October 2025 Updates / Tests Coverage

[ok200paul]

Fixes #95.

Summary

Add comprehensive unit tests for VoucherService and fix a production bug discovered during testing.

Changes

Tests Added (20 tests, 327 assertions)

Complete test coverage for all public static methods in VoucherService:

• findUniqueShortCodeForVoucher() (4 tests)

  • Format validation (100 iterations)
  • Uniqueness verification
  • Collision avoidance with existing codes
  • Multiple unique code generation

• calculateVoucherAmountRedeemed() (4 tests)

  • Zero redemptions case
  • Single redemption sum
  • Multiple redemptions sum
  • Voucher-specific filtering

• calculateVoucherAmountRemaining() (5 tests)

  • Full value with no redemptions
  • Partial redemption calculations
  • Fully redeemed (zero) case
  • Over-redeemed (negative) edge case

• updateVoucherAmountRemaining() (3 tests)

  • Successful update flow
  • Exception on over-redemption
  • Database rollback on validation failure

• collateVoucherAggregates() (4 tests)

  • Complete field updates (remaining amount, redemption count, timestamps)
  • Short code removal when fully redeemed
  • Conditional field updates based on redemption state
  • Exception handling for over-redemption

Bug Fix

Fixed critical bug in VoucherService::collateVoucherAggregates() (line 93)

• last_redemption_at was being calculated without filtering by voucher_id
• This would have caused incorrect timestamps across all vouchers
• Changed: VoucherRedemption::where('voucher_id')->max('created_at')
• To: VoucherRedemption::where('voucher_id', $voucher->id)->max('created_at')

Documentation

• Added bidirectional @see annotations linking service methods to their tests
• Service methods reference all their test cases
• Test methods reference back to the implementation
• Enables easy IDE navigation between implementation and tests

Testing Notes

• Used withoutEvents() for over-redemption edge case tests to isolate calculation logic from event-driven validation
• Tests verify both happy paths and error conditions
• Database is refreshed between tests using RefreshDatabase trait

[dacook]

Great, indeed it's very comprehensive! Thanks for the detailed notes too.

I thought the @see comments seemed a bit over the top, until I remembered this was to aide navigation in IDE. That must be handy, but could get fiddly.

Glad to see this helped uncover a bug; it just goes to show how important tests are!