fix(core): clean up orphaned temp files on atomic write failure (#6068)

* fix(core): clean up orphaned temp files on atomic write failure

* fixed reviewer suggestion

* removed whitespace

core/atomic_io.py

@@ -30,11 +30,20 @@ def atomic_write_json(path: str, data: Any, *, indent: Optional[int] = None) ->
     """
     os.makedirs(os.path.dirname(path) or ".", exist_ok=True)
     tmp = f"{path}.tmp.{uuid.uuid4().hex}"
-    with open(tmp, "w", encoding="utf-8") as f:
-        json.dump(data, f, indent=indent)
-        f.flush()
-        os.fsync(f.fileno())
-    os.replace(tmp, path)
+
+    try:
+        with open(tmp, "w", encoding="utf-8") as f:
+            json.dump(data, f, indent=indent)
+            f.flush()
+            os.fsync(f.fileno())
+        os.replace(tmp, path)
+    finally:
+        # Directly unlink to avoid a check-then-act race condition.
+        # Swallows FileNotFoundError (on success path) and other cleanup OSErrors.
+        try:
+            os.unlink(tmp)
+        except OSError:
+            pass
 
 
 def atomic_write_text(path: str, text: str) -> None:
@@ -42,8 +51,17 @@ def atomic_write_text(path: str, text: str) -> None:
         raise TypeError("atomic_write_text expects a string")
     os.makedirs(os.path.dirname(path) or ".", exist_ok=True)
     tmp = f"{path}.tmp.{uuid.uuid4().hex}"
-    with open(tmp, "w", encoding="utf-8") as f:
-        f.write(text)
-        f.flush()
-        os.fsync(f.fileno())
-    os.replace(tmp, path)
+
+    try:
+        with open(tmp, "w", encoding="utf-8") as f:
+            f.write(text)
+            f.flush()
+            os.fsync(f.fileno())
+        os.replace(tmp, path)
+    finally:
+        # Directly unlink to avoid a check-then-act race condition.
+        # Swallows FileNotFoundError (on success path) and other cleanup OSErrors.
+        try:
+            os.unlink(tmp)
+        except OSError:
+            pass