From e3e033bb359f1dba628eae38a57d2cf5c9072b9b Mon Sep 17 00:00:00 2001
From: keaipiao <71310981+keaipiao@users.noreply.github.com>
Date: Tue, 28 Jul 2026 11:46:12 -0700
Subject: [PATCH] fix(payment): preserve UTF-8 in EasyPay errors

---
 backend/internal/payment/provider/easypay.go        |  7 ++++++-
 .../payment/provider/easypay_refund_test.go         | 13 +++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/backend/internal/payment/provider/easypay.go b/backend/internal/payment/provider/easypay.go
index f1c17427a..c04f86479 100644
--- a/backend/internal/payment/provider/easypay.go
+++ b/backend/internal/payment/provider/easypay.go
@@ -15,6 +15,7 @@ import (
 	"strconv"
 	"strings"
 	"time"
+	"unicode/utf8"
 
 	"github.com/Wei-Shaw/sub2api/internal/payment"
 )
@@ -477,7 +478,11 @@ func summarizeEasyPayResponse(body []byte) string {
 		return "<empty>"
 	}
 	if len(summary) > maxEasypayErrorSummary {
-		return summary[:maxEasypayErrorSummary] + "..."
+		truncated := summary[:maxEasypayErrorSummary]
+		for len(truncated) > 0 && !utf8.ValidString(truncated) {
+			truncated = truncated[:len(truncated)-1]
+		}
+		return truncated + "..."
 	}
 	return summary
 }
diff --git a/backend/internal/payment/provider/easypay_refund_test.go b/backend/internal/payment/provider/easypay_refund_test.go
index 3b7632987..8d535b512 100644
--- a/backend/internal/payment/provider/easypay_refund_test.go
+++ b/backend/internal/payment/provider/easypay_refund_test.go
@@ -7,6 +7,7 @@ import (
 	"net/url"
 	"strings"
 	"testing"
+	"unicode/utf8"
 
 	"github.com/Wei-Shaw/sub2api/internal/payment"
 )
@@ -179,6 +180,18 @@ func TestEasyPayRefundResponseErrors(t *testing.T) {
 	}
 }
 
+func TestSummarizeEasyPayResponsePreservesUTF8(t *testing.T) {
+	t.Parallel()
+
+	summary := summarizeEasyPayResponse([]byte(strings.Repeat("错", 171)))
+	if !utf8.ValidString(summary) {
+		t.Fatalf("summarizeEasyPayResponse returned invalid UTF-8: %q", summary)
+	}
+	if !strings.HasSuffix(summary, "...") {
+		t.Fatalf("summarizeEasyPayResponse() = %q, want truncated suffix", summary)
+	}
+}
+
 func TestEasyPayCustomMethodsUseConfiguredUpstreamType(t *testing.T) {
 	t.Parallel()