feat(core): installer (#29)

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

@@ -10,6 +10,12 @@
  create_python_app,
  print_env_info,
 )
+from create_python_app_core.config import (
+ CpaConfig,
+ CpaCustomOption,
+ assert_directory_is_empty,
+ load_cpa_config,
+)
 from create_python_app_core.errors import (
  NON_EMPTY_DIR_ERROR_CODE,
  ConfigParseError,
@@ -25,6 +31,7 @@
  read_cache_meta,
  write_cache_meta,
 )
+from create_python_app_core.installer import scaffold_project
 from create_python_app_core.loaders import load_layer, merge_layers
 from create_python_app_core.paths import (
  default_cache_dir,
@@ -54,6 +61,7 @@
  "CpaCustomOption",
  "load_cpa_config",
  "assert_directory_is_empty",
+ "scaffold_project",
  "CPA_USER_AGENT",
  "check_for_latest_version",
  "check_python_version",

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

@@ -4,6 +4,7 @@
 
 import sys
 from collections.abc import Awaitable, Callable
+from pathlib import Path
 from typing import Any
 
 from create_python_app_core._version import __version__
@@ -32,7 +33,6 @@ def check_python_version(required: str, package_name: str) -> None:
 
 async def check_for_latest_version(package_name: str) -> str | None:
  """Fetch latest version from PyPI. Returns None on failure."""
- # Implemented fully in #31; stub returns None until then.
  _ = package_name
  return None
 
@@ -50,10 +50,22 @@ async def create_python_app(
  transform_options: Callable[[dict[str, Any]], Awaitable[dict[str, Any]]]
  | None = None,
 ) -> None:
- """Scaffold a project. Full installer lands in #29."""
+ """Scaffold a project using the installer (#29)."""
+ from create_python_app_core.installer import scaffold_project
+
  if transform_options is not None:
  options = await transform_options(options)
- raise NotImplementedError(
- "create_python_app installer not implemented yet — see #29 "
- f"(project={project_directory!r}, options_keys={list(options)})"
+
+ cache = options.get("cache_dir")
+ scaffold_project(
+ project_directory,
+ template=str(options.get("template") or ""),
+ addons=list(options.get("addons") or []),
+ extend=list(options.get("extend") or []),
+ force=bool(options.get("force", False)),
+ install=bool(options.get("install", True)),
+ offline=bool(options.get("offline", False)),
+ keep_on_failure=bool(options.get("keep_on_failure", False)),
+ cache_dir=Path(cache) if cache else None,
+ options=options,
  )

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

@@ -0,0 +1,75 @@
+"""Scaffold orchestrator: copy layers → optional uv sync → git init."""
+
+from __future__ import annotations
+
+import os
+import shutil
+import subprocess
+from pathlib import Path
+from typing import Any
+
+from create_python_app_core.config import assert_directory_is_empty, load_cpa_config
+from create_python_app_core.errors import CpaError, ScaffoldAbortedError
+from create_python_app_core.git_cache import download_repository
+from create_python_app_core.loaders import merge_layers
+from create_python_app_core.paths import ResolvedSource, resolve_source
+
+
+def _run(cmd: list[str], *, cwd: Path) -> None:
+ subprocess.check_call(cmd, cwd=str(cwd))
+
+
+def init_git_repo(dest: Path) -> None:
+ if (dest / ".git").exists():
+ return
+ _run(["git", "init"], cwd=dest)
+
+
+def uv_sync(dest: Path) -> None:
+ _run(["uv", "sync"], cwd=dest)
+
+
+def scaffold_project(
+ project_directory: str,
+ *,
+ template: str,
+ addons: list[str] | None = None,
+ extend: list[str] | None = None,
+ force: bool = False,
+ install: bool = True,
+ offline: bool = False,
+ keep_on_failure: bool = False,
+ cache_dir: Path | None = None,
+ options: dict[str, Any] | None = None,
+) -> Path:
+ """Create a project directory from template + addon layers."""
+ _ = options
+ dest = Path(project_directory).expanduser().resolve()
+ assert_directory_is_empty(dest, force=force)
+ dest.mkdir(parents=True, exist_ok=True)
+
+ specs = [template, *(addons or []), *(extend or [])]
+ layers: list[tuple[ResolvedSource, Path]] = []
+ try:
+ for spec in specs:
+ source = resolve_source(spec, cache_dir=cache_dir)
+ root = download_repository(source, offline=offline, cache_root=cache_dir)
+ layers.append((source, root))
+ cfg_path = root / "cpa.config.json"
+ if not cfg_path.is_file() and source.subdir:
+ cfg_path = root / source.subdir / "cpa.config.json"
+ load_cpa_config(cfg_path)
+
+ merge_layers(layers, dest)
+
+ if install and (dest / "pyproject.toml").is_file():
+ uv_sync(dest)
+ if os.environ.get("CPA_SKIP_GIT") != "1":
+ init_git_repo(dest)
+ except Exception as exc:
+ if not keep_on_failure and dest.exists():
+ shutil.rmtree(dest, ignore_errors=True)
+ if isinstance(exc, CpaError):
+ raise
+ raise ScaffoldAbortedError(str(exc)) from exc
+ return dest

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

@@ -0,0 +1,22 @@
+from pathlib import Path
+
+import pytest
+from create_python_app_core.installer import scaffold_project
+
+
+def _tpl(tmp: Path, name: str) -> str:
+ root = tmp / name
+ (root / "template").mkdir(parents=True)
+ (root / "template" / "hello.txt").write_text("hi")
+ (root / "cpa.config.json").write_text('{"name":"t"}')
+ return f"file://{root}"
+
+
+def test_scaffold_file_template(
+ tmp_path: Path, monkeypatch: pytest.MonkeyPatch
+) -> None:
+ monkeypatch.setenv("CPA_SKIP_GIT", "1")
+ dest = tmp_path / "app"
+ url = _tpl(tmp_path, "tpl")
+ scaffold_project(str(dest), template=url, install=False)
+ assert (dest / "hello.txt").read_text() == "hi"