repology: add support for subrepo

Without this, querying latest Fedora packages is impossible because they
reside in 'updates' subrepo but old 'release' versions are returned.
Same thing for openSUSE.

Example config to query Fedora 32 latest packages in updates subrepo:

[somepackage]
source = "repology"
repo = "fedora_32"
subrepo = "updates"

docs/usage.rst

@@ -568,6 +568,11 @@ repology
 repo
   Check the version in this repo. This field is required.
 
+subrepo
+  Check the version in this subrepo. This field is optional.
+  When ommited all subrepos are queried and first entry
+  (not the highest version) is returned.
+
 Check Anitya
 ~~~~~~~~~~~~
 ::

nvchecker_source/repology.py

@@ -8,14 +8,22 @@ API_URL = 'https://repology.org/api/v1/project/{}'
 async def get_version(name, conf, *, cache, **kwargs):
   project = conf.get('repology') or name
   repo = conf.get('repo')
+  subrepo = conf.get('subrepo')
   if not repo:
     raise GetVersionError('repo field is required for repology source')
 
   url = API_URL.format(project)
   data = await cache.get_json(url)
 
-  versions = [pkg['version'] for pkg in data if pkg['repo'] == repo]
-  if not versions:
+  pkgs = [pkg for pkg in data if pkg['repo'] == repo]
+  if not pkgs:
     raise GetVersionError('package is not found', repo=repo)
 
+  if subrepo:
+    pkgs = [pkg for pkg in pkgs if pkg.get('subrepo') == subrepo]
+    if not pkgs:
+        raise GetVersionError('package is not found in subrepo',
+                              repo=repo, subrepo=subrepo)
+
+  versions = [pkg['version'] for pkg in pkgs]
   return versions[0]

tests/test_repology.py

@@ -11,6 +11,23 @@ async def test_repology(get_version):
         "repo": "aur",
   }) == "3.62"
 
+async def test_repology_subrepo(get_version):
+  assert await get_version("asciiquarium", {
+        "source": "repology",
+        "repo": "fedora_32",
+        "subrepo": "release"
+  }) == "1.1"
+
+async def test_repology_bad_subrepo(get_version):
+  try:
+    assert await get_version("asciiquarium", {
+            "source": "repology",
+            "repo": "fedora_32",
+            "subrepo": "badsubrepo"
+    }) is None
+  except RuntimeError as e:
+    assert "package is not found in subrepo" in str(e)
+
 async def test_repology_no_repo(get_version):
   try:
     assert await get_version("ssed", {