cpan: Do not parse intrinsic metadata for getting module author

Parsing perl module metadata files trigger a lot of errors due to badly formatted JSON or YAML and module author info is already provided by the cpan lister as extra loader arguments so remove that no longer needed metadata parsing step.

Related to swh-lister#2833

Depends on !338 (closed)

---

Migrated from D8651 (view on Phabricator)

swh/loader/package/cpan/loader.py

@@ -4,15 +4,12 @@
 # See top-level LICENSE file for more information
 
 from datetime import datetime
-import json
 import logging
-from pathlib import Path
 from typing import Any, Dict, Iterator, List, Optional, Sequence, Tuple
 
 import attr
 import iso8601
 from packaging.version import parse as parse_version
-import yaml
 
 from swh.loader.package.loader import BasePackageInfo, PackageLoader
 from swh.loader.package.utils import EMPTY_AUTHOR, Person, release_name
@@ -38,31 +35,6 @@ class CpanPackageInfo(BasePackageInfo):
     """Author"""
 
 
-def extract_intrinsic_metadata(dir_path: Path) -> Dict[str, Any]:
-    """Extract intrinsic metadata from META.json file at dir_path.
-
-    Most Perl package version have a META.json file at the root of the archive,
-    or a META.yml for older version.
-
-    See https://perldoc.perl.org/CPAN::Meta for META specifications.
-
-    Args:
-        dir_path: A directory on disk where a META.json|.yml can be found
-
-    Returns:
-        A dict mapping from yaml parser
-    """
-    meta_json_path = dir_path / "META.json"
-    meta_yml_path = dir_path / "META.yml"
-    metadata: Dict[str, Any] = {}
-    if meta_json_path.exists():
-        metadata = json.loads(meta_json_path.read_text())
-    elif meta_yml_path.exists():
-        metadata = yaml.safe_load(meta_yml_path.read_text())
-
-    return metadata
-
-
 class CpanLoader(PackageLoader[CpanPackageInfo]):
     visit_type = "cpan"
 
@@ -147,22 +119,6 @@ class CpanLoader(PackageLoader[CpanPackageInfo]):
         self, p_info: CpanPackageInfo, uncompressed_path: str, directory: Sha1Git
     ) -> Optional[Release]:
 
-        # Extract intrinsic metadata from uncompressed_path/META.json|.yml
-        intrinsic_metadata = extract_intrinsic_metadata(
-            Path(uncompressed_path) / f"{p_info.name}-{p_info.version}"
-        )
-
-        # author data from http endpoint are less complete than from META
-        if "author" in intrinsic_metadata:
-            author_data = intrinsic_metadata["author"]
-            if type(author_data) is list:
-                author = author_data[0]
-            else:
-                author = author_data
-            author = Person.from_fullname(author.encode())
-        else:
-            author = p_info.author
-
         message = (
             f"Synthetic release for Perl source package {p_info.name} "
             f"version {p_info.version}\n"
@@ -170,7 +126,7 @@ class CpanLoader(PackageLoader[CpanPackageInfo]):
 
         return Release(
             name=p_info.version.encode(),
-            author=author,
+            author=p_info.author,
             date=TimestampWithTimezone.from_datetime(p_info.last_modified),
             message=message.encode(),
             target_type=ObjectType.DIRECTORY,