refactor(core/errorx): use errors.Join simplify error handle

Replace the manual error string concatenation in errorArray.Error() with errors.Join() from the errors package to streamline error formatting.

(cherry picked from commit b68659d)

core/errorx/batcherror.go

@@ -1,7 +1,7 @@
 package errorx
 
 import (
-	"bytes"
+	"errors"
 	"sync"
 )
 
@@ -52,14 +52,10 @@ func (be *BatchError) NotNil() bool {
 
 // Error returns a string that represents inside errors.
 func (ea errorArray) Error() string {
-	var buf bytes.Buffer
-
-	for i := range ea {
-		if i > 0 {
-			buf.WriteByte('\n')
-		}
-		buf.WriteString(ea[i].Error())
-	}
+	return errors.Join(ea...).Error()
+}
 
-	return buf.String()
+// Unwrap combine the errors in the errorArray into a single error return
+func (ea errorArray) Unwrap() error {
+	return errors.Join(ea...)
 }

core/errorx/batcherror_test.go

@@ -66,3 +66,32 @@ func TestBatchErrorConcurrentAdd(t *testing.T) {
 	assert.Equal(t, count, len(batch.errs))
 	assert.True(t, batch.NotNil())
 }
+
+func TestBatchError_Unwrap(t *testing.T) {
+	t.Run("nil", func(t *testing.T) {
+		var be BatchError
+		assert.Nil(t, be.Err())
+		assert.True(t, errors.Is(be.Err(), nil))
+	})
+
+	t.Run("one error", func(t *testing.T) {
+		var errFoo = errors.New("foo")
+		var errBar = errors.New("bar")
+		var be BatchError
+		be.Add(errFoo)
+		assert.True(t, errors.Is(be.Err(), errFoo))
+		assert.False(t, errors.Is(be.Err(), errBar))
+	})
+
+	t.Run("two errors", func(t *testing.T) {
+		var errFoo = errors.New("foo")
+		var errBar = errors.New("bar")
+		var errBaz = errors.New("baz")
+		var be BatchError
+		be.Add(errFoo)
+		be.Add(errBar)
+		assert.True(t, errors.Is(be.Err(), errFoo))
+		assert.True(t, errors.Is(be.Err(), errBar))
+		assert.False(t, errors.Is(be.Err(), errBaz))
+	})
+}