Merge pull request #96 from alitto/fix/AD/stack-traces

fix(panics): wrap panic errors correctly and include stack trace

default_test.go

@@ -2,6 +2,7 @@ package pond
 
 import (
 	"errors"
+	"strings"
 	"sync/atomic"
 	"testing"
 
@@ -41,7 +42,7 @@ func TestSubmitWithPanic(t *testing.T) {
 	err := task.Wait()
 
 	assert.True(t, errors.Is(err, ErrPanic))
-	assert.Equal(t, "task panicked: dummy panic", err.Error())
+	assert.True(t, strings.HasPrefix(err.Error(), "task panicked: dummy panic"))
 }
 
 func TestNewGroup(t *testing.T) {

pool_test.go

@@ -3,6 +3,7 @@ package pond
 import (
 	"context"
 	"errors"
+	"regexp"
 	"sync/atomic"
 	"testing"
 	"time"
@@ -48,14 +49,29 @@ func TestPoolSubmitWithPanic(t *testing.T) {
 
 	pool := NewPool(100)
 
+	sampleErr := errors.New("sample error")
+
 	task := pool.Submit(func() {
-		panic("dummy panic")
+		panic(sampleErr)
 	})
 
 	err := task.Wait()
 
+	// The returned error should be a wrapped error containing the panic error.
 	assert.True(t, errors.Is(err, ErrPanic))
-	assert.Equal(t, "task panicked: dummy panic", err.Error())
+	assert.True(t, errors.Is(err, sampleErr))
+
+	wrappedErrors := (err).(interface {
+		Unwrap() []error
+	}).Unwrap()
+
+	assert.Equal(t, 2, len(wrappedErrors))
+	assert.Equal(t, ErrPanic, wrappedErrors[0])
+	assert.Equal(t, sampleErr, wrappedErrors[1])
+
+	matches, err := regexp.MatchString(`task panicked: sample error, goroutine \d+ \[running\]:\n\s*runtime/debug\.Stack\(\)`, err.Error())
+	assert.True(t, matches)
+	assert.Equal(t, nil, err)
 }
 
 func TestPoolSubmitWithErr(t *testing.T) {

result_test.go

@@ -2,6 +2,7 @@ package pond
 
 import (
 	"errors"
+	"strings"
 	"sync/atomic"
 	"testing"
 
@@ -34,7 +35,7 @@ func TestResultPoolSubmitTaskWithPanic(t *testing.T) {
 	output, err := task.Wait()
 
 	assert.True(t, errors.Is(err, ErrPanic))
-	assert.Equal(t, "task panicked: dummy panic", err.Error())
+	assert.True(t, strings.HasPrefix(err.Error(), "task panicked: dummy panic"))
 	assert.Equal(t, 0, output)
 }
 

task.go

@@ -3,6 +3,7 @@ package pond
 import (
 	"errors"
 	"fmt"
+	"runtime/debug"
 	"sync"
 )
 
@@ -62,7 +63,11 @@ func wrapTask[R any, C func(error) | func(R, error)](task any, callback C) func(
 func invokeTask[R any](task any) (output R, err error) {
 	defer func() {
 		if p := recover(); p != nil {
-			err = fmt.Errorf("%w: %v", ErrPanic, p)
+			if e, ok := p.(error); ok {
+				err = fmt.Errorf("%w: %w, %s", ErrPanic, e, debug.Stack())
+			} else {
+				err = fmt.Errorf("%w: %v, %s", ErrPanic, p, debug.Stack())
+			}
 			return
 		}
 	}()