fix: rabbit review

Author: turip

openmeter/billing/service/lineservice/service.go

@@ -57,7 +57,7 @@ func UpdateTotalsFromDetailedLines(line *billing.StandardLine) error {
 	}
 
 	// WARNING: Even if tempting to add discounts etc. here to the totals, we should always keep the logic as is.
-	// The usageBasedLine will never be syncorinzed directly to stripe or other apps, only the detailed lines.
+	// The usageBasedLine will never be synchronized directly to stripe or other apps, only the detailed lines.
 	//
 	// Given that the external systems will have their own logic for calculating the totals, we cannot expect
 	// any custom logic implemented here to be carried over to the external systems.

openmeter/billing/stdinvoiceline.go

@@ -297,6 +297,16 @@ func (i *StandardLine) SaveDBSnapshot() {
 
 func (i StandardLine) Validate() error {
 	var errs []error
+
+	// Fail fast cases (most of the validation logic uses these)
+	if i.UsageBased == nil {
+		return errors.New("usage based line is required")
+	}
+
+	if i.UsageBased.Price == nil {
+		return errors.New("usage based line price is required")
+	}
+
 	if err := i.StandardLineBase.Validate(); err != nil {
 		errs = append(errs, err)
 	}