fix(collection): reordered overloads of groupBy function

Reordered the overloads of the `groupBy` function for better type inference and usability. The change swaps the positions of the overloads to prioritize the more common use case where the `groupBy` function is used with an iterator function over the version that groups by a property path. This adjustment ensures that TypeScript correctly infers the types in scenarios where the distinction between the use cases is subtle, enhancing developer experience when working with the `groupBy` function.

packages/collection/groupBy.ts

@@ -13,10 +13,10 @@ type GroupedByIterator<T, R extends PropertyKey> =
       : { [K in keyof T as R]: Array<T[K]> } extends infer U ? { -readonly [K in keyof U]: U[K] } : never
 
 /**
- * Groups a collection by the value of a property at a given path.
+ * Groups a collection by the result of an iterator function.
  *
  * @param collection The collection to group.
- * @param path The path to the property to group by.
+ * @param iterator The iterator function to determine the group of each item.
  * @returns An object where the keys are the groups and the values are the items in each group.
  * @example
  * // Declare a collection.
@@ -28,18 +28,18 @@ type GroupedByIterator<T, R extends PropertyKey> =
  * ]
  *
  * // Group the collection by the value of the `group` property.
- * groupBy(collection, 'group')
+ * groupBy(collection, item => item.group)
  * // {
  * //   a: [{ id: 1, group: 'a' }, { id: 2, group: 'a' }],
  * //   b: [{ id: 3, group: 'b' }, { id: 4, group: 'b' }],
  * // }
  */
-export function groupBy<T, P extends IteratorPath<T>>(collection: T, path: MaybeLiteral<P>): GroupedByPath<T, P>
+export function groupBy<T, R extends PropertyKey>(collection: T, iterator: IteratorFunction<T, R>): GroupedByIterator<T, R>
 /**
- * Groups a collection by the result of an iterator function.
+ * Groups a collection by the value of a property at a given path.
  *
  * @param collection The collection to group.
- * @param iterator The iterator function to determine the group of each item.
+ * @param path The path to the property to group by.
  * @returns An object where the keys are the groups and the values are the items in each group.
  * @example
  * // Declare a collection.
@@ -51,14 +51,15 @@ export function groupBy<T, P extends IteratorPath<T>>(collection: T, path: Maybe
  * ]
  *
  * // Group the collection by the value of the `group` property.
- * groupBy(collection, item => item.group)
+ * groupBy(collection, 'group')
  * // {
  * //   a: [{ id: 1, group: 'a' }, { id: 2, group: 'a' }],
  * //   b: [{ id: 3, group: 'b' }, { id: 4, group: 'b' }],
  * // }
  */
-export function groupBy<T, R extends PropertyKey>(collection: T, iterator: IteratorFunction<T, R>): GroupedByIterator<T, R>
-export function groupBy(collection: object, iteratorOrPath: IteratorFunction<unknown, PropertyKey> | string) {
+export function groupBy<T, P extends IteratorPath<T>>(collection: T, path: MaybeLiteral<P>): GroupedByPath<T, P>
+export function groupBy(collection: object, iteratorOrPath: IteratorFunction<unknown, PropertyKey> | string): unknown
+export function groupBy(collection: object, iteratorOrPath: IteratorFunction<unknown, PropertyKey> | string): unknown {
 
   // --- If iterator is a string, cast as nested getter function.
   const iterator = typeof iteratorOrPath === 'function'