hatch_build.py

"""Builds the viewer bundle before hatchling packs a wheel or an sdist.

The HTML report inlines ``viewer/dist/viewer.js``, which esbuild produces from
the TypeScript sources. It is a build output, so git ignores it; this hook
builds it whenever Node.js is available and fails clearly when it is not,
unless the bundle is already there (as in a wheel built from an sdist).
"""

from __future__ import annotations

import shutil
import subprocess
from pathlib import Path
from typing import Any

from hatchling.builders.config import BuilderConfig
from hatchling.builders.hooks.plugin.interface import BuildHookInterface

VIEWER_BUNDLE = "src/codemap/rendering/viewer/dist/viewer.js"


class ViewerBuildHook(BuildHookInterface[BuilderConfig]):
    PLUGIN_NAME = "custom"

    def initialize(self, version: str, build_data: dict[str, Any]) -> None:
        root = Path(self.root)
        npm = shutil.which("npm")

        if npm and (root / "package.json").is_file():
            self._build(root, npm)

        if not (root / VIEWER_BUNDLE).is_file():
            raise RuntimeError(
                f"{VIEWER_BUNDLE} is missing: install Node.js 22.6 or newer, "
                "then run `npm ci && npm run build`"
            )

    def _build(self, root: Path, npm: str) -> None:
        # npm ci wipes node_modules, so it runs only when the dependencies are not installed yet.
        if not (root / "node_modules").is_dir():
            subprocess.run([npm, "ci"], cwd=root, check=True)

        subprocess.run([npm, "run", "build"], cwd=root, check=True)