Make debian lister constructors compatible with credentials

In effect, it just allows to add credentials to cgit, cran and pypi listers.

This fixes instances of error [1]

[1] https://sentry.softwareheritage.org/share/issue/a5fb50f8e43e4b328c4917771576c6b0/

Related to T2998

swh/lister/debian/lister.py

@@ -11,7 +11,7 @@ import gzip
 from itertools import product
 import logging
 import lzma
-from typing import Any, Callable, Dict, Iterator, List, Set, Tuple
+from typing import Any, Callable, Dict, Iterator, List, Optional, Set, Tuple
 from urllib.parse import urljoin
 
 from debian.deb822 import Sources
@@ -21,7 +21,7 @@ from swh.scheduler.interface import SchedulerInterface
 from swh.scheduler.model import ListedOrigin
 
 from .. import USER_AGENT
-from ..pattern import Lister
+from ..pattern import CredentialsType, Lister
 
 logger = logging.getLogger(__name__)
 
@@ -76,9 +76,13 @@ class DebianLister(Lister[DebianListerState, DebianPageType]):
         mirror_url: str = "http://deb.debian.org/debian/",
         suites: List[Suite] = ["stretch", "buster", "bullseye"],
         components: List[Component] = ["main", "contrib", "non-free"],
+        credentials: Optional[CredentialsType] = None,
     ):
         super().__init__(
-            scheduler=scheduler, url=mirror_url, instance=distribution,
+            scheduler=scheduler,
+            url=mirror_url,
+            instance=distribution,
+            credentials=credentials,
         )
 
         # to ensure urljoin will produce valid Sources URL

swh/lister/debian/tests/test_lister.py

@@ -199,3 +199,34 @@ def test_lister_debian_updated_packages(
             assert stats.origins == 0
         else:
             assert stats.origins != 0
+
+
+@pytest.mark.parametrize(
+    "credentials, expected_credentials",
+    [
+        (None, []),
+        ({"key": "value"}, []),
+        (
+            {"debian": {"Debian": [{"username": "user", "password": "pass"}]}},
+            [{"username": "user", "password": "pass"}],
+        ),
+    ],
+)
+def test_lister_debian_instantiation_with_credentials(
+    credentials, expected_credentials, swh_scheduler
+):
+    lister = DebianLister(swh_scheduler, credentials=credentials)
+
+    # Credentials are allowed in constructor
+    assert lister.credentials == expected_credentials
+
+
+def test_lister_debian_from_configfile(swh_scheduler_config, mocker):
+    load_from_envvar = mocker.patch("swh.lister.pattern.load_from_envvar")
+    load_from_envvar.return_value = {
+        "scheduler": {"cls": "local", **swh_scheduler_config},
+        "credentials": {},
+    }
+    lister = DebianLister.from_configfile()
+    assert lister.scheduler is not None
+    assert lister.credentials is not None