wip use type aliases, tighten up typing

Author: datalogics-kam

pyproject.toml

@@ -60,6 +60,8 @@ files = "src"
 [tool.pyright]
 venvPath = "."
 venv = ".venv"
+pythonVersion = "3.9"
+typeCheckingMode = "strict"
 
 [tool.pytest.ini_options]
 minversion = "7.4"

src/pdfrest/client.py

@@ -4,11 +4,12 @@
 
 import os
 from collections.abc import Mapping
-from typing import Any, Generic, Literal, Optional, TypedDict, TypeVar, cast
+from typing import Any, Generic, Literal, TypedDict, TypeVar, Union, cast
 
 import httpx
 from httpx import URL
 from pydantic import BaseModel, ConfigDict, Field, ValidationError, field_validator
+from typing_extensions import TypeAlias
 
 from .exceptions import (
     PdfRestApiError,
@@ -23,9 +24,17 @@
 API_KEY_ENV_VAR = "PDFREST_API_KEY"
 DEFAULT_TIMEOUT_SECONDS = 10.0
 
-HttpMethod = Literal["GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS", "HEAD"]
-QueryParamValue = str | int | float | bool | None
-TimeoutTypes = float | httpx.Timeout | None
+HttpMethod: TypeAlias = Literal[
+    "GET",
+    "POST",
+    "PUT",
+    "PATCH",
+    "DELETE",
+    "OPTIONS",
+    "HEAD",
+]
+QueryParamValue: TypeAlias = Union[str, int, float, bool, None]
+TimeoutTypes: TypeAlias = Union[float, httpx.Timeout, None]
 
 
 ClientType = TypeVar("ClientType", httpx.Client, httpx.AsyncClient)
@@ -154,7 +163,7 @@ def __init__(
         timeout: TimeoutTypes = DEFAULT_TIMEOUT_SECONDS,
         headers: Mapping[str, str] | None = None,
     ) -> None:
-        resolved_api_key = (api_key or os.getenv(API_KEY_ENV_VAR, "")).strip()
+        resolved_api_key = (api_key or os.getenv(API_KEY_ENV_VAR) or "").strip()
         if not resolved_api_key:
             msg = "API key was not provided and the PDFREST_API_KEY environment variable is not set."
             raise PdfRestConfigurationError(msg)
@@ -233,19 +242,28 @@ def _prepare_request(
             raise PdfRestConfigurationError(str(exc)) from exc
         return request
 
+    def _message_from_payload(self, payload: Any) -> str:
+        if isinstance(payload, str):
+            return payload
+        if isinstance(payload, Mapping):
+            m = cast(Mapping[str, object], payload)
+            candidate = m.get("error", m.get("message"))
+            if isinstance(candidate, str):
+                return candidate
+        return "pdfRest returned an error"
+
     def _handle_response(self, response: httpx.Response) -> Any:
         if response.is_success:
             return self._decode_json(response)
         error_payload: Any = None
-        message: str | None = None
         try:
             error_payload = response.json()
-            if isinstance(error_payload, Mapping):
-                message = cast(Optional[str], error_payload.get("message"))
         except ValueError:
             error_payload = response.text
         raise PdfRestApiError(
-            response.status_code, message=message, response_content=error_payload
+            response.status_code,
+            message=self._message_from_payload(error_payload),
+            response_content=error_payload,
         )
 
     def _decode_json(self, response: httpx.Response) -> Any: