feat(nestjs): migrate to NestJS

packages/server/src/utils/nested-array-to-flatten.ts

@@ -0,0 +1,33 @@
+import { omit, concat } from 'lodash';
+
+export const nestedArrayToFlatten = (
+  collection,
+  property = 'children',
+  parseItem = (a, level) => a,
+  level = 1,
+) => {
+  const parseObject = (obj) =>
+    parseItem(
+      {
+        ...omit(obj, [property]),
+      },
+      level,
+    );
+
+  return collection.reduce((items, currentValue, index) => {
+    let localItems = [...items];
+    const parsedItem = parseObject(currentValue);
+    localItems.push(parsedItem);
+
+    if (Array.isArray(currentValue[property])) {
+      const flattenArray = nestedArrayToFlatten(
+        currentValue[property],
+        property,
+        parseItem,
+        level + 1,
+      );
+      localItems = concat(localItems, flattenArray);
+    }
+    return localItems;
+  }, []);
+};