Remove improvers for alpine and nvd

Add tests for default improver using alpine and nvd advisories.

Signed-off-by: Tushar Goel <tushar.goel.dav@gmail.com>

Author: TG1999

vulnerabilities/importers/alpine_linux.py

@@ -245,21 +245,3 @@ def load_advisories(
                 affected_packages=affected_packages,
                 aliases=aliases,
             )
-
-
-class AlpineBasicImprover(Improver):
-    @property
-    def interesting_advisories(self) -> QuerySet:
-        return Advisory.objects.filter(created_by=AlpineImporter.qualified_name)
-
-    def get_inferences(self, advisory_data: AdvisoryData) -> Iterable[Inference]:
-        """
-        Generate and return Inferences for the given advisory data
-        """
-        for affected_package in advisory_data.affected_packages:
-            fixed_purl = affected_package.get_fixed_purl()
-            yield Inference.from_advisory_data(
-                advisory_data,
-                confidence=MAX_CONFIDENCE,
-                fixed_purl=fixed_purl,
-            )

vulnerabilities/importers/nvd.py

@@ -195,14 +195,3 @@ def extract_severity_scores(cve_item):
             system=SCORING_SYSTEMS["cvssv2_vector"],
             value=str(cvss_v2.get("vectorString") or ""),
         )
-
-
-class NVDBasicImprover(Improver):
-    @property
-    def interesting_advisories(self) -> QuerySet:
-        return Advisory.objects.filter(created_by=NVDImporter.qualified_name)
-
-    def get_inferences(self, advisory_data: AdvisoryData) -> Iterable[Inference]:
-        yield Inference.from_advisory_data(
-            advisory_data=advisory_data, confidence=100, fixed_purl=None
-        )

vulnerabilities/improvers/__init__.py

@@ -4,9 +4,7 @@
 IMPROVERS_REGISTRY = [
     default.DefaultImprover,
     importers.nginx.NginxBasicImprover,
-    importers.alpine_linux.AlpineBasicImprover,
     importers.github.GitHubBasicImprover,
-    importers.nvd.NVDBasicImprover,
 ]
 
 IMPROVERS_REGISTRY = {x.qualified_name: x for x in IMPROVERS_REGISTRY}