fix: resolve Python 3.9 compatibility in remaining integration test files

- Fix union type syntax in test_smoke.py
- Fix union type syntax in test_watermark_image_file_integration.py
- Fix union type syntax in test_live_api.py
- Add proper typing imports to all integration test files
- Replace isinstance with tuple syntax for Python 3.9 compatibility

This completes Python 3.9 compatibility across the entire codebase.
All tests now collect and import correctly.

Author: jdrhyne

tests/integration/test_live_api.py

@@ -5,29 +5,31 @@
 
 from __future__ import annotations
 
+from typing import Optional, Union
+
 import pytest
 
 from nutrient_dws import NutrientClient
 
 try:
     from . import integration_config  # type: ignore[attr-defined]
 
-    API_KEY: str | None = integration_config.API_KEY
-    BASE_URL: str | None = getattr(integration_config, "BASE_URL", None)
+    API_KEY: Optional[str] = integration_config.API_KEY
+    BASE_URL: Optional[str] = getattr(integration_config, "BASE_URL", None)
     TIMEOUT: int = getattr(integration_config, "TIMEOUT", 60)
 except ImportError:
     API_KEY = None
     BASE_URL = None
     TIMEOUT = 60
 
 
-def assert_is_pdf(file_path_or_bytes: str | bytes) -> None:
+def assert_is_pdf(file_path_or_bytes: Union[str, bytes]) -> None:
     """Assert that a file or bytes is a valid PDF.
 
     Args:
         file_path_or_bytes: Path to file or bytes content to check.
     """
-    if isinstance(file_path_or_bytes, str | bytes):
+    if isinstance(file_path_or_bytes, (str, bytes)):
         if isinstance(file_path_or_bytes, str):
             with open(file_path_or_bytes, "rb") as f:
                 content = f.read(8)

tests/integration/test_smoke.py

@@ -1,11 +1,13 @@
 """Basic smoke test to validate integration test setup."""
 
+from typing import Optional
+
 import pytest
 
 from nutrient_dws import NutrientClient
 
 # Type annotation for mypy
-API_KEY: str | None = None
+API_KEY: Optional[str] = None
 
 try:
     from . import integration_config  # type: ignore[attr-defined]

tests/integration/test_watermark_image_file_integration.py

@@ -2,6 +2,7 @@
 
 import os
 from pathlib import Path
+from typing import Optional, Union
 
 import pytest
 
@@ -10,16 +11,16 @@
 try:
     from . import integration_config  # type: ignore[attr-defined]
 
-    API_KEY: str | None = integration_config.API_KEY
-    BASE_URL: str | None = getattr(integration_config, "BASE_URL", None)
+    API_KEY: Optional[str] = integration_config.API_KEY
+    BASE_URL: Optional[str] = getattr(integration_config, "BASE_URL", None)
     TIMEOUT: int = getattr(integration_config, "TIMEOUT", 60)
 except ImportError:
     API_KEY = None
     BASE_URL = None
     TIMEOUT = 60
 
 
-def assert_is_pdf(file_path_or_bytes: str | bytes) -> None:
+def assert_is_pdf(file_path_or_bytes: Union[str, bytes]) -> None:
     """Assert that a file or bytes is a valid PDF."""
     if isinstance(file_path_or_bytes, str):
         with open(file_path_or_bytes, "rb") as f: