test: improve utils coverage (#4230)

* test: improve utils coverage

* refactor: review - rename isDefined to isNonNullable, update tests and return statement

packages/twenty-front/src/utils/array/mapArrayToObject.ts

@@ -1,4 +1,27 @@
-export const mapArrayToObject = <ArrayItem>(
+/**
+ * Transforms an array of items into an object where the keys are computed from each item.
+ *
+ * @param array - The array to transform.
+ * @param computeItemKey - A function that computes a key from an item.
+ *
+ * @returns An object where the keys are computed from the items in the array.
+ *
+ * @example
+ * mapArrayToObject(
+ *   [{ id: '1', type: 'fruit' }, { id: '2', type: 'vegetable' }, { id: '3', type: 'fruit' }],
+ *   ({ id }) => id,
+ * )
+ * ⬇️
+ * {
+ *  '1': { id: '1', type: 'fruit' },
+ *  '2': { id: '2', type: 'vegetable' },
+ *  '3': { id: '3', type: 'fruit' },
+ * }
+ */
+export const mapArrayToObject = <ArrayItem, Key extends string>(
   array: ArrayItem[],
-  computeItemKey: (item: ArrayItem) => string,
-) => Object.fromEntries(array.map((item) => [computeItemKey(item), item]));
+  computeItemKey: (item: ArrayItem) => Key,
+) =>
+  Object.fromEntries(
+    array.map((item) => [computeItemKey(item), item]),
+  ) as Record<Key, ArrayItem>;