feat(core): CPA_* errors (#24)

packages/create-python-app-core/src/create_python_app_core/__init__.py

@@ -10,9 +10,25 @@
  create_python_app,
  print_env_info,
 )
+from create_python_app_core.errors import (
+ NON_EMPTY_DIR_ERROR_CODE,
+ ConfigParseError,
+ CpaError,
+ ManifestLoadError,
+ NonEmptyTargetDirectoryError,
+ PackageManagerFallbackError,
+ ScaffoldAbortedError,
+)
 
 __all__ = [
  "__version__",
+ "CpaError",
+ "ConfigParseError",
+ "ManifestLoadError",
+ "PackageManagerFallbackError",
+ "ScaffoldAbortedError",
+ "NonEmptyTargetDirectoryError",
+ "NON_EMPTY_DIR_ERROR_CODE",
  "CPA_USER_AGENT",
  "check_for_latest_version",
  "check_python_version",

packages/create-python-app-core/src/create_python_app_core/errors.py

@@ -0,0 +1,37 @@
+"""Typed CPA errors (mirrors create-node-app-core/errors.ts)."""
+
+from __future__ import annotations
+
+
+class CpaError(Exception):
+ """Base error with a stable machine-readable code."""
+
+ code: str = "CPA_ERROR"
+
+ def __init__(self, message: str, *, code: str | None = None) -> None:
+ super().__init__(message)
+ if code is not None:
+ self.code = code
+
+
+class ConfigParseError(CpaError):
+ code = "CPA_CONFIG_PARSE"
+
+
+class ManifestLoadError(CpaError):
+ code = "CPA_MANIFEST_LOAD"
+
+
+class PackageManagerFallbackError(CpaError):
+ code = "CPA_PM_FALLBACK"
+
+
+class ScaffoldAbortedError(CpaError):
+ code = "CPA_ABORTED"
+
+
+class NonEmptyTargetDirectoryError(CpaError):
+ code = "CPA_NON_EMPTY_TARGET_DIR"
+
+
+NON_EMPTY_DIR_ERROR_CODE = NonEmptyTargetDirectoryError.code

packages/create-python-app-core/tests/test_errors.py

@@ -0,0 +1,12 @@
+from create_python_app_core import (
+ NON_EMPTY_DIR_ERROR_CODE,
+ ConfigParseError,
+ CpaError,
+ NonEmptyTargetDirectoryError,
+)
+
+
+def test_error_codes_use_cpa_prefix() -> None:
+ assert ConfigParseError("x").code.startswith("CPA_")
+ assert NonEmptyTargetDirectoryError("x").code == NON_EMPTY_DIR_ERROR_CODE
+ assert isinstance(ConfigParseError("x"), CpaError)