chore: add ability to update the global changelog via release-init command (googleapis#14349)

parthea · web-flow · commit 55fd696c05f1 · 2025-09-04T13:07:45.000-04:00
This PR builds on top of googleapis#14327 and adds the ability to update the client library version in the root [CHANGELOG.md](https://github.com/googleapis/google-cloud-python/blob/main/CHANGELOG.md) Towards googleapis/librarian#886
diff --git a/.generator/cli.py b/.generator/cli.py
@@ -47,6 +47,32 @@
 SOURCE_DIR = "source"
 
 
+def _read_text_file(path: str) -> str:
+    """Helper function that reads a text file path and returns the content.
+
+    Args:
+        path(str): The file path to read.
+
+    Returns:
+        str: The contents of the file.
+    """
+
+    with open(path, "r") as f:
+        return f.read()
+
+
+def _write_text_file(path: str, updated_content: str):
+    """Helper function that writes a text file path with the given content.
+
+    Args:
+        path(str): The file path to write.
+        updated_content(str): The contents to write to the file.
+    """
+
+    with open(path, "w") as f:
+        f.write(updated_content)
+
+
 def _read_json_file(path: str) -> Dict:
     """Helper function that reads a json file path and returns the loaded json content.
 
@@ -449,6 +475,32 @@ def _get_libraries_to_prepare_for_release(library_entries: Dict) -> List[dict]:
     ]
 
 
+def _update_global_changelog(changelog_src: str, changelog_dest: str, all_libraries: List[dict]):
+    """Updates the versions of libraries in the main CHANGELOG.md.
+
+    Args:
+        changelog_src(str): Path to the changelog file to read.
+        changelog_dest(str): Path to the changelog file to write.
+        all_libraries(Dict): Dictionary containing all of the library versions to
+        modify.
+    """
+
+    def replace_version_in_changelog(content):
+        new_content = content
+        for library in all_libraries:
+            package_name = library["id"]
+            version = library["version"]
+            # Find the entry for the given package in the format`<package name>==<version>`
+            # Replace the `<version>` part of the string.
+            pattern = re.compile(f"(\\[{re.escape(package_name)})(==)([\\d\\.]+)(\\])")
+            replacement = f"\\g<1>=={version}\\g<4>"
+            new_content = pattern.sub(replacement, new_content)
+        return new_content
+
+    updated_content = replace_version_in_changelog(_read_text_file(changelog_src))
+    _write_text_file(changelog_dest, updated_content)
+
+
 def handle_release_init(
     librarian: str = LIBRARIAN_DIR, repo: str = REPO_DIR, output: str = OUTPUT_DIR
 ):
@@ -478,15 +530,18 @@ def handle_release_init(
             request_data
         )
 
-        # TODO(https://github.com/googleapis/google-cloud-python/pull/14349):
-        # Update library global changelog file.
+        _update_global_changelog(
+            f"{repo}/CHANGELOG.md",
+            f"{output}/CHANGELOG.md",
+            libraries_to_prep_for_release,
+        )
 
         # Prepare the release for each library by updating the
         # library specific version files and library specific changelog.
         for library_release_data in libraries_to_prep_for_release:
             # TODO(https://github.com/googleapis/google-cloud-python/pull/14350):
             # Update library specific version files.
-            # TODO(https://github.com/googleapis/google-cloud-python/pull/14351):
+            # TODO(https://github.com/googleapis/google-cloud-python/pull/14353):
             # Conditionally update the library specific CHANGELOG if there is a change.
             pass
 
diff --git a/.generator/test_cli.py b/.generator/test_cli.py
@@ -16,6 +16,7 @@
 import logging
 import os
 import subprocess
+import unittest.mock
 from unittest.mock import MagicMock, mock_open
 
 import pytest
@@ -34,9 +35,12 @@
     _get_libraries_to_prepare_for_release,
     _locate_and_extract_artifact,
     _read_json_file,
+    _read_text_file,
     _run_individual_session,
     _run_nox_sessions,
     _run_post_processor,
+    _update_global_changelog,
+    _write_text_file,
     handle_build,
     handle_configure,
     handle_generate,
@@ -461,7 +465,7 @@ def test_read_valid_json(mocker):
     assert result == {"key": "value"}
 
 
-def test_file_not_found(mocker):
+def test_json_file_not_found(mocker):
     """Tests behavior when the file does not exist."""
     mocker.patch("builtins.open", side_effect=FileNotFoundError("No such file"))
 
@@ -505,10 +509,11 @@ def test_get_libraries_to_prepare_for_release(mock_release_init_request_file):
     assert libraries_to_prep_for_release[0]["release_triggered"]
 
 
-def test_handle_release_init_success(mock_release_init_request_file):
+def test_handle_release_init_success(mocker, mock_release_init_request_file):
     """
     Simply tests that `handle_release_init` runs without errors.
     """
+    mocker.patch("cli._update_global_changelog", return_value=None)
     handle_release_init()
 
 
@@ -518,3 +523,51 @@ def test_handle_release_init_fail():
     """
     with pytest.raises(ValueError):
         handle_release_init()
+
+
+def test_read_valid_text_file(mocker):
+    """Tests reading a valid text file."""
+    mock_content = "some text"
+    mocker.patch("builtins.open", mocker.mock_open(read_data=mock_content))
+    result = _read_text_file("fake/path.txt")
+    assert result == "some text"
+
+
+def test_text_file_not_found(mocker):
+    """Tests behavior when the file does not exist."""
+    mocker.patch("builtins.open", side_effect=FileNotFoundError("No such file"))
+
+    with pytest.raises(FileNotFoundError):
+        _read_text_file("non/existent/path.text")
+
+
+def test_write_text_file():
+    """Tests writing a text file.
+    See https://docs.python.org/3/library/unittest.mock.html#mock-open
+    """
+    m = mock_open()
+
+    with unittest.mock.patch("cli.open", m):
+        _write_text_file("fake_path.txt", "modified content")
+
+        handle = m()
+        handle.write.assert_called_once_with("modified content")
+
+
+def test_update_global_changelog(mocker, mock_release_init_request_file):
+    """Tests that the global changelog is updated
+    with the new version for a given library.
+    See https://docs.python.org/3/library/unittest.mock.html#mock-open
+    """
+    m = mock_open()
+    request_data = _read_json_file(f"{LIBRARIAN_DIR}/{RELEASE_INIT_REQUEST_FILE}")
+    libraries = _get_libraries_to_prepare_for_release(request_data)
+
+    with unittest.mock.patch("cli.open", m):
+        mocker.patch(
+            "cli._read_text_file", return_value="[google-cloud-language==1.2.2]"
+        )
+        _update_global_changelog("source", "output", libraries)
+
+        handle = m()
+        handle.write.assert_called_once_with("[google-cloud-language==1.2.3]")
