feat(core): cpa.config.json loader and schema docs (#28)

docs/cpa-config-schema.md

@@ -0,0 +1,19 @@
+# `cpa.config.json` schema
+
+Mirrors `cna.config.json` from Create-Node-App with Python-oriented fields.
+
+```json
+{
+ "name": "fastapi-starter",
+ "customOptions": [
+ {
+ "key": "projectName",
+ "type": "string",
+ "message": "Project name",
+ "default": "my-app"
+ }
+ ]
+}
+```
+
+Parse errors raise `CPA_CONFIG_PARSE`.

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

@@ -50,6 +50,10 @@
  "merge_layers",
  "load_layer",
  "get_template_dir_path",
+ "CpaConfig",
+ "CpaCustomOption",
+ "load_cpa_config",
+ "assert_directory_is_empty",
  "CPA_USER_AGENT",
  "check_for_latest_version",
  "check_python_version",

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

@@ -0,0 +1,63 @@
+"""cpa.config.json schema and loaders."""
+
+from __future__ import annotations
+
+import json
+from dataclasses import dataclass, field
+from pathlib import Path
+from typing import Any
+
+from create_python_app_core.errors import (
+ ConfigParseError,
+ NonEmptyTargetDirectoryError,
+)
+
+
+@dataclass
+class CpaCustomOption:
+ key: str
+ type: str = "string"
+ message: str = ""
+ default: Any = None
+
+
+@dataclass
+class CpaConfig:
+ name: str | None = None
+ custom_options: list[CpaCustomOption] = field(default_factory=list)
+ raw: dict[str, Any] = field(default_factory=dict)
+
+
+def load_cpa_config(path: Path) -> CpaConfig:
+ if not path.is_file():
+ return CpaConfig()
+ try:
+ data = json.loads(path.read_text(encoding="utf-8"))
+ except json.JSONDecodeError as exc:
+ raise ConfigParseError(f"Invalid cpa.config.json: {exc}") from exc
+ if not isinstance(data, dict):
+ raise ConfigParseError("cpa.config.json must be a JSON object")
+ options: list[CpaCustomOption] = []
+ for item in data.get("customOptions") or data.get("custom_options") or []:
+ if not isinstance(item, dict) or "key" not in item:
+ raise ConfigParseError("custom option missing key")
+ options.append(
+ CpaCustomOption(
+ key=str(item["key"]),
+ type=str(item.get("type", "string")),
+ message=str(item.get("message", "")),
+ default=item.get("default"),
+ )
+ )
+ return CpaConfig(
+ name=data.get("name"),
+ custom_options=options,
+ raw=data,
+ )
+
+
+def assert_directory_is_empty(path: Path, *, force: bool = False) -> None:
+ if force:
+ return
+ if path.exists() and any(path.iterdir()):
+ raise NonEmptyTargetDirectoryError(f"Target directory is not empty: {path}")

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

@@ -0,0 +1,35 @@
+import json
+from pathlib import Path
+
+import pytest
+from create_python_app_core.config import assert_directory_is_empty, load_cpa_config
+from create_python_app_core.errors import ConfigParseError, NonEmptyTargetDirectoryError
+
+
+def test_load_config(tmp_path: Path) -> None:
+ path = tmp_path / "cpa.config.json"
+ path.write_text(
+ json.dumps(
+ {
+ "name": "demo",
+ "customOptions": [{"key": "projectName", "default": "x"}],
+ }
+ )
+ )
+ cfg = load_cpa_config(path)
+ assert cfg.name == "demo"
+ assert cfg.custom_options[0].key == "projectName"
+
+
+def test_bad_json(tmp_path: Path) -> None:
+ path = tmp_path / "cpa.config.json"
+ path.write_text("{")
+ with pytest.raises(ConfigParseError):
+ load_cpa_config(path)
+
+
+def test_non_empty(tmp_path: Path) -> None:
+ (tmp_path / "f").write_text("x")
+ with pytest.raises(NonEmptyTargetDirectoryError):
+ assert_directory_is_empty(tmp_path)
+ assert_directory_is_empty(tmp_path, force=True)