Preserve prerelease suffixes when normalizing GitHub tags

Signed-off-by: Ali Zulfiqar <codewithfourtix@gmail.com>

Author: codewithfourtix

src/fetchcode/package_util.py

@@ -119,10 +119,10 @@ def _get_github_packages(purl, version_regex, ignored_tag_regex, default_package
         else:
             version = tag
 
-        version = version.strip("Vv").strip()
+        version = version.strip().lstrip("Vv")
         if "+" in version:
             first, last = version.split("+")
-            first.replace("_", ".")
+            first = first.replace("_", ".")
             version = f"{first}+{last}"
         else:
             version = version.replace("_", ".")

tests/test_github_tag_versions.py

@@ -0,0 +1,22 @@
+import datetime
+
+import pytest
+from packageurl import PackageURL
+
+from fetchcode import package_util
+from fetchcode.packagedcode_models import Package
+
+
+@pytest.mark.parametrize(
+    "tag,expected", [("v1.2-dev", "1.2-dev"), ("v1_2_3+build_4", "1.2.3+build_4")]
+)
+def test_github_tag_version_normalization(monkeypatch, tag, expected):
+    monkeypatch.setattr(
+        package_util.utils,
+        "fetch_github_tags_gql",
+        lambda purl: [(tag, datetime.datetime(2026, 1, 1))],
+    )
+    purl = PackageURL("github", "example", "project")
+    packages = list(package_util.get_github_packages(purl, None, None, Package(**purl.to_dict())))
+    assert packages[0].version == expected
+    assert packages[0].download_url.endswith(f"/{tag}.tar.gz")