[releaser] Automate branch selection for porting changelog #646

Implemented automated branch detection to avoid choosing between
master and main when only one exists.

Fixes #646

Author: prathmeshkulkarni-coder

openwisp_utils/releaser/release.py

@@ -20,6 +20,7 @@
 from openwisp_utils.releaser.utils import (
     SkipSignal,
     adjust_markdown_headings,
+    branch_exists,
     demote_markdown_headings,
     format_file_with_docstrfmt,
     get_current_branch,
@@ -176,10 +177,17 @@ def port_changelog_to_main(gh, config, version, changelog_body, original_branch)
         full_block_to_port = f"{version_header}\n{underline}\n\n{changelog_body}"
 
     try:
-        main_branch = questionary.select(
-            "Which branch should the changelog be ported to?",
-            choices=MAIN_BRANCHES,
-        ).ask()
+        main_exists = branch_exists("main")
+        master_exists = branch_exists("master")
+        if main_exists and master_exists:
+            main_branch = questionary.select(
+                "Which branch should the changelog be ported to?",
+                choices=MAIN_BRANCHES,
+            ).ask()
+        elif main_exists:
+            main_branch = "main"
+        else:
+            main_branch = "master"
 
         if not main_branch:
             print("Porting cancelled.")

openwisp_utils/releaser/tests/test_release.py

@@ -1,4 +1,4 @@
-from unittest.mock import MagicMock, patch
+from unittest.mock import MagicMock, call, patch
 
 import pytest
 from openwisp_utils.releaser.release import check_prerequisites
@@ -155,26 +155,86 @@ def test_main_flow_pr_merge_wait(mock_all):
 @patch("openwisp_utils.releaser.release.update_changelog_file")
 @patch("openwisp_utils.releaser.release.format_file_with_docstrfmt")
 @patch("openwisp_utils.releaser.release.subprocess.run")
+@patch("openwisp_utils.releaser.release.branch_exists")
 @patch("openwisp_utils.releaser.release.questionary")
 def test_port_changelog_to_main_flow(
-    mock_questionary, mock_subprocess, mock_format_file, mock_update_changelog
+    mock_questionary,
+    mock_branch_exists,
+    mock_subprocess,
+    mock_format_file,
+    mock_update_changelog,
 ):
     """Tests the changelog porting process for both RST and MD files, and the cancellation path."""
     mock_gh = MagicMock()
     mock_config_rst = {"changelog_path": "CHANGES.rst"}
+    # Both branches exist: user is asked
+    mock_branch_exists.return_value = True
     mock_questionary.select.return_value.ask.return_value = "main"
     port_changelog_to_main(mock_gh, mock_config_rst, "1.1.1", "- fix", "1.1.x")
     mock_gh.create_pr.assert_called_once()
     mock_format_file.assert_called_once_with("CHANGES.rst")
 
     mock_gh.reset_mock()
 
-    # Test Cancellation path
+    # Test Cancellation path (when both branches exist and user cancels)
     mock_questionary.select.return_value.ask.return_value = None
     port_changelog_to_main(mock_gh, mock_config_rst, "1.1.1", "- fix", "1.1.x")
     mock_gh.create_pr.assert_not_called()
 
 
+@patch("openwisp_utils.releaser.release.update_changelog_file")
+@patch("openwisp_utils.releaser.release.subprocess.run")
+@patch("openwisp_utils.releaser.release.branch_exists")
+def test_port_changelog_only_master_exists(
+    mock_branch_exists, mock_subprocess, mock_update_changelog
+):
+    """`master` is auto-selected when `main` does not exist locally."""
+    mock_gh = MagicMock()
+    mock_config = {"changelog_path": "CHANGES.rst"}
+    # Simulate: main=False, master=True
+    mock_branch_exists.side_effect = lambda name: name == "master"
+    port_changelog_to_main(mock_gh, mock_config, "1.1.1", "- fix", "1.1.x")
+    mock_gh.create_pr.assert_called_once()
+    # Verify PR was opened against master
+    assert mock_gh.create_pr.call_args[0][1] == "master"
+
+
+@patch("openwisp_utils.releaser.release.update_changelog_file")
+@patch("openwisp_utils.releaser.release.subprocess.run")
+@patch("openwisp_utils.releaser.release.branch_exists")
+def test_port_changelog_only_main_exists(
+    mock_branch_exists, mock_subprocess, mock_update_changelog
+):
+    """`main` is auto-selected when it exists and `master` does not."""
+    mock_gh = MagicMock()
+    mock_config = {"changelog_path": "CHANGES.rst"}
+    # Simulate: main=True, master=False
+    mock_branch_exists.side_effect = lambda name: name == "main"
+    port_changelog_to_main(mock_gh, mock_config, "1.1.1", "- fix", "1.1.x")
+    mock_gh.create_pr.assert_called_once()
+    # Verify PR was opened against main
+    assert mock_gh.create_pr.call_args[0][1] == "main"
+
+
+@patch("openwisp_utils.releaser.release.update_changelog_file")
+@patch("openwisp_utils.releaser.release.subprocess.run")
+@patch("openwisp_utils.releaser.release.branch_exists")
+@patch("openwisp_utils.releaser.release.questionary")
+def test_port_changelog_both_branches_prompts_user(
+    mock_questionary, mock_branch_exists, mock_subprocess, mock_update_changelog
+):
+    """User is prompted to choose when both `main` and `master` exist."""
+    mock_gh = MagicMock()
+    mock_config = {"changelog_path": "CHANGES.rst"}
+    # Both branches exist
+    mock_branch_exists.return_value = True
+    mock_questionary.select.return_value.ask.return_value = "master"
+    port_changelog_to_main(mock_gh, mock_config, "1.1.1", "- fix", "1.1.x")
+    mock_questionary.select.assert_called_once()
+    mock_gh.create_pr.assert_called_once()
+    assert mock_gh.create_pr.call_args[0][1] == "master"
+
+
 def test_main_bugfix_flow_with_porting(mock_all, mocker):
     """Tests the main release flow for a bugfix, including accepting the changelog port."""
     mock_all["_git_command_map"][

openwisp_utils/releaser/utils.py

@@ -85,6 +85,17 @@ def get_current_branch():
     return result.stdout.strip()
 
 
+def branch_exists(branch_name):
+    """Check if a Git branch exists locally."""
+    result = subprocess.run(
+        ["git", "show-ref", "--verify", "--quiet", f"refs/heads/{branch_name}"],
+        capture_output=True,
+        text=True,
+        encoding="utf-8",
+    )
+    return result.returncode == 0
+
+
 def rst_to_markdown(text):
     """Convert reStructuredText to Markdown using pypandoc."""
     escaped_text = re.sub(r"(?<!`)_", r"\\_", text)