From ecd67dc56330f6787be56b717ba200fe3ef23ec5 Mon Sep 17 00:00:00 2001
From: kirillgroshkov <kirill.groshkov@naturalcycles.com>
Date: Tue, 5 Mar 2024 19:31:53 +0100
Subject: [PATCH] feat: _minBy/_maxBy now supports string comparisons

Previously only number comparisons were available
---
 src/array/array.util.test.ts |  4 ++++
 src/array/array.util.ts      | 12 ++++++------
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/array/array.util.test.ts b/src/array/array.util.test.ts
index 3b0e64ab..59cd7850 100644
--- a/src/array/array.util.test.ts
+++ b/src/array/array.util.test.ts
@@ -387,6 +387,10 @@ test('_maxBy, _minBy', () => {
   )
   expect(_minByOrUndefined([{ age: 18 }, { age: 30 }], u => u.age)).toEqual({ age: 18 })
   expect(_minBy([{ age: 18 }, { age: 30 }], u => u.age)).toEqual({ age: 18 })
+
+  expect(_minBy([{ date: '2023-06-22' }, { date: '2023-06-21' }], u => u.date)).toEqual({
+    date: '2023-06-21',
+  })
 })
 
 test('_zip', () => {
diff --git a/src/array/array.util.ts b/src/array/array.util.ts
index 3cc34bec..1fe4b421 100644
--- a/src/array/array.util.ts
+++ b/src/array/array.util.ts
@@ -395,13 +395,13 @@ export function _max<T>(array: T[]): NonNullable<T> {
   return a.reduce((max, item) => (max >= item ? max : item))
 }
 
-export function _maxBy<T>(array: T[], mapper: Mapper<T, number | undefined>): T {
+export function _maxBy<T>(array: T[], mapper: Mapper<T, number | string | undefined>): T {
   const max = _maxByOrUndefined(array, mapper)
   if (max === undefined) throw new Error(`_maxBy returned undefined`)
   return max
 }
 
-export function _minBy<T>(array: T[], mapper: Mapper<T, number | undefined>): T {
+export function _minBy<T>(array: T[], mapper: Mapper<T, number | string | undefined>): T {
   const min = _minByOrUndefined(array, mapper)
   if (min === undefined) throw new Error(`_minBy returned undefined`)
   return min
@@ -411,11 +411,11 @@ export function _minBy<T>(array: T[], mapper: Mapper<T, number | undefined>): T
 
 export function _maxByOrUndefined<T>(
   array: T[],
-  mapper: Mapper<T, number | undefined>,
+  mapper: Mapper<T, number | string | undefined>,
 ): T | undefined {
   if (!array.length) return
   let maxItem: T | undefined
-  let max: number | undefined
+  let max: number | string | undefined
   array.forEach((item, i) => {
     const v = mapper(item, i)
     if (v !== undefined && (max === undefined || v > max)) {
@@ -429,11 +429,11 @@ export function _maxByOrUndefined<T>(
 
 export function _minByOrUndefined<T>(
   array: T[],
-  mapper: Mapper<T, number | undefined>,
+  mapper: Mapper<T, number | string | undefined>,
 ): T | undefined {
   if (!array.length) return
   let minItem: T | undefined
-  let min: number | undefined
+  let min: number | string | undefined
   array.forEach((item, i) => {
     const v = mapper(item, i)
     if (v !== undefined && (min === undefined || v < min)) {