BAAS-28597: Add counter for limiter wait calls

runtime.go

@@ -203,6 +203,7 @@ type Runtime struct {
 
 	limiter          *rate.Limiter
 	limiterTicksLeft int
+	limiterWaitCount uint64
 	ticks            uint64
 
 	tickMetricTrackingEnabled bool
@@ -213,6 +214,10 @@ func (self *Runtime) Ticks() uint64 {
 	return self.ticks
 }
 
+func (self *Runtime) LimiterWaitCount() uint64 {
+	return self.limiterWaitCount
+}
+
 // SetStackTraceLimit sets an upper limit to the number of stack frames that
 // goja will use when formatting an error's stack trace. By default, the limit
 // is 10. This is consistent with V8 and SpiderMonkey.

vm.go

@@ -617,6 +617,7 @@ func (vm *vm) run() {
 				ctx = context.Background()
 			}
 
+			vm.r.limiterWaitCount++
 			if waitErr := vm.r.limiter.WaitN(ctx, vm.r.limiterTicksLeft); waitErr != nil {
 				if vm.r.vm.ctx == nil {
 					panic(waitErr)