Add changelog CLI command and tests (see ChatGPT conversation 2025-12-08) https://chatgpt.com/share/69370663-4eb8-800f-bba9-4f5c42682450

pkgmgr/changelog.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+"""
+Helpers to generate changelog information from Git history.
+
+This module provides a small abstraction around `git log` so that
+CLI commands can request a changelog between two refs (tags, branches,
+commits) without dealing with raw subprocess calls.
+"""
+
+from __future__ import annotations
+
+from typing import Optional
+
+from pkgmgr.git_utils import run_git, GitError
+
+
+def generate_changelog(
+    cwd: str,
+    from_ref: Optional[str] = None,
+    to_ref: Optional[str] = None,
+    include_merges: bool = False,
+) -> str:
+    """
+    Generate a plain-text changelog between two Git refs.
+
+    Parameters
+    ----------
+    cwd:
+        Repository directory in which to run Git commands.
+    from_ref:
+        Optional starting reference (exclusive). If provided together
+        with `to_ref`, the range `from_ref..to_ref` is used.
+        If only `from_ref` is given, the range `from_ref..HEAD` is used.
+    to_ref:
+        Optional end reference (inclusive). If omitted, `HEAD` is used.
+    include_merges:
+        If False (default), merge commits are filtered out.
+
+    Returns
+    -------
+    str
+        The output of `git log` formatted as a simple text changelog.
+        If no commits are found or Git fails, an explanatory message
+        is returned instead of raising.
+    """
+    # Determine the revision range
+    if to_ref is None:
+        to_ref = "HEAD"
+
+    if from_ref:
+        rev_range = f"{from_ref}..{to_ref}"
+    else:
+        rev_range = to_ref
+
+    # Use a custom pretty format that includes tags/refs (%d)
+    cmd = [
+        "log",
+        "--pretty=format:%h %d %s",
+    ]
+    if not include_merges:
+        cmd.append("--no-merges")
+    cmd.append(rev_range)
+
+    try:
+        output = run_git(cmd, cwd=cwd)
+    except GitError as exc:
+        # Do not raise to the CLI, return a human-readable error instead.
+        return (
+            f"[ERROR] Failed to generate changelog in {cwd!r} "
+            f"for range {rev_range!r}:\n{exc}"
+        )
+
+    if not output.strip():
+        return f"[INFO] No commits found for range {rev_range!r}."
+
+    return output.strip()

pkgmgr/cli_core/commands/__init__.py

@@ -4,6 +4,7 @@ from .tools import handle_tools_command
 from .release import handle_release
 from .version import handle_version
 from .make import handle_make
+from .changelog import handle_changelog
 
 __all__ = [
     "handle_repos_command",
@@ -12,4 +13,5 @@ __all__ = [
     "handle_release",
     "handle_version",
     "handle_make",
+    "handle_changelog",
 ]

pkgmgr/cli_core/commands/changelog.py

@@ -0,0 +1,168 @@
+from __future__ import annotations
+
+import os
+import sys
+from typing import Any, Dict, List, Optional, Tuple
+
+from pkgmgr.cli_core.context import CLIContext
+from pkgmgr.get_repo_dir import get_repo_dir
+from pkgmgr.get_repo_identifier import get_repo_identifier
+from pkgmgr.git_utils import get_tags
+from pkgmgr.versioning import SemVer, extract_semver_from_tags
+from pkgmgr.changelog import generate_changelog
+
+
+Repository = Dict[str, Any]
+
+
+def _find_previous_and_current_tag(
+    tags: List[str],
+    target_tag: Optional[str] = None,
+) -> Tuple[Optional[str], Optional[str]]:
+    """
+    Given a list of tags and an optional target tag, determine
+    (previous_tag, current_tag) on the SemVer axis.
+
+    If target_tag is None:
+        - If there are at least two SemVer tags, return (prev, latest).
+        - If there is only one SemVer tag, return (None, latest).
+        - If there are no SemVer tags, return (None, None).
+
+    If target_tag is given:
+        - If target_tag is not a SemVer tag or is unknown, return (None, None).
+        - Otherwise, return (previous_semver_tag, target_tag).
+          If there is no previous SemVer tag, previous_semver_tag is None.
+    """
+    semver_pairs = extract_semver_from_tags(tags)
+    if not semver_pairs:
+        return None, None
+
+    # Sort ascending by SemVer
+    semver_pairs.sort(key=lambda item: item[1])
+
+    tag_to_index = {tag: idx for idx, (tag, _ver) in enumerate(semver_pairs)}
+
+    if target_tag is None:
+        if len(semver_pairs) == 1:
+            return None, semver_pairs[0][0]
+        prev_tag = semver_pairs[-2][0]
+        latest_tag = semver_pairs[-1][0]
+        return prev_tag, latest_tag
+
+    # target_tag is specified
+    if target_tag not in tag_to_index:
+        return None, None
+
+    idx = tag_to_index[target_tag]
+    current_tag = semver_pairs[idx][0]
+    if idx == 0:
+        return None, current_tag
+
+    previous_tag = semver_pairs[idx - 1][0]
+    return previous_tag, current_tag
+
+
+def handle_changelog(
+    args,
+    ctx: CLIContext,
+    selected: List[Repository],
+) -> None:
+    """
+    Handle the 'changelog' command.
+
+    Behaviour:
+    - Without range: show changelog between the last two SemVer tags,
+      or from the single SemVer tag to HEAD, or from the beginning if
+      no tags exist.
+    - With RANGE of the form 'A..B': show changelog between A and B.
+    - With RANGE of the form 'vX.Y.Z': show changelog between the
+      previous SemVer tag and vX.Y.Z (or from start if there is none).
+    """
+
+    if not selected:
+        print("No repositories selected for changelog.")
+        sys.exit(1)
+
+    range_arg: str = getattr(args, "range", "") or ""
+
+    print("pkgmgr changelog")
+    print("=================")
+
+    for repo in selected:
+        # Resolve repository directory
+        repo_dir = repo.get("directory")
+        if not repo_dir:
+            try:
+                repo_dir = get_repo_dir(ctx.repositories_base_dir, repo)
+            except Exception:
+                repo_dir = None
+
+        identifier = get_repo_identifier(repo, ctx.all_repositories)
+
+        if not repo_dir or not os.path.isdir(repo_dir):
+            print(f"\nRepository: {identifier}")
+            print("----------------------------------------")
+            print(
+                "[INFO] Skipped: repository directory does not exist "
+                "locally, changelog generation is not possible."
+            )
+            continue
+
+        print(f"\nRepository: {identifier}")
+        print(f"Path:       {repo_dir}")
+        print("----------------------------------------")
+
+        try:
+            tags = get_tags(cwd=repo_dir)
+        except Exception as exc:
+            print(f"[ERROR] Could not read git tags: {exc}")
+            tags = []
+
+        from_ref: Optional[str] = None
+        to_ref: Optional[str] = None
+
+        if range_arg:
+            # Explicit range provided
+            if ".." in range_arg:
+                # Format: A..B
+                parts = range_arg.split("..", 1)
+                from_ref = parts[0] or None
+                to_ref = parts[1] or None
+            else:
+                # Single tag, compute previous + current
+                prev_tag, cur_tag = _find_previous_and_current_tag(
+                    tags,
+                    target_tag=range_arg,
+                )
+                if cur_tag is None:
+                    print(
+                        f"[WARN] Tag {range_arg!r} not found or not a SemVer tag."
+                    )
+                    print("[INFO] Falling back to full history.")
+                    from_ref = None
+                    to_ref = None
+                else:
+                    from_ref = prev_tag
+                    to_ref = cur_tag
+        else:
+            # No explicit range: last two SemVer tags (or fallback)
+            prev_tag, cur_tag = _find_previous_and_current_tag(tags)
+            from_ref = prev_tag
+            to_ref = cur_tag  # may be None if no tags
+
+        changelog_text = generate_changelog(
+            cwd=repo_dir,
+            from_ref=from_ref,
+            to_ref=to_ref,
+            include_merges=False,
+        )
+
+        if from_ref or to_ref:
+            ref_desc = f"{from_ref or '<root>'}..{to_ref or 'HEAD'}"
+        else:
+            ref_desc = "<full history>"
+
+        print(f"Range: {ref_desc}")
+        print()
+        print(changelog_text)
+        print()

pkgmgr/cli_core/dispatch.py

@@ -7,12 +7,15 @@ from pkgmgr.cli_core.context import CLIContext
 from pkgmgr.cli_core.proxy import maybe_handle_proxy
 from pkgmgr.get_selected_repos import get_selected_repos
 
-from pkgmgr.cli_core.commands.repos import handle_repos_command
-from pkgmgr.cli_core.commands.tools import handle_tools_command
-from pkgmgr.cli_core.commands.release import handle_release
-from pkgmgr.cli_core.commands.version import handle_version
-from pkgmgr.cli_core.commands.config import handle_config
-from pkgmgr.cli_core.commands.make import handle_make
+from pkgmgr.cli_core.commands import (
+    handle_repos_command,
+    handle_tools_command,
+    handle_release,
+    handle_version,
+    handle_config,
+    handle_make,
+    handle_changelog,
+)
 
 
 def dispatch_command(args, ctx: CLIContext) -> None:
@@ -43,6 +46,7 @@ def dispatch_command(args, ctx: CLIContext) -> None:
         "release",
         "version",
         "make",
+        "changelog",
     ]
 
     if args.command in commands_with_selection:
@@ -73,6 +77,8 @@ def dispatch_command(args, ctx: CLIContext) -> None:
         handle_release(args, ctx, selected)
     elif args.command == "version":
         handle_version(args, ctx, selected)
+    elif args.command == "changelog":
+        handle_changelog(args, ctx, selected)
     elif args.command == "config":
         handle_config(args, ctx)
     elif args.command == "make":

pkgmgr/cli_core/parser.py

@@ -306,6 +306,30 @@ def create_parser(description_text: str) -> argparse.ArgumentParser:
     )
     add_identifier_arguments(version_parser)
 
+
+
+    # ------------------------------------------------------------
+    # changelog
+    # ------------------------------------------------------------
+    changelog_parser = subparsers.add_parser(
+        "changelog",
+        help=(
+            "Show changelog derived from Git history. "
+            "By default, shows the changes between the last two SemVer tags."
+        ),
+    )
+    changelog_parser.add_argument(
+        "range",
+        nargs="?",
+        default="",
+        help=(
+            "Optional tag or range (e.g. v1.2.3 or v1.2.0..v1.2.3). "
+            "If omitted, the changelog between the last two SemVer "
+            "tags is shown."
+        ),
+    )
+    add_identifier_arguments(changelog_parser)
+
     # ------------------------------------------------------------
     # list
     # ------------------------------------------------------------