fixup! feat(@angular-ru/common): item functions type

Author: Markiewic

packages/common/docs/typings.md

@@ -213,7 +213,7 @@ type SomeLines = InfiniteTuple<string, 0>; // string[]
 
 ```ts
 type Number = LastOfTuple<[number]>; // number
-type NumberCouple = LastOfTuple<string[]>; // string
+type NumberCouple = LastOfTuple<string[]>; // string | undefined
 type NumberCouple = LastOfTuple<[string, boolean]>; // boolean
 type NumberCouple = LastOfTuple<[string, ...number[]]>; // string | number
 type NumberCouple = LastOfTuple<[]>; // undefined

packages/common/typings/src/last-of-tuple.ts

@@ -1,5 +1,7 @@
 export type LastOfTuple<ArrayType> = ArrayType extends unknown[]
     ? ArrayType extends []
         ? undefined
-        : ArrayType[ArrayType extends [unknown, ...infer Rest] ? Rest['length'] : number]
+        : ArrayType extends [unknown, ...unknown[]]
+        ? ArrayType[ArrayType extends [unknown, ...infer Rest] ? Rest['length'] : number]
+        : ArrayType[number] | undefined
     : undefined;