Validate array command - arrays

Question

As I put in the question I have these commands that work correctly but are not validated, which means that if I enter a name it simply makes the record not validating if this name already exists inside the array.
It sounds simple but I've tried to validate using array.find and then compare with the value before inserting but it does not work: for example in the command track I'm trying to validate if the name you are trying to insert already exists. In the command untrack if the name does not exist send a message, because that is another problem: if the name does not exist the command deletes the last inserted record.
If someone has the knowledge on how to make such validations, I would appreciate a little help.
const args = message.content.slice(prefix.length).trim().split(/ +/g);
const command = args.shift().toLowerCase();
if (command === "track") {
let [playerName, playerType] = args;
list.push({
name: playerName,
type: playerType
}) var logger = fs.createWriteStream('./realmtrack-config.json')
logger.write(JSON.stringify(config)) message.reply(`Player being tracked!`);
}
if (command === "untrack") {
let [playerName, playerType] = args;
let entry_to_delete = list.find((e: any) => e.name === playerName);
list.splice(list.indexOf(entry_to_delete), 1);
var logger = fs.createWriteStream('./realmtrack-config.json');
logger.write(JSON.stringify(config));
message.reply(`${playerName} stopped being tracked!`);
}

Answer 1

You have an array of objects
let list = [
{ name: "Joe", type: "Cool" },
{ name: "Sally", type: "Cool"}
]
You could create the below function to check if "Sally" is the name of one of the objects.
function(obj) {
return obj.name === "Sally"
}
We can make this shorter with ES6 arrow functions
obj => obj.name === "Sally"
Next, we can scour list for an argument which will return true when passed to that function.
list.some(obj => obj.name === "Sally")
.some will return false only if all of the elements in an array will return false when passed to the callback function. Otherwise, it returns true.
We can add the below line near the start of your message handler, then.
const isBeingTracked = list.some(obj => obj.name === args[0])
For the track command, you could add if(!isBeingTracked) { /* ... */ } (the ! means "not"). For the untrack command, you could add if(isBeingTracked) { /* ... */ }. /* ... */ is what you would replace for actual code.