From c96213137ef8bd48ba3b06c609fca6d005fe8c6b Mon Sep 17 00:00:00 2001
From: robonen <robonenandrew@gmail.com>
Date: Sat, 26 Oct 2024 06:37:27 +0700
Subject: [PATCH] refactor(packages/stdlib): stack return undefined on peek if
 it empty

---
 packages/stdlib/src/structs/stack/index.test.ts | 6 ++++--
 packages/stdlib/src/structs/stack/index.ts      | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/packages/stdlib/src/structs/stack/index.test.ts b/packages/stdlib/src/structs/stack/index.test.ts
index e67522a..7d3920a 100644
--- a/packages/stdlib/src/structs/stack/index.test.ts
+++ b/packages/stdlib/src/structs/stack/index.test.ts
@@ -79,9 +79,11 @@ describe('stack', () => {
       expect(stack.length).toBe(3);
     });
 
-    it('throw an error if the stack is empty', () => {
+    it('return undefined if the stack is empty', () => {
       const stack = new Stack<number>();
-      expect(() => stack.peek()).toThrow(new RangeError('Stack is empty'));
+      const topElement = stack.peek();
+
+      expect(topElement).toBeUndefined();
     });
   });
 
diff --git a/packages/stdlib/src/structs/stack/index.ts b/packages/stdlib/src/structs/stack/index.ts
index db48251..6a6d1af 100644
--- a/packages/stdlib/src/structs/stack/index.ts
+++ b/packages/stdlib/src/structs/stack/index.ts
@@ -96,7 +96,7 @@ export class Stack<T> implements Iterable<T>, AsyncIterable<T> {
      */
     public peek() {
         if (this.isEmpty)
-            throw new RangeError('Stack is empty');
+            return undefined;
         
         return last(this.stack);
     }