package.debian: Re-implement debian loader within the package loader mechanism

This introduces the debian package loader.

Contrary to other package loaders, a package can have multiple artifacts (per package version).

In those terms, we had to slightly adapt the swh.loader.package.loader.PackageLoader to demonstrate this. Thus the impacts on pypi, npm, deposit modules as well.

Related #2025 (closed) Related swh-core!91 (closed) Related swh-lister!114 (closed)

Test Plan

tox

---

Migrated from D2135 (view on Phabricator)

swh/loader/package/tests/test_debian.py

@@ -4,15 +4,21 @@
 # See top-level LICENSE file for more information
 
 import copy
+import logging
 import pytest
 
+from os import path
+
 from swh.loader.package.debian import (
     DebianLoader, download_package, dsc_information, uid_to_person,
-    prepare_person
+    prepare_person, get_package_metadata, extract_package
 )
 from swh.loader.package.tests.common import check_snapshot
 
 
+logger = logging.getLogger(__name__)
+
+
 PACKAGE_FILES = {
     'files': {
         'cicero_0.7.2-3.diff.gz': {
@@ -139,6 +145,64 @@ def test_dsc_information_too_many_dsc_entries():
         dsc_information(package_files)
 
 
+def test_get_package_metadata(requests_mock_datadir, datadir, tmp_path):
+    tmp_path = str(tmp_path)  # py3.5 compat.
+    package = PACKAGE_FILES
+
+    logger.debug('package: %s', package)
+
+    # download the packages
+    download_package(package, tmp_path)
+
+    # Retrieve information from package
+    _, dsc_name = dsc_information(package)
+
+    # Extract information from package
+    extracted_path = extract_package(package, tmp_path)
+
+    # Retrieve information on package
+    dsc_path = path.join(path.dirname(extracted_path), dsc_name)
+    actual_package_info = get_package_metadata(
+        package, dsc_path, extracted_path)
+
+    logger.debug('actual_package_info: %s', actual_package_info)
+
+    import datetime
+    from dateutil.tz import tzoffset
+
+    assert actual_package_info == {
+        'changelog': {
+            'date': datetime.datetime(
+                2014, 10, 19, 16, 52, 35, tzinfo=tzoffset(None, 7200)),
+            'history': [
+                ('cicero', '0.7.2-2'),
+                ('cicero', '0.7.2-1'),
+                ('cicero', '0.7-1')
+            ],
+            'person': {
+                'email': 'sthibault@debian.org',
+                'fullname': 'Samuel Thibault <sthibault@debian.org>',
+                'name': 'Samuel Thibault'
+            }
+        },
+        'maintainers': [
+            {
+                'email': 'debian-accessibility@lists.debian.org',
+                'fullname': 'Debian Accessibility Team '
+                '<debian-accessibility@lists.debian.org>',
+                'name': 'Debian Accessibility Team'
+            },
+            {
+                'email': 'sthibault@debian.org',
+                'fullname': 'Samuel Thibault <sthibault@debian.org>',
+                'name': 'Samuel Thibault'
+            }
+        ],
+        'name': 'cicero',
+        'version': '0.7.2-3'
+    }
+
+
 def test_debian_first_visit(
         swh_config, requests_mock_datadir):
     """With no prior visit, load a gnu project ends up with 1 snapshot