Вы можете переместить его в Объекты для обработки.
const getRollProps = (roll1) => {
const caseList = {
"21": {
"rain": 1.25
},
"22": {
"rain": 1.5,
"solid": "light"
},
"23": {
"rain": 1.75,
"solid": "light"
},
"24": {
"rain": 2,
"solid": "light"
},
"25": {
"rain": 2.25,
"solid": "medium"
},
"26": {
"rain": 2.5,
"solid": "medium",
"hook": 1
},
"27": {
"rain": 2.75,
"solid": "medium",
"hook": 5
},
"28": {
"rain": 3,
"solid": "heavy",
"hook": 10
},
"29": {
"rain": 3.25,
"solid": "heavy",
"hook": 15
},
"30": {
"rain": 3.5,
"solid": "heavy",
"hook": 20
}
};
const {rain, solid, hook} = (caseList[roll1] || {});
return [rain, solid, hook];
}
getRollProps(22);