How to check if else code (log ?)

1

I have this code
- name: Temp Sensors
entities:
- sensor.dressingkleur_template
text_template: ‘${entity.state ? Math.round(entity.state) + “°C” : “undefined”}’
class_template: ’
var temp = parseFloat(entity.state.replace(“°”, “”));
if (temp < 15)
return “temp-in-very-low”;
else if (temp < 25)
return “temp-in-low”;
else if (temp < 30)
return “temp-in-good”;
else if (temp < 35)
return “temp-in-high”;
else
return “temp-in-too-high”;
’

How can I see what is returned ? Because I get no errors, but my colour that has to change by css code doesnt change …