You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
22 lines
442 B
JavaScript
22 lines
442 B
JavaScript
3 years ago
|
"use strict";
|
||
|
|
||
|
// FIXME: Publish as separate non-modular-matrix package
|
||
|
|
||
|
module.exports = function createItemDeduplicator(getKey) {
|
||
|
let items = new Map();
|
||
|
|
||
|
return function deduplicateItem(item) {
|
||
|
let key = getKey(item);
|
||
|
|
||
|
if (key == null) {
|
||
|
// We cannot deduplicate an item that doesn't have a key
|
||
|
return item;
|
||
|
} else if (items.has(key)) {
|
||
|
return items.get(key);
|
||
|
} else {
|
||
|
items.set(key, item);
|
||
|
return item;
|
||
|
}
|
||
|
};
|
||
|
};
|