feat: overages should be rouned down to nearest integer (#10826)

frontend/src/component/admin/billing/BillingInvoices/BillingInvoice/BillingInvoiceUsageRow/BillingInvoiceUsageRow.tsx

@@ -14,7 +14,7 @@ const hasValidUsageData = (consumption?: number, limit?: number): boolean => {
 
 const calculateOverage = (consumption?: number, limit?: number): number => {
     return hasValidUsageData(consumption, limit)
-        ? Math.max(0, consumption! - limit!)
+        ? Math.floor(Math.max(0, consumption! - limit!))
         : 0;
 };
 

frontend/src/component/admin/billing/BillingInvoices/BillingInvoice/calculateEstimateTotals.test.ts

@@ -274,5 +274,27 @@ describe('calculateEstimateTotals', () => {
                 totalAmount: 110,
             });
         });
+
+        it('rounds down overages to integers', () => {
+            const usageLines = [
+                createUsageLine(150.7, 100, 2),
+                createUsageLine(200.3, 150, 1.5),
+            ];
+            const result = calculateEstimateTotals(
+                'estimate',
+                0,
+                0,
+                0,
+                10,
+                [],
+                usageLines,
+            );
+
+            expect(result).toEqual({
+                subtotal: 175,
+                taxAmount: 17.5,
+                totalAmount: 192.5,
+            });
+        });
     });
 });

frontend/src/component/admin/billing/BillingInvoices/BillingInvoice/calculateEstimateTotals.ts

@@ -25,7 +25,7 @@ export const calculateEstimateTotals = (
     const usageLinesTotal = usageLines.reduce((sum, line) => {
         const overage =
             line.consumption && line.limit
-                ? Math.max(0, line.consumption - line.limit)
+                ? Math.floor(Math.max(0, line.consumption - line.limit))
                 : 0;
         return sum + overage * (line.unitPrice || 0);
     }, 0);