Method parse

src/packagedcode/build.py:141–214

(cls, location, package_only=False)

    @classmethod
    def parse(cls, location, package_only=False):
        # Thanks to Starlark being a Python dialect, we can use `ast` to parse it
        with open(location, 'rb') as f:
            tree = ast.parse(f.read())

        build_rules = defaultdict(list)
        for statement in tree.body:
            # We only care about function calls or assignments to functions whose
            # names ends with one of the strings in `rule_types`
            if (
                isinstance(statement, ast.Expr)
                or isinstance(statement, ast.Call)
                or isinstance(statement, ast.Assign)
                and isinstance(statement.value, ast.Call)
                and isinstance(statement.value.func, ast.Name)
            ):
                rule_name = statement.value.func.id
                # Ensure that we are only creating packages from the proper
                # build rules
                if not check_rule_name_ending(rule_name):
                    continue
                # Process the rule arguments
                args = {}
                for kw in statement.value.keywords:
                    arg_name = kw.arg
                    if isinstance(kw.value, ast.Constant) and isinstance(kw.value.value, str):
                        args[arg_name] = kw.value.value

                    if isinstance(kw.value, ast.List):
                        # We collect the elements of a list if the element is
                        # not a function call
                        args[arg_name] = [
                            elt.value for elt in kw.value.elts
                            if not isinstance(elt, ast.Call)
                        ]
                if args:
                    build_rules[rule_name].append(args)

        if build_rules:
            for rule_name, rule_instances_args in build_rules.items():
                for args in rule_instances_args:
                    name = args.get('name')

                    # FIXME: we could still return partial package data
                    if not name:
                        continue

                    license_files = args.get('licenses')

                    if TRACE:
                        logger_debug(f"build: parse: license_files: {license_files}")

                    package_data = dict(
                        datasource_id=cls.datasource_id,
                        type=cls.default_package_type,
                        name=name,
                        extracted_license_statement=license_files,
                    )