## Problem
`DashboardAnalyticsTest > real estate balance evolution appends
projected mortgage balance from linked loan` fails on certain calendar
dates (e.g. when run on 2026-04-30) with:
```
Failed asserting that 17324874 is less than 17324874.
```
## Root cause
Carbon's `addMonths()` defaults to overflow mode, so adding months to a
day that doesn't exist in the target month rolls forward into the next
month:
- `2026-04-30 + 10 months` → `2027-02-30` → overflow → `2027-03-02`
- `2026-04-30 + 11 months` → `2027-03-30`
Both end up in the same `Y-m` (`2027-03`). The dashboard
balance-evolution endpoint and
`LoanAmortizationService::projectFromBalance` use `addMonths` to build
month-keyed projections and to label projected chart points. When two
iterations collapse onto the same `Y-m`:
1. `generateProjection` overwrites the earlier balance with the later
one.
2. The controller emits two consecutive projected points labeled with
that month and assigns the same `mortgage_balance` to both, breaking the
strictly-decreasing assertion.
## Fix
Switch every `addMonths()` call in the projection paths to
`addMonthsNoOverflow()` so each iteration lands on a distinct month.
- `app/Services/LoanAmortizationService.php` — `projectFromBalance`,
`projectFromOriginal`
- `app/Http/Controllers/Api/DashboardAnalyticsController.php` — real
estate projected loop
## Verification
```
php artisan test --compact tests/Feature/DashboardAnalyticsTest.php
Tests: 34 passed (220 assertions)
```
Previously failing on 2026-04-30, now green.
8f42496a5f