Function mergeClaudeSettings

scripts/spec-init.ts:132–179

(existing: string)

 * at our gate, and only if no entry already references it.
 */
function mergeClaudeSettings(existing: string): string {
  let parsed: Record<string, unknown>;
  try {
    parsed = JSON.parse(existing);
  } catch {
    fail(
      `.claude/settings.json is not valid JSON; refusing to merge automatically. Fix or delete the file and re-run.`
    );
  }
  const hooks = (parsed.hooks ??= {}) as Record<string, unknown>;
  const pre = (hooks.PreToolUse ??= []) as unknown[];
  const alreadyWired = pre.some((entry) => {
    if (typeof entry !== "object" || entry === null) {
      return false;
    }
    const candidate = entry as { hooks?: unknown[] };

    return (
      Array.isArray(candidate.hooks) &&
      candidate.hooks.some((inner) => {
        if (typeof inner !== "object" || inner === null) {
          return false;
        }
        const command = (inner as { command?: unknown }).command;

        return (
          typeof command === "string" && command.includes("tools/spec-loop/hooks/gate")
        );
      })
    );
  });

  if (alreadyWired) {
    return existing;
  }

  pre.push({
    matcher: "Write|Edit|MultiEdit",
    hooks: [
      {
        type: "command",
        command: "bun tools/spec-loop/hooks/gate.ts"
      }
    ]
  });

  return JSON.stringify(parsed, null, 2) + "\n";
}

const PLAN: IPlan[] = [
  {