Ship Vertical Slice

Source: custom-skills/ship-vertical-slice/SKILL.md

Ship one thin end-to-end path before polishing edge cases or refactoring.

Table of Contents

Ship vertical slice

Ship one thin end-to-end path before polishing edge cases or refactoring.

Slice template

Input (CLI args)
  → validate / parse
  → carrier adapter (fixture or client)
  → domain types (TrackingEvent[])
  → formatTimeline() + next-action copy
  → stdout + exit code

Workflow

  1. Write the test first — one happy-path integration test from argv to expected stdout.
  2. Implement the narrowest path — skip flags you do not need yet.
  3. Add one failure test — bad id, unknown carrier, or adapter throw.
  4. Document user-facing changes — README flag table + example command.
  5. Run the session checklist from CLAUDE.md:
    • npm test before and after
    • Re-run only the tests you touched if iterating

Scope guardrails

  • Do not add a database, web UI, or label printing in the same slice.
  • Do not refactor unrelated carriers — leave drive-by cleanups for a separate PR.
  • Keep diffs commit-sized; if the slice spans more than ~3 files, split it.

Exit codes (do not change casually)

Code Meaning
0 Success
1 Usage / validation (bad args, unknown flag)
2 Carrier or runtime failure

Done when

  • Happy + one failure path covered
  • README updated for anything users type differently
  • Verbose output still PII-safe (run /review-pii-redaction if you added logging)