chore(.generator): release staging preview support

.generator/cli.py

@@ -323,6 +323,32 @@ def _get_library_id(request_data: Dict) -> str:
     return library_id
 
 
+def _get_package_name(library_id: str) -> str:
+    """Extracts the folder name from the library id by removing any -preview suffix."""
+    if library_id.endswith("-preview"):
+        return library_id[:-8]
+    return library_id
+
+
+def _get_library_path(library_id: str, is_mono_repo: bool) -> str:
+    """Gets the relative path of the library in the repository.
+
+    Args:
+        library_id(str): The library id.
+        is_mono_repo(bool): True if the current repository is a mono-repo.
+
+    Returns:
+        str: The relative path to the library.
+    """
+    if not is_mono_repo:
+        return "."
+    if library_id.endswith("-preview"):
+        package_name = _get_package_name(library_id)
+        return f"preview-packages/{package_name}"
+    return f"packages/{library_id}"
+
+
+
 def _run_post_processor(output: str, library_id: str, is_mono_repo: bool):
     """Runs the synthtool post-processor on the output directory.
 
@@ -575,7 +601,7 @@ def _get_repo_metadata_file_path(base: str, library_id: str, is_mono_repo: bool)
     Returns:
         str: The absolute path to the .repo-metadata.json file.
     """
-    path_to_library = f"packages/{library_id}" if is_mono_repo else "."
+    path_to_library = _get_library_path(library_id, is_mono_repo)
     return f"{base}/{path_to_library}/.repo-metadata.json"
 
 
@@ -1530,8 +1556,9 @@ def _process_changelog(
                 entry_parts.append(f"* {change[subject_key]} {commit_link}")
 
     new_entry_text = "\n".join(entry_parts)
+    package_name = _get_package_name(library_id)
     anchor_pattern = re.compile(
-        rf"(\[1\]: https://pypi\.org/project/{library_id}/#history)",
+        rf"(\[1\]: https://pypi\.org/project/{package_name}/#history)",
         re.MULTILINE,
     )
     replacement_text = f"\\g<1>\n\n{new_entry_text}"
@@ -1570,11 +1597,12 @@ def _update_changelog_for_library(
         tag_format(str): The format of the git tag.
     """
     if is_mono_repo:
-        relative_path = f"packages/{library_id}/CHANGELOG.md"
-        docs_relative_path = f"packages/{library_id}/docs/CHANGELOG.md"
+        path_to_library = _get_library_path(library_id, is_mono_repo)
+        relative_path = f"{path_to_library}/CHANGELOG.md"
+        docs_relative_path = f"{path_to_library}/docs/CHANGELOG.md"
     else:
         relative_path = "CHANGELOG.md"
-        docs_relative_path = f"docs/CHANGELOG.md"
+        docs_relative_path = "docs/CHANGELOG.md"
 
     changelog_src = f"{repo}/{relative_path}"
     changelog_dest = f"{output}/{relative_path}"
@@ -1670,7 +1698,7 @@ def handle_release_stage(
                     f"{library_id} version: {previous_version}\n"
                 )
 
-            path_to_library = f"packages/{library_id}" if is_mono_repo else "."
+            path_to_library = _get_library_path(library_id, is_mono_repo)
 
             _update_version_for_library(repo, output, path_to_library, version)
             if library_changes is not None:

.generator/test_cli.py

@@ -48,6 +48,8 @@
     _get_api_generator_options,
     _get_library_dist_name,
     _get_library_id,
+    _get_package_name,
+    _get_library_path,
     _get_libraries_to_prepare_for_release,
     _get_new_library_config,
     _get_previous_version,
@@ -1437,6 +1439,38 @@ def test_process_changelog_success():
     assert result == expected_result
 
 
+def test_process_changelog_success_preview():
+    """Tests that a preview package updates its changelog correctly when the anchor has the standard package name."""
+    current_date = datetime.now().strftime("%Y-%m-%d")
+    mock_content = """# Changelog\n[PyPI History][1]\n[1]: https://pypi.org/project/google-cloud-language/#history\n
+## [1.2.2](https://github.com/googleapis/google-cloud-python/compare/google-cloud-language-v1.2.1...google-cloud-language-v1.2.2) (2025-06-11)"""
+    expected_result = f"""# Changelog\n[PyPI History][1]\n[1]: https://pypi.org/project/google-cloud-language/#history\n
+## [1.2.3](https://github.com/googleapis/google-cloud-python/compare/google-cloud-language-v1.2.2...google-cloud-language-v1.2.3) ({current_date})\n\n
+### Documentation\n
+* fix typo in BranchRule comment ([9461532e7d19c8d71709ec3b502e5d81340fb661](https://github.com/googleapis/google-cloud-python/commit/9461532e7d19c8d71709ec3b502e5d81340fb661))\n\n
+### Features\n
+* add new UpdateRepository API ([9461532e7d19c8d71709ec3b502e5d81340fb661](https://github.com/googleapis/google-cloud-python/commit/9461532e7d19c8d71709ec3b502e5d81340fb661))\n\n
+### Bug Fixes\n
+* some fix ([1231532e7d19c8d71709ec3b502e5d81340fb661](https://github.com/googleapis/google-cloud-python/commit/1231532e7d19c8d71709ec3b502e5d81340fb661))
+* another fix ([1241532e7d19c8d71709ec3b502e5d81340fb661](https://github.com/googleapis/google-cloud-python/commit/1241532e7d19c8d71709ec3b502e5d81340fb661))\n
+## [1.2.2](https://github.com/googleapis/google-cloud-python/compare/google-cloud-language-v1.2.1...google-cloud-language-v1.2.2) (2025-06-11)"""
+    version = "1.2.3"
+    previous_version = "1.2.2"
+    library_id = "google-cloud-language-preview"
+    tag_format = "google-cloud-language-v{version}"
+
+    result = _process_changelog(
+        mock_content,
+        _MOCK_LIBRARY_CHANGES,
+        version,
+        previous_version,
+        library_id,
+        "googleapis/google-cloud-python",
+        tag_format,
+    )
+    assert result == expected_result
+
+
 def test_process_changelog_failure():
     """Tests that value error is raised if the changelog anchor string cannot be found"""
     with pytest.raises(ValueError):
@@ -2045,3 +2079,53 @@ def test_get_repo_name_from_repo_metadata_missing_repo(mocker):
     mocker.patch("cli._read_json_file", return_value={})
     with pytest.raises(ValueError):
         _get_repo_name_from_repo_metadata("base", "library_id", False)
+
+
+def test_get_package_name():
+    assert _get_package_name("google-cloud-language") == "google-cloud-language"
+    assert _get_package_name("google-cloud-language-preview") == "google-cloud-language"
+    assert _get_package_name("google-cloud-language-preview-preview") == "google-cloud-language-preview"
+
+
+@pytest.mark.parametrize(
+    "library_id, is_mono_repo, expected_path",
+    [
+        ("google-cloud-language", True, "packages/google-cloud-language"),
+        ("google-cloud-language-preview", True, "preview-packages/google-cloud-language"),
+        ("google-cloud-language", False, "."),
+        ("google-cloud-language-preview", False, "."),
+    ],
+)
+def test_get_library_path(library_id, is_mono_repo, expected_path):
+    assert _get_library_path(library_id, is_mono_repo) == expected_path
+
+
+def test_update_changelog_for_library_preview_package(mocker):
+    """Tests that _update_changelog_for_library writes to preview-packages directory for preview libraries."""
+    mock_content = """# Changelog
+
+[PyPI History][1]
+
+[1]: https://pypi.org/project/google-cloud-language/#history
+"""
+    mock_read = mocker.patch("cli._read_text_file", return_value=mock_content)
+    mock_write = mocker.patch("cli._write_text_file")
+    mock_path_exists = mocker.patch("cli.os.path.lexists", return_value=True)
+    _update_changelog_for_library(
+        "repo",
+        "output",
+        _MOCK_LIBRARY_CHANGES,
+        "1.2.3",
+        "1.2.2",
+        "google-cloud-language-preview",
+        True,
+        "{id}-v{version}",
+    )
+
+    assert mock_write.call_count == 2
+    mock_write.assert_any_call(
+        "output/preview-packages/google-cloud-language/CHANGELOG.md", mocker.ANY
+    )
+    mock_write.assert_any_call(
+        "output/preview-packages/google-cloud-language/docs/CHANGELOG.md", mocker.ANY
+    )