From ba25d37d7a2f16d1497677558c4bcb1ad874ba36 Mon Sep 17 00:00:00 2001
From: xgfone <xgfone@126.com>
Date: Wed, 12 Jul 2023 17:11:11 +0800
Subject: [PATCH] fix the integer string check

---
 cast.go      | 15 +++++++++++++--
 cast_test.go |  4 ++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/cast.go b/cast.go
index 037f112..f244ef8 100644
--- a/cast.go
+++ b/cast.go
@@ -889,9 +889,20 @@ func tryReflectToTimeInLocation(src reflect.Value, loc *time.Location,
 }
 
 func isIntegerString(s string) bool {
-	for i, _len := 0, len(s); i < _len; i++ {
+	_len := len(s)
+	if _len == 0 {
+		return false
+	}
+
+	switch s[0] {
+	case '-', '+':
+		s = s[1:]
+		_len--
+	}
+
+	for i := 0; i < _len; i++ {
 		switch s[i] {
-		case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '-':
+		case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
 		default:
 			return false
 		}
diff --git a/cast_test.go b/cast_test.go
index b42d649..2572f9b 100644
--- a/cast_test.go
+++ b/cast_test.go
@@ -242,4 +242,8 @@ func TestIsIntegerString(t *testing.T) {
 	} else if v != -1000 {
 		t.Errorf("expect %d, but got %d", -1000, v)
 	}
+
+	if isIntegerString("2006-01-02") {
+		t.Error("2006-01-02: expect false, but got true")
+	}
 }