Now this is the case, function a returns data asynchronously from Promise, and many other functions need to use this data. Now I have to process a().then() like this for every function that relies on this data

function a() {   
    return new Promise((resolve, reject) => {
    ....
    })
}

function getsub(id) {   
    return a()
    .then((data) => {
        return .....
    })
    .catch((err) => {...})
}


function tree(id) {   
    return a()
    .then((data) => {
        return .....
    })
    .catch((err) => {...})
}

There are some recursive cyclic dependencies. When the complexity increases, I feel like I am going crazy. Is there any other better way to write it?