original code for improve-stack-post

index.js

function getName () {
    return new Promise((resolve)=>{
        resolve({status:500});
    }); // emulate http call
}

function getFullName (info) {
    return new Promise((resolve) => {
        resolve(info.firstName + ' ' + info.lastName)
    })
}

function countLetter(fullName, letter){
    return new Promise((resolve)=>{
        resolve(fullName.split(letter).length-1);
    })
}
function countLetters (fullName) {
    const result = {};
    return Promise.all('abcdefghijklmnopqrstuvwxyz'.split('').map((char)=>{
        countLetter(fullName, char).then((count)=>{
            result[char] = count;
        })
    })).then(()=>result);
}

function analyzeName () {
    let result = {};
    return getName().then(({data}) => {
        result.name = data;
        getFullName(data);
    }).then((fullName) => {
        result.fullName = fullName;
        return countLetters(fullName)
    }).then((count)=>{
        result.count = count;
    }).then(()=>{
        return result
    })
}

analyzeName().then((result) => {
    console.log(result);
});