Function installRule

packages/cli/src/commands/setup.ts:229–271

Install a rule for an agent, handling both "file" (standalone) and "append" (AGENTS.md) types.

(
  agentName: SetupAgent,
  mode: SetupMode,
  scope: Scope
)

/** Install a rule for an agent, handling both "file" (standalone) and "append" (AGENTS.md) types. */
async function installRule(
  agentName: SetupAgent,
  mode: SetupMode,
  scope: Scope
): Promise<{ status: string; path: string }> {
  const agent = getAgent(agentName);
  const rule = agent.rule;
  const content = await getRuleContent(mode, agentName);

  if (rule.kind === "file") {
    const ruleDir =
      scope === "global" ? rule.dir("global") : join(process.cwd(), rule.dir("project"));
    const rulePath = join(ruleDir, rule.filename);
    await mkdir(dirname(rulePath), { recursive: true });
    await writeFile(rulePath, content, "utf-8");
    return { status: "installed", path: rulePath };
  }

  const filePath =
    scope === "global" ? rule.file("global") : join(process.cwd(), rule.file("project"));
  const escapedMarker = rule.sectionMarker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
  const section = `${rule.sectionMarker}\n${content}${rule.sectionMarker}`;

  let existing = "";
  try {
    existing = await readFile(filePath, "utf-8");
  } catch {
    // File doesn't exist yet
  }

  if (existing.includes(rule.sectionMarker)) {
    const regex = new RegExp(`${escapedMarker}\\n[\\s\\S]*?${escapedMarker}`);
    const updated = existing.replace(regex, section);
    await writeFile(filePath, updated, "utf-8");
    return { status: "updated", path: filePath };
  }

  const separator =
    existing.length > 0 && !existing.endsWith("\n") ? "\n\n" : existing.length > 0 ? "\n" : "";
  await mkdir(dirname(filePath), { recursive: true });
  await writeFile(filePath, existing + separator + section + "\n", "utf-8");
  return { status: "installed", path: filePath };
}

/**
 * For stdio transport, preserve an existing `@upstash/context7-mcp` invocation