Method execute

src/tools/git/release-notes.ts:55–142

(args: Args, ctx: ToolContext)

  argsSchema = ReleaseNotesArgs;

  async execute(args: Args, ctx: ToolContext): Promise<ToolResult> {
    if (!await isGitRepo(ctx.cwd, ctx.signal)) {
      return { content: '[NOT_A_GIT_REPO] Current directory is not a git working tree.', isError: true };
    }

    const to = args.to ?? 'HEAD';
    const scope = args.scope ?? 'user';
    const format = args.format ?? 'markdown';
    const maxCommits = args.max_commits ?? 500;

    // Resolve `from`. If omitted, find latest tag reachable from `to`; else fall back to repo root.
    let from = args.from;
    let fromSource = 'user-provided';
    if (!from) {
      const r = await git(['describe', '--tags', '--abbrev=0', to], { cwd: ctx.cwd, signal: ctx.signal });
      if (r.exitCode === 0 && r.stdout.trim()) {
        from = r.stdout.trim();
        fromSource = `latest tag: ${from}`;
      } else {
        // No tag — use root commit
        try {
          const root = (await gitOrThrow(['rev-list', '--max-parents=0', to], { cwd: ctx.cwd, signal: ctx.signal })).trim().split('\n')[0];
          if (!root) {
            return { content: '[EMPTY_REPO] Could not find any commits.', isError: true };
          }
          from = root;
          fromSource = `repo root (no tags found)`;
        } catch (e: any) {
          return { content: `[ERROR] Could not resolve starting commit: ${e.message}`, isError: true };
        }
      }
    }

    // Build the range expression. `from..to` excludes `from` itself — desired behaviour
    // when `from` is a tag (we don't want to re-list its commits).
    const range = `${from}..${to}`;

    const commits = await readCommits(ctx.cwd, range, maxCommits, ctx.signal);
    if (commits.length === 0) {
      return {
        content: `[NO_CHANGES] No commits in range ${range} (${fromSource}).`,
        metadata: { range, fromSource, count: 0 },
      };
    }

    const buckets = bucket(commits);
    const heading = args.heading ?? deriveHeading(to);
    const md = formatMarkdown(buckets, { scope, heading, range });

    let written: string[] = [];
    if (args.write_to_changelog) {
      const changelogPath = path.join(ctx.cwd, 'CHANGELOG.md');
      const existing = await readIfExists(changelogPath);
      const header = existing.startsWith('# ') ? '' : '# Changelog\n\n';
      const next = header + md + (existing ? '\n' + existing.replace(/^# Changelog\s*\n+/, '') : '');
      await fs.writeFile(changelogPath, next, 'utf-8');
      written.push('CHANGELOG.md');
      ctx.emit({ type: 'diff', path: changelogPath, before: existing || null, after: next });