package medtronic

import (
	"fmt"
)

const (
	bolus Command = 0x42

	maxBolus = 25000 // milliUnits
)

// Bolus delivers the given amount of insulin as a bolus.
// For safety, this command is not attempted more than once.
func (pump *Pump) Bolus(amount Insulin) {
	if amount < 0 {
		pump.SetError(fmt.Errorf("bolus amount (%d) is negative", amount))
	}
	if amount > maxBolus {
		pump.SetError(fmt.Errorf("bolus amount (%d) is too large", amount))
	}
	newer := pump.Family() >= 23
	d := milliUnitsPerStroke(newer)
	if amount%d != 0 {
		pump.SetError(fmt.Errorf("bolus (%d) is not a multiple of %d milliUnits per hour", amount, d))
		return
	}
	strokes := int(amount / d)
	n := pump.Retries()
	defer pump.SetRetries(n)
	pump.SetRetries(1)
	switch newer {
	case true:
		pump.Execute(bolus, marshalUint16(uint16(strokes))...)
	case false:
		pump.Execute(bolus, uint8(strokes))
	}
}

package medtronic

import (
	"fmt"
)

const (
	bolus Command = 0x42

	maxBolus = 25000 // milliUnits
)

// Bolus delivers the given amount of insulin as a bolus.
// For safety, this command is not attempted more than once.
func (pump *Pump) Bolus(amount Insulin) {
	if amount < 0 {
		pump.SetError(fmt.Errorf("bolus amount (%d) is negative", amount))
	}
	if amount > maxBolus {
		pump.SetError(fmt.Errorf("bolus amount (%d) is too large", amount))
	}
	newer := pump.Family() >= 23
	strokes := int(amount / milliUnitsPerStroke(newer))
	n := pump.Retries()
	defer pump.SetRetries(n)
	pump.SetRetries(1)
	switch newer {
	case true:
		pump.Execute(bolus, marshalUint16(uint16(strokes))...)
	case false:
		pump.Execute(bolus, uint8(strokes))
	}
}

--- 
+++ 
@@ -20,7 +20,12 @@
 		pump.SetError(fmt.Errorf("bolus amount (%d) is too large", amount))
 	}
 	newer := pump.Family() >= 23
-	strokes := int(amount / milliUnitsPerStroke(newer))
+	d := milliUnitsPerStroke(newer)
+	if amount%d != 0 {
+		pump.SetError(fmt.Errorf("bolus (%d) is not a multiple of %d milliUnits per hour", amount, d))
+		return
+	}
+	strokes := int(amount / d)
 	n := pump.Retries()
 	defer pump.SetRetries(n)
 	pump.SetRetries(1)
Enforce exact multiple of milliUnits/stroke in Bolus function
