Source code for pywebpack.helpers

# -*- coding: utf-8 -*-
#
# This file is part of PyWebpack
# Copyright (C) 2017-2020 CERN.
# Copyright (C) 2020 Cottage Labs LLP.
#
# PyWebpack is free software; you can redistribute it and/or modify
# it under the terms of the Revised BSD License; see LICENSE file for
# more details.

"""Webpack bundle API."""

from __future__ import absolute_import, print_function

from functools import wraps

import pkg_resources
from semver import max_satisfying


def _load_ep(ep):
    mod = ep.load()
    return mod() if callable(mod) else mod


def bundles_from_entry_point(group):
    """Load bundles from entry point group."""
    return (_load_ep(ep) for ep in pkg_resources.iter_entry_points(group))


def cached(f):
    """Decorator to cache result of property."""

    @wraps(f)
    def inner(self):
        name = "_{}".format(f.__name__)
        if getattr(self, name, None) is None:
            setattr(self, name, f(self))
        return getattr(self, name)

    return inner


def check_exit(f):
    """Decorator to ensure that an NPM process exited successfully."""

    @wraps(f)
    def inner(self, *args, **kwargs):
        exit_code = f(self, *args, **kwargs)
        if exit_code != 0:
            raise RuntimeError("Process exited with code {}".format(exit_code))
        return exit_code

    return inner


def merge_deps(deps, bundles_deps):
    """Merge NPM dependencies."""
    keys = ["dependencies", "devDependencies", "peerDependencies"]
    for k in keys:
        deps.setdefault(k, {})
        if k in bundles_deps:
            target_deps = deps[k]
            source_deps = bundles_deps[k]
            for pkg, version in source_deps.items():
                if pkg in target_deps:
                    satisfying = max_satisfying([target_deps[pkg], version], "*", True)
                    target_deps[pkg] = satisfying
                else:
                    target_deps[pkg] = version
    return deps