From 2fa3bb5bb8683e2b29cfbea31bf8ecff50a8c25f Mon Sep 17 00:00:00 2001
From: Scott Worley <scottworley@scottworley.com>
Date: Fri, 28 Jun 2024 23:50:27 -0700
Subject: [PATCH] Support "tag <tag>" syntax for fetching tags

---
 Changelog         |  1 +
 git_cache.py      | 12 +++++++++---
 test_git_cache.py | 22 ++++++++++++++++++++++
 3 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/Changelog b/Changelog
index 8075597..59085ea 100644
--- a/Changelog
+++ b/Changelog
@@ -1,4 +1,5 @@
 ## [Unreleased]
+- Support "tag <tag>" syntax for fetching tags
 
 
 ## [1.4.4] - 2024-06-03
diff --git a/git_cache.py b/git_cache.py
index 8171b48..76c0ed4 100644
--- a/git_cache.py
+++ b/git_cache.py
@@ -79,7 +79,7 @@ def is_ancestor(repo: Repo, descendant: RefOrRev, ancestor: RefOrRev) -> bool:
                               'merge-base',
                               '--is-ancestor',
                               ancestor,
-                              descendant],
+                              descendant.removeprefix('tag ')],
                              check=False)
     return process.returncode == 0
 
@@ -178,9 +178,12 @@ def _git_fetch(
         repo: Repo,
         ref: Ref,
         force: bool = False) -> None:
+    refargs = (['tag', ref.removeprefix('tag ')]
+               if ref.startswith('tag ')
+               else [f'{ref}:{ref}'])
     subprocess.run(['git', '-C', cachedir, 'fetch'] +
                    (['--force'] if force else []) +
-                   [repo, f'{ref}:{ref}'], check=True)
+                   [repo] + refargs, check=True)
 
 
 def fetch(repo: Repo, ref: Ref, force: bool = False) -> Tuple[Path, Rev]:
@@ -201,7 +204,10 @@ def fetch(repo: Repo, ref: Ref, force: bool = False) -> Tuple[Path, Rev]:
     logging.debug('Fetching ref "%s" from %s', ref, repo)
     _git_fetch(cachedir, repo, ref, force=force)
 
-    with open(os.path.join(cachedir, 'refs', 'heads', ref), encoding='utf-8') as rev_file:
+    rev_path = (['tags', ref.removeprefix('tag ')]
+                if ref.startswith('tag ')
+                else ['heads', ref])
+    with open(os.path.join(cachedir, 'refs', *rev_path), encoding='utf-8') as rev_file:
         rev = Rev(rev_file.read(999).strip())
     verify_ancestry(repo, ref, rev, force=force)
     _log_fetch(repo, ref, rev, force=force)
diff --git a/test_git_cache.py b/test_git_cache.py
index 1845c01..3678171 100644
--- a/test_git_cache.py
+++ b/test_git_cache.py
@@ -261,6 +261,28 @@ class TestGitCache(unittest.TestCase):
         git_cache.ensure_rev_available(
             self.upstream, 'main', rev, force=True)
 
+    def test_fetch_tag(self) -> None:
+        _git(self.upstream, 'tag', 'v1.2.3')
+        d, rev = git_cache.fetch(self.upstream, 'tag v1.2.3')
+        self.assertEqual(_git(d, 'show', f'{rev}:file'), b'Contents')
+
+    def test_ensure_tag(self) -> None:
+        rev = _git(self.upstream, 'log', '--format=%H', '-n1').strip().decode()
+        _git(self.upstream, 'tag', 'v1.2.3')
+        d = git_cache.ensure_rev_available(self.upstream, 'tag v1.2.3', rev)
+        self.assertEqual(_git(d, 'show', f'{rev}:file'), b'Contents')
+
+    def test_fetch_annotated_tag(self) -> None:
+        _git(self.upstream, 'tag', '--annotate', '-m', 'Tag', 'v1.2.3')
+        d, rev = git_cache.fetch(self.upstream, 'tag v1.2.3')
+        self.assertEqual(_git(d, 'show', f'{rev}:file'), b'Contents')
+
+    def test_ensure_annotated_tag(self) -> None:
+        rev = _git(self.upstream, 'log', '--format=%H', '-n1').strip().decode()
+        _git(self.upstream, 'tag', '--annotate', '-m', 'Tag', 'v1.2.3')
+        d = git_cache.ensure_rev_available(self.upstream, 'tag v1.2.3', rev)
+        self.assertEqual(_git(d, 'show', f'{rev}:file'), b'Contents')
+
 
 if __name__ == '__main__':
     unittest.main()
-- 
2.44.1