What’s a single word that means Contagious Happiness [closed]

I am searching for a single word that means contagious happiness or infectious happiness.

Not exactly a contagious happiness, but if you derive happiness from someone's else happiness, then it is called confelicitous happiness. In simple words, if you see someone happy, you feel their happiness. Thus, it makes you happy.

Confelicitous is an adjective, the noun form is

1) YourDictionary: https://www.yourdictionary.com/confelicity

2) Wikitionary: https://www.yourdictionary.com/confelicity

3) Definition.net: https://www.definitions.net/definition/confelicity

Confelicity (uncountable noun)

(rare) Pleasure in another's happiness.