link_sources: fix parsing of non-wheel non-sdist links

src/poetry/repositories/link_sources/base.py

@@ -49,7 +49,7 @@ class LinkSource:
         for link in self.links:
             pkg = self.link_package_data(link)
 
-            if pkg and pkg.name == name and pkg.version and pkg.version not in seen:
+            if pkg and pkg.name == name and pkg.version not in seen:
                 seen.add(pkg.version)
                 yield pkg.version
 
@@ -58,7 +58,7 @@ class LinkSource:
         for link in self.links:
             pkg = self.link_package_data(link)
 
-            if pkg and pkg.name and pkg.version:
+            if pkg:
                 yield pkg
 
     @property
@@ -66,8 +66,9 @@ class LinkSource:
     def links(self) -> Iterator[Link]:
         raise NotImplementedError()
 
-    def link_package_data(self, link: Link) -> Package | None:
-        name, version = None, None
+    @classmethod
+    def link_package_data(cls, link: Link) -> Package | None:
+        name, version_string, version = None, None, None
         m = wheel_file_re.match(link.filename) or sdist_file_re.match(link.filename)
 
         if m:
@@ -75,10 +76,12 @@ class LinkSource:
             version_string = m.group("ver")
         else:
             info, ext = link.splitext()
-            match = self.VERSION_REGEX.match(info)
+            match = cls.VERSION_REGEX.match(info)
             if match:
+                name = match.group(1)
                 version_string = match.group(2)
 
+        if version_string:
             try:
                 version = Version.parse(version_string)
             except ValueError:
@@ -87,7 +90,10 @@ class LinkSource:
                 )
                 return None
 
-        return Package(name, version, source_url=link.url)
+        pkg = None
+        if name and version:
+            pkg = Package(name, version, source_url=link.url)
+        return pkg
 
     def links_for_version(self, name: str, version: Version) -> Iterator[Link]:
         name = canonicalize_name(name)
@@ -95,7 +101,7 @@ class LinkSource:
         for link in self.links:
             pkg = self.link_package_data(link)
 
-            if pkg and pkg.name == name and pkg.version and pkg.version == version:
+            if pkg and pkg.name == name and pkg.version == version:
                 yield link
 
     def clean_link(self, url: str) -> str:

tests/repositories/link_sources/test_base.py

+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+from typing import Iterable
+from unittest.mock import PropertyMock
+
+import pytest
+
+from poetry.core.packages.package import Package
+from poetry.core.packages.utils.link import Link
+from poetry.core.semver.version import Version
+
+from poetry.repositories.link_sources.base import LinkSource
+
+
+if TYPE_CHECKING:
+    from pytest_mock import MockerFixture
+
+
+@pytest.fixture
+def link_source(mocker: MockerFixture) -> LinkSource:
+    url = "https://example.org"
+    link_source = LinkSource(url)
+    mocker.patch(
+        f"{LinkSource.__module__}.{LinkSource.__qualname__}.links",
+        new_callable=PropertyMock,
+        return_value=iter(
+            [
+                Link(f"{url}/demo-0.1.0.tar.gz"),
+                Link(f"{url}/demo-0.1.0_invalid.tar.gz"),
+                Link(f"{url}/invalid.tar.gz"),
+                Link(f"{url}/demo-0.1.0-py2.py3-none-any.whl"),
+                Link(f"{url}/demo-0.1.1.tar.gz"),
+            ]
+        ),
+    )
+    return link_source
+
+
+@pytest.mark.parametrize(
+    "filename, expected",
+    [
+        ("demo-0.1.0-py2.py3-none-any.whl", Package("demo", "0.1.0")),
+        ("demo-0.1.0.tar.gz", Package("demo", "0.1.0")),
+        ("demo-0.1.0.egg", Package("demo", "0.1.0")),
+        ("demo-0.1.0_invalid-py2.py3-none-any.whl", None),  # invalid version
+        ("demo-0.1.0_invalid.egg", None),  # invalid version
+        ("no-package-at-all.txt", None),
+    ],
+)
+def test_link_package_data(filename: str, expected: Package | None) -> None:
+    link = Link(f"https://example.org/{filename}")
+    assert LinkSource.link_package_data(link) == expected
+
+
+@pytest.mark.parametrize(
+    "name, expected",
+    [
+        ("demo", {Version.parse("0.1.0"), Version.parse("0.1.1")}),
+        ("invalid", set()),
+    ],
+)
+def test_versions(name: str, expected: set[Version], link_source: LinkSource) -> None:
+    assert set(link_source.versions(name)) == expected
+
+
+def test_packages(link_source: LinkSource) -> None:
+    expected = {
+        Package("demo", "0.1.0"),
+        Package("demo", "0.1.0"),
+        Package("demo", "0.1.1"),
+    }
+    assert set(link_source.packages) == expected
+
+
+@pytest.mark.parametrize(
+    "version_string, filenames",
+    [
+        ("0.1.0", ["demo-0.1.0.tar.gz", "demo-0.1.0-py2.py3-none-any.whl"]),
+        ("0.1.1", ["demo-0.1.1.tar.gz"]),
+        ("0.1.2", []),
+    ],
+)
+def test_links_for_version(
+    version_string: str, filenames: Iterable[str], link_source: LinkSource
+) -> None:
+    version = Version.parse(version_string)
+    expected = {Link(f"{link_source.url}/{name}") for name in filenames}
+    assert set(link_source.links_for_version("demo", version)) == expected