
+]
+
+
+class ChunkStream(httpx.SyncByteStream, httpx.AsyncByteStream):
+    def __init__(self, payload, chunk_size):
+        self.chunks = [payload] if chunk_size is None else [
+            payload[i:i + chunk_size] for i in range(0, len(payload), chunk_size)
+        ]
+
+    def __iter__(self):
+        yield from self.chunks
+
+    async def __aiter__(self):
+        for chunk in self.chunks:
+            yield chunk
+
+
+@pytest.mark.parametrize("payload, expected", CASES)
+@pytest.mark.parametrize("chunk_size", [None, 1, 5])
+def test_jsonl_final_record(payload, expected, chunk_size):
+    response = httpx.Response(200, stream=ChunkStream(payload, chunk_size))
+    with JsonLStream(response, json.loads) as events:
+        assert list(events) == expected
+    assert response.is_closed
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize("payload, expected", CASES)
+@pytest.mark.parametrize("chunk_size", [None, 1, 5])
+async def test_jsonl_final_record_async(payload, expected, chunk_size):
+    response = httpx.Response(200, stream=ChunkStream(payload, chunk_size))
+    async with JsonLStreamAsync(response, json.loads) as events:
+        assert [event async for event in events] == expected
+    assert response.is_closed
+
+
+def test_jsonl_invalid_final_record():
+    response = httpx.Response(200, stream=ChunkStream(b'{"name":', 1))
+    with pytest.raises(json.JSONDecodeError):
+        list(JsonLStream(response, json.loads))
+
+
+@pytest.mark.asyncio
+async def test_jsonl_invalid_final_record_async():
+    response = httpx.Response(200, stream=ChunkStream(b'{"name":', 1))
+    with pytest.raises(json.JSONDecodeError):
+        [event async for event in JsonLStreamAsync(response, json.loads)]