Initial commit: GitHub Release Monitor CLI tool

CLI tool that tracks GitHub releases or tags from user-defined repositories
and exposes them as a subscribable RSS 2.0 feed.

Features:
- Track releases or tags per repository
- SQLite storage with automatic deduplication
- RSS 2.0 feed with markdown-stripped release notes
- Built-in HTTP server for local feed access
- Rate-limit-aware GitHub API client
- 64 passing tests

tests/test_github.py

@@ -0,0 +1,172 @@
+"""Tests for the GitHub API client."""
+
+import httpx
+import pytest
+import respx
+
+from src.github import GitHubClient, AuthenticationError, NotFoundError
+
+
+@pytest.fixture
+def mock_api():
+    """Enable respx mocking for test scope."""
+    with respx.mock:
+        yield respx
+
+
+class TestFetchReleases:
+    def test_fetch_releases(self, mock_api):
+        mock_api.get("https://api.github.com/repos/owner/repo/releases").mock(
+            return_value=httpx.Response(200, json=[
+                {
+                    "tag_name": "v1.0.0",
+                    "name": "Release v1.0.0",
+                    "body": "# Changelog\n\n- Fixed bug",
+                    "published_at": "2025-01-15T10:30:00Z",
+                    "html_url": "https://github.com/owner/repo/releases/tag/v1.0.0",
+                },
+                {
+                    "tag_name": "v0.9.0",
+                    "name": None,
+                    "body": "",
+                    "published_at": "2025-01-10T08:00:00Z",
+                    "html_url": "https://github.com/owner/repo/releases/tag/v0.9.0",
+                },
+            ])
+        )
+
+        client = GitHubClient(token="fake_token")
+        releases = client.fetch_releases("owner/repo")
+        client.close()
+
+        assert len(releases) == 2
+        assert releases[0]["tag_name"] == "v1.0.0"
+        assert releases[0]["title"] == "Release v1.0.0"
+        assert releases[0]["body"] == "# Changelog\n\n- Fixed bug"
+        assert releases[1]["title"] == "v0.9.0"
+        assert releases[1]["body"] == ""
+
+    def test_fetch_releases_404(self, mock_api):
+        mock_api.get("https://api.github.com/repos/no/such/releases").mock(
+            return_value=httpx.Response(404)
+        )
+
+        client = GitHubClient(token="fake_token")
+        with pytest.raises(NotFoundError):
+            client.fetch_releases("no/such")
+        client.close()
+
+
+class TestFetchTags:
+    def test_fetch_tags(self, mock_api):
+        mock_api.get("https://api.github.com/repos/owner/repo/tags").mock(
+            return_value=httpx.Response(200, json=[
+                {"name": "v1.0.0", "zipball_url": "https://api.github.com/repos/owner/repo/zipball/v1.0.0"},
+                {"name": "v0.9.0", "zipball_url": "https://api.github.com/repos/owner/repo/zipball/v0.9.0"},
+            ])
+        )
+        mock_api.get("https://api.github.com/repos/owner/repo/git/ref/tags/v1.0.0").mock(
+            return_value=httpx.Response(200, json={
+                "object": {
+                    "type": "commit",
+                    "author": {"date": "2025-01-15T10:30:00Z"},
+                }
+            })
+        )
+        mock_api.get("https://api.github.com/repos/owner/repo/git/ref/tags/v0.9.0").mock(
+            return_value=httpx.Response(200, json={
+                "object": {
+                    "type": "commit",
+                    "author": {"date": "2025-01-10T08:00:00Z"},
+                }
+            })
+        )
+
+        client = GitHubClient(token="fake_token")
+        tags = client.fetch_tags("owner/repo")
+        client.close()
+
+        assert len(tags) == 2
+        assert tags[0]["tag_name"] == "v1.0.0"
+        assert tags[0]["title"] == "v1.0.0"
+        assert tags[0]["body"] == ""
+        assert tags[0]["published_at"] == "2025-01-15T10:30:00Z"
+        assert tags[0]["html_url"] == "https://github.com/owner/repo/tags/v1.0.0"
+
+    def test_fetch_tags_with_tag_object(self, mock_api):
+        """When a tag points to a tag object, follow to the commit."""
+        mock_api.get("https://api.github.com/repos/owner/repo/tags").mock(
+            return_value=httpx.Response(200, json=[
+                {"name": "v2.0.0", "zipball_url": "https://api.github.com/..."},
+            ])
+        )
+        mock_api.get("https://api.github.com/repos/owner/repo/git/ref/tags/v2.0.0").mock(
+            return_value=httpx.Response(200, json={
+                "object": {
+                    "type": "tag",
+                    "sha": "abc123",
+                }
+            })
+        )
+        mock_api.get("https://api.github.com/repos/owner/repo/git/commits/abc123").mock(
+            return_value=httpx.Response(200, json={
+                "author": {"date": "2025-02-01T12:00:00Z"}
+            })
+        )
+
+        client = GitHubClient(token="fake_token")
+        tags = client.fetch_tags("owner/repo")
+        client.close()
+
+        assert tags[0]["published_at"] == "2025-02-01T12:00:00Z"
+
+    def test_fetch_tags_fallback_date(self, mock_api):
+        """When git ref fails, use current time as fallback."""
+        mock_api.get("https://api.github.com/repos/owner/repo/tags").mock(
+            return_value=httpx.Response(200, json=[
+                {"name": "v1.0.0", "zipball_url": "https://api.github.com/..."},
+            ])
+        )
+        mock_api.get("https://api.github.com/repos/owner/repo/git/ref/tags/v1.0.0").mock(
+            return_value=httpx.Response(404)
+        )
+
+        client = GitHubClient(token="fake_token")
+        tags = client.fetch_tags("owner/repo")
+        client.close()
+
+        assert tags[0]["published_at"] is not None
+
+
+class TestRepoExists:
+    def test_repo_exists_true(self, mock_api):
+        mock_api.get("https://api.github.com/repos/owner/repo").mock(
+            return_value=httpx.Response(200, json={"full_name": "owner/repo"})
+        )
+        client = GitHubClient(token="fake_token")
+        assert client.repo_exists("owner/repo") is True
+        client.close()
+
+    def test_repo_exists_false(self, mock_api):
+        mock_api.get("https://api.github.com/repos/no/such").mock(
+            return_value=httpx.Response(404)
+        )
+        client = GitHubClient(token="fake_token")
+        assert client.repo_exists("no/such") is False
+        client.close()
+
+
+class TestAuthentication:
+    def test_invalid_token(self, mock_api):
+        mock_api.get("https://api.github.com/rate_limit").mock(
+            return_value=httpx.Response(401)
+        )
+        client = GitHubClient(token="bad_token")
+        with pytest.raises(AuthenticationError, match="401 Unauthorized"):
+            client.validate_token()
+        client.close()
+
+    def test_no_token_skips_validation(self):
+        client = GitHubClient(token=None)
+        client.validate_token()
+        client.close()