Function pruneAtBoundary

test/mcp-and-pruning.test.ts:71–83

(
    messages: Array<{ role: string; content: string | null }>,
    droppedGroupsCount: number,
  )

  // Inline copy of the logic (the real method is private to AgentLoop)
  function pruneAtBoundary(
    messages: Array<{ role: string; content: string | null }>,
    droppedGroupsCount: number,
  ): Array<{ role: string; content: string | null }> {
    const notice = `[CONTEXT_COMPACTED] ${droppedGroupsCount} earlier turn(s) omitted.\n\n---\n\n`;
    const flat = messages.slice();
    const first = flat[0];
    if (first?.role === 'user' && typeof first.content === 'string') {
      flat[0] = { ...first, content: notice + first.content };
      return flat;
    }
    return [{ role: 'user', content: notice }, ...flat];
  }

  it('merges notice into the first user message without creating duplicates', () => {
    const input = [