From 0bb092229a1c3716b4161a0f904e3b9982b8b804 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 19 Dec 2025 12:45:53 +0000
Subject: [PATCH 1/2] Initial plan


From cc92d499bfbcdbc38b75ad1d2eb2f7694dda18af Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 19 Dec 2025 12:51:39 +0000
Subject: [PATCH 2/2] fix(once): correct error handling to match standard once
 semantics

Co-authored-by: ASafaeirad <28571761+ASafaeirad@users.noreply.github.com>
---
 src/function/once.spec.ts | 19 ++++++++++++++++---
 src/function/once.ts      |  2 +-
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/function/once.spec.ts b/src/function/once.spec.ts
index d1593d4..ab54aea 100644
--- a/src/function/once.spec.ts
+++ b/src/function/once.spec.ts
@@ -93,14 +93,27 @@ describe('once', () => {
     expect(fn).toHaveBeenCalledOnce();
   });
 
-  it('should handle functions that throw errors', () => {
+  it('should not cache errors and retry on subsequent calls', () => {
+    let callCount = 0;
     const fn = vi.fn(() => {
-      throw new Error('Test error');
+      callCount++;
+      if (callCount < 2) {
+        throw new Error('Test error');
+      }
+      return 'success';
     });
     const onceFn = once(fn);
 
+    // First call throws
     expect(() => onceFn()).toThrow('Test error');
-    expect(() => onceFn()).not.toThrow(); // Returns cached undefined
     expect(fn).toHaveBeenCalledOnce();
+
+    // Second call succeeds and caches result
+    expect(onceFn()).toBe('success');
+    expect(fn).toHaveBeenCalledTimes(2);
+
+    // Third call returns cached result
+    expect(onceFn()).toBe('success');
+    expect(fn).toHaveBeenCalledTimes(2);
   });
 });
diff --git a/src/function/once.ts b/src/function/once.ts
index 378ff02..e9bf120 100644
--- a/src/function/once.ts
+++ b/src/function/once.ts
@@ -36,8 +36,8 @@ export function once<T extends (...args: any[]) => any>(fn: T): T {
     ...args: Parameters<T>
   ): ReturnType<T> {
     if (!called) {
-      called = true;
       result = fn.apply(this, args) as ReturnType<T>;
+      called = true;
       return result;
     }
     return result;