substitutionFruits.js

const fruits = [
    {name:'apple', price:20, total:0},
    {name:'banana', price:15, total:22},
    {name:'orange', price:13, total:23},
    {name:'melon', price:18, total:0}
]

const newFruits = [
    {name:'sausage', price:33, total:50},
    {name:'cornedbeef', price:25, total:38},
    {name:'beeftuna', price:15, total:13}
]

let substitution = (fruits, newFruits) => {
    let substitutedFruits = ''
    fruits.map( fruit => {
        newFruits.map( newFruit => {
            console.log(newFruit.name)
            if(fruit.total == 0 && !substitutedFruits.includes(newFruit.name)){
                Object.assign(fruit, newFruit)
                substitutedFruits += newFruit.name
            }
        })
    })
}

substitution(fruits, newFruits)
console.table(fruits)