Plan saved to docs/plans/2026-03-02-ping-command.md.

4 files to touch, 13 atomic steps.

Chosen approach: Standalone script pattern (same as sw-hello.sh) — rejected inline-in-router because it breaks the modular convention used by all 100+ commands.

• Task 1: Create scripts/sw-ping-test.sh with 6 test cases (output, exit 0, --help, -h, --version, invalid option)
• Task 2: Run test to confirm it fails (TDD red — script doesn't exist yet)
• Task 3: Create scripts/sw-ping.sh with echo "pong" main path
• Task 4: chmod +x scripts/sw-ping.sh
• Task 5: Run bash scripts/sw-ping-test.sh — confirm 6/6 pass
• Task 6: Commit sw-ping.sh and sw-ping-test.sh
• Task 7: Add ping) case to scripts/sw router after hello) block
• Task 8: Verify bash scripts/sw ping outputs pong
• Task 9: Commit router change
• Task 10: Insert sw-ping-test.sh into package.json test chain
• Task 11: Verify registration with node one-liner
• Task 12: Run bash scripts/sw-ping-test.sh — confirm still 6/6
• Task 13: Commit package.json change

• Router insertion position — must go BEFORE the *) catch-all, AFTER hello). Plan specifies exact location (line 607).
• set -euo pipefail + exit code capture in tests — use || local exit_code=$? pattern (same as hello test), not bare $?.
• VERSION — copy 3.2.4 from sw-hello.sh exactly.

• bash scripts/sw-ping.sh → prints pong, exits 0
• bash scripts/sw ping (via router) → prints pong, exits 0
• bash scripts/sw-ping-test.sh → PASS: 6 / FAIL: 0
• sw-ping-test.sh registered in package.json test chain