converting object of arrays to an array of objects in a desired format

Question

const getSelectedItemsIds = selectedItemsList => {
 let keys = Object.keys(selectedItemsList);
 let selectedItems = [];
 keys.map(k => {
 selectedItemsList[k].map(id => {
 if (k.includes("projectIds")) {
 return selectedItems.push({ type: "PROJECT", id });
 } else if (k.includes("subjectGroupIds")) {
 return selectedItems.push({
 type: "SUBJECT_GROUP",
 id
 });
 } else if (k.includes("subjectIds")) {
 return selectedItems.push({ type: "SUBJECT", id });
 }
 });
 });
 return selectedItems;
}

I have written my custom logic to get the desired result, if anyone can validate and tell me if there's a better way to do it. I'm adding input and expected out below:

I/P: 
{
 projectIds: [2]
 subjectGroupIds: [] // incase multiple subjects are grouped togehter
 subjectIds: [4]
}
Expected format:
[{"type":"PROJECT","id":2},{"type":"SUBJECT","id":4}]

Thanks in advance!

Answer 1

Your code is not bad. You use functional style to loop through the data, which is good. But inside the loop you do not have to check with if-elseif-elseif, as this is not solid when it comes to many many cases. Maybe it would be better to use a map object to guide the process of matching data.

getSelectedItemsIds = selectedItemsList => {
 const keyNamesMap = {
 projectIds: "PROJECT",
 subjectGroupIds: "SUBJECT_GROUP", 
 subjectIds: "SUBJECT"
 };
 let selectedItems = [];
 Object.keys(keyNamesMap).map( k => {
 selectedItemsList[k].map ( id => {
 selectedItems.push (
 {
 type: keyNamesMap[k],
 id: id
 }
 );
 }); 
 });
 return selectedItems;
}

This way it is more clear and more easy to add another type.