From 12fad19f7dd5390807a88286bd2b7e2b597bfc48 Mon Sep 17 00:00:00 2001
From: jizhuozhi <jizhuozhi.george@gmail.com>
Date: Fri, 19 Jul 2024 12:57:53 +0800
Subject: [PATCH] feat: recover panic and return as error

---
 api.go      | 14 ++++++++++++--
 api_test.go |  9 +++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/api.go b/api.go
index 3e74f2d..370d9f2 100644
--- a/api.go
+++ b/api.go
@@ -3,13 +3,25 @@ package future
 import (
 	"context"
 	"errors"
+	"fmt"
+	"runtime/debug"
 	"sync/atomic"
 	"time"
 )
 
+var ErrPanic = errors.New("async panic")
+var ErrTimeout = errors.New("future timeout")
+
 func Async[T any](f func() (T, error)) *Future[T] {
 	s := &state[T]{}
 	go func() {
+		defer func() {
+			if r := recover(); r != nil {
+				err := fmt.Errorf("%w, err=%s, stack=%s", ErrPanic, r, debug.Stack())
+				var zero T
+				s.set(zero, err)
+			}
+		}()
 		val, err := f()
 		s.set(val, err)
 	}()
@@ -72,8 +84,6 @@ func AllOf[T any](fs ...*Future[T]) *Future[struct{}] {
 	return &Future[struct{}]{state: s}
 }
 
-var ErrTimeout = errors.New("future timeout")
-
 func Timeout[T any](f *Future[T], d time.Duration) *Future[T] {
 	ch := make(chan struct{}, 1)
 	var val T
diff --git a/api_test.go b/api_test.go
index 0de9bfe..ab7ef69 100644
--- a/api_test.go
+++ b/api_test.go
@@ -22,6 +22,15 @@ func TestAsync(t *testing.T) {
 	assert.Equal(t, nil, err)
 }
 
+func TestAsyncPanic(t *testing.T) {
+	f := Async(func() (int, error) {
+		panic("panic")
+	})
+	val, err := f.Get()
+	assert.Equal(t, 0, val)
+	assert.ErrorIs(t, err, ErrPanic)
+}
+
 func TestLazy(t *testing.T) {
 	f := Lazy(func() (int, error) {
 		return 1, nil