Issue with adding conditions to secret santa app - reactjs

Question

I'm working on creating secret santa app for my christmas party.
For now it works, but I need to add some conditions.
function App() {
var names = ["John", "Martha", "Adam", "Jane", "Michael"];
const shuffle = (arr: string[]) => {
for (let i = arr.length - 1; i > 0; i--) {
const j = Math.floor(Math.random() * (i + 1));
[arr[i], arr[j]] = [arr[j], arr[i]];
}
return arr;
};
const randomNames = shuffle(names);
const matches = randomNames.map((name, index) => {
return {
santa: name,
receiver: randomNames[index + 1] || randomNames[0],
};
});
return (
<div className="App">
<header className="App-header">
<img src={logo} className="App-logo" alt="logo" />
<p>Secret santa game</p>
<select>
<option>Select your name...</option>
{names.map((name) => (
<option> {name}</option>
))}
</select>
<div>
{matches.map((match) => {
return (
<div>
{match.receiver},{match.santa}
<br />
</div>
);
})}
</div>
</header>
</div>
);
}
export default App;
John and Martha are couple so they will buy themselves presents outside of the party anyway, so if one of them is receiver and another is santa, I want to generate results again so they'll be assigned to someone else.
I'm not sure how I can accomplish this.

Answer 1

You could define your relationships like this:
const couples = { John: "Martha" };
then have a function that verifies that your conditions are met:
const conditions_check = (santa: string, receiver: string) => {
if (couples[santa] === receiver) {
return false;
} else if (couples[receiver] === santa) {
return false;
}
return true;
};
and then finally you can check if your conditions are met while generating your matches and shuffle your pool of names again if needed:
let matches = randomNames.map((name, index) => {
let receiver = randomNames[(index + 1) % randomNames.length];
for (let i = 0; i < 25; i++) {
if (conditions_check(name, receiver)) {
break;
}
randomNames = shuffle(names);
}
return {
santa: name,
receiver: receiver
};
});
You can check out the whole implementation in this playground.