chore: add script to generate release notes based on commit history

.github/release-note-generation/generate_module_notes.py

@@ -0,0 +1,278 @@
+import argparse
+import re
+import subprocess
+import sys
+
+
+def run_cmd(cmd, cwd=None):
+    """Runs a shell command and returns the output."""
+    result = subprocess.run(
+        cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True, cwd=cwd
+    )
+    if result.returncode != 0:
+        print(f"Error running command: {' '.join(cmd)}", file=sys.stderr)
+        print(result.stderr, file=sys.stderr)
+        sys.exit(result.returncode)
+    return result.stdout
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Generate release notes based on commit history for a specific module."
+    )
+    parser.add_argument(
+        "--module", required=True, help="Module name as specified in versions.txt"
+    )
+    parser.add_argument(
+        "--directory", required=True, help="Path in the monorepo where the module has code"
+    )
+    parser.add_argument("--version", required=True, help="Target version")
+    parser.add_argument(
+        "--short-name", help="Module short-name used in commit overrides (e.g., aiplatform). Omit for repo-wide generation."
+    )
+    args = parser.parse_args()
+
+    module = args.module
+    directory = args.directory
+    target_version = args.version
+
+    # 1. Scan backwards through git history of versions.txt
+    # We use -G to find commits that modified lines matching the module name.
+    # We use --first-parent to ignore merge noise.
+    log_cmd = [
+        "git",
+        "log",
+        "--oneline",
+        "--first-parent",
+        f"-G^{module}:",
+        "--",
+        "versions.txt",
+    ]
+    log_output = run_cmd(log_cmd)
+
+    commits = [line.split()[0] for line in log_output.splitlines() if line]
+
+    target_commit = None
+    prev_commit = None
+    prev_version = None
+
+    for commit in commits:
+        # Get content of versions.txt at this commit
+        show_cmd = ["git", "show", f"{commit}:versions.txt"]
+        try:
+            content = run_cmd(show_cmd)
+        except SystemExit:
+            continue  # Ignore errors if file couldn't be read
+
+        # Find the line for the module
+        pattern = re.compile(rf"^{module}:([^:]+):([^:]+)$")
+        for line in content.splitlines():
+            match = pattern.match(line)
+            if match:
+                released_ver = match.group(1)
+                current_ver = match.group(2)
+
+                # Condition for target version
+                if released_ver == target_version and not target_commit:
+                    target_commit = commit
+                    print(f"Found target version {target_version} at {commit}")
+
+                # Condition for previous non-snapshot version
+                # We ignore snapshot versions by checking both fields.
+                elif (
+                    target_commit
+                    and released_ver != target_version
+                    and "-SNAPSHOT" not in released_ver
+                    and "-SNAPSHOT" not in current_ver
+                ):
+                    prev_commit = commit
+                    prev_version = released_ver
+                    print(f"Found previous version {released_ver} at {commit}")
+                    break
+        if prev_commit:
+            break
+
+    if not target_commit:
+        print(
+            f"Target version {target_version} not found in history for module {module}."
+        )
+        sys.exit(1)
+
+    # Fallback for initial version if no previous version found
+    if not prev_commit:
+        print(
+            f"Previous version not found in history for module {module}."
+        )
+        # Find the first commit affecting that directory
+        first_commit_cmd = [
+            "git",
+            "log",
+            "--reverse",
+            "--oneline",
+            "--first-parent",
+            "--",
+            directory,
+        ]
+        try:
+            first_commit_output = run_cmd(first_commit_cmd)
+            if first_commit_output:
+                prev_commit = first_commit_output.splitlines()[0].split()[0]
+                print(f"Using first commit affecting directory as base: {prev_commit}")
+            else:
+                print(f"No history found for directory {directory}.")
+                sys.exit(1)
+        except SystemExit:
+            sys.exit(1)
+
+    print(
+        f"Generating notes between {prev_commit} and {target_commit} for directory {directory}"
+    )
+
+    # 2. Generate commit history in that range affecting that directory
+    # Use --first-parent to ignore merge noise.
+    # Use format that includes hash, subject, and body
+    notes_cmd = [
+        "git",
+        "log",
+        "--format=%H %s%n%b%n--END_OF_COMMIT--",
+        "--first-parent",
+        f"{prev_commit}..{target_commit}",
+        "--",
+        directory,
+    ]
+    notes_output = run_cmd(notes_cmd)
+
+    # Filter commit titles based on allowed prefixes and categorize them
+    # Supports scopes in parentheses, e.g., feat(spanner):
+    prefix_regex = re.compile(r"^(feat|fix|deps|docs)(\([^)]+\))?(!)?:")
+
+    breaking_changes = []
+    features = []
+    bug_fixes = []
+    dependency_upgrades = []
+    documentation = []
+
+    def categorize_and_append(commit_hash, text):
+        match = prefix_regex.match(text)
+        if not match:
+            return
+
+        prefix = match.group(1)
+        is_breaking = match.group(3) == "!"
+
+        if is_breaking:
+            breaking_changes.append(f"{commit_hash[:11]} {text}")
+        elif prefix == "feat":
+            features.append(f"{commit_hash[:11]} {text}")
+        elif prefix == "fix":
+            bug_fixes.append(f"{commit_hash[:11]} {text}")
+        elif prefix == "deps":
+            dependency_upgrades.append(f"{commit_hash[:11]} {text}")
+        elif prefix == "docs":
+            documentation.append(f"{commit_hash[:11]} {text}")
+
+    commits_data = notes_output.split("--END_OF_COMMIT--")
+
+    for commit_data in commits_data:
+        commit_data = commit_data.strip()
+        if not commit_data:
+            continue
+
+        lines = commit_data.splitlines()
+        if not lines:
+            continue
+
+        header_parts = lines[0].split(" ", 1)
+        commit_hash = header_parts[0]
+        subject = header_parts[1] if len(header_parts) > 1 else ""
+
+        body = "\n".join(lines[1:])
+
+        # Check for override in the entire message
+        if "BEGIN_COMMIT_OVERRIDE" in body or "BEGIN_COMMIT_OVERRIDE" in subject:
+            match = re.search(r"BEGIN_COMMIT_OVERRIDE(.*?)END_COMMIT_OVERRIDE", commit_data, re.DOTALL)
+            if match:
+                override_content = match.group(1)
+                current_item = []
+                in_module_item = False
+
+                for line in override_content.splitlines():
+                    line_stripped = line.strip()
+                    if not line_stripped:
+                        continue
+
+                    # Check if it's a new item using regex
+                    is_new_item = prefix_regex.match(line_stripped)
+
+                    if is_new_item:
+                        # If we were in an item, save it
+                        if in_module_item and current_item:
+                            categorize_and_append(commit_hash, " ".join(current_item))
+                            current_item = []
+                            in_module_item = False
+
+                        # Check if this new item is for our module or if we want all
+                        should_include = False
+                        if args.short_name:
+                            if f"[{args.short_name}]" in line_stripped:
+                                should_include = True
+                        else:
+                            should_include = True
+
+                        if should_include:
+                            in_module_item = True
+                            current_item.append(line_stripped)
+                    elif in_module_item:
+                        # Continuation line
+                        if line_stripped.startswith(("PiperOrigin-RevId:", "Source Link:")):
+                            continue
+                        if line_stripped in ("END_NESTED_COMMIT", "BEGIN_NESTED_COMMIT"):
+                            continue
+                        current_item.append(line_stripped)
+
+                # Save the last item if we were in one
+                if in_module_item and current_item:
+                    categorize_and_append(commit_hash, " ".join(current_item))
+
+            # Ignore the title since there was an override
+            continue
+
+        # Fallback to title check if no override
+        if prefix_regex.match(subject):
+            categorize_and_append(commit_hash, subject)
+
+    print("\nRelease Notes:")
+    if breaking_changes:
+        print("### ⚠ BREAKING CHANGES\n")
+        for item in breaking_changes:
+            print(f"* {item}")
+        print()
+
+    if features:
+        print("### Features\n")
+        for item in features:
+            print(f"* {item}")
+        print()
+
+    if bug_fixes:
+        print("### Bug Fixes\n")
+        for item in bug_fixes:
+            print(f"* {item}")
+        print()
+
+    if dependency_upgrades:
+        print("### Dependencies\n")
+        for item in dependency_upgrades:
+            print(f"* {item}")
+        print()
+
+    if documentation:
+        print("### Documentation\n")
+        for item in documentation:
+            print(f"* {item}")
+        print()
+
+
+
+if __name__ == "__main__":
+    main()