JS map and filter method chaining example

map-filter-method-chaining-example.js

const fakePokemons = [
    { name: 'Charizar', type: 'fire', isCaught: true},
    { name: 'Pokemon', type: 'electric', isCaught: true},
    { name: 'Ditto', type: 'normal', isCaught: false},
    { name: 'Eevee', type: 'normal', isCaught: true},
]

/**
 * Creates and returns a new object which has all the same 
 * properties as the poke object, but also has an `index` prop
 * and a `foo` prop
 * 
 * @param {*} poke  pokemon object
 * @param {*} index index int
 * @returns object
 */
const addStuffToPokeObject = (poke, index) => {
    return { 
        ...poke,  // destructures the obj into the object
        index: index, 
        foo: 'hello'
    }
};

const desired = 'normal'
const desiredPokemonsWithFoo = fakePokemons
    .filter(p => p.type === desired)
    .filter(p => p.isCaught === true)
    // .map(addStuffToPokeObject);
    .map((p, i) => ({ ...p, index: i, foo: 'hello'}))

console.log(desiredPokemonsWithFoo);