fix: panic in ordered_map Key() (#721)

* fix: panic in ordered_map Key()

* test: improve ordered map

libs/ds/ordered_map.go

@@ -68,12 +68,15 @@ func (m *OrderedMap[T, V]) Delete(key T) {
 	if !ok {
 		return
 	}
-	i++
-	for ; i < len(m.values); i++ {
-		m.values[i-1] = m.values[i]
-	}
 	delete(m.keys, key)
+
+	m.values = append(m.values[:i], m.values[i+1:]...)
 	m.len--
+	for k, v := range m.keys {
+		if v > i {
+			m.keys[k] = v - 1
+		}
+	}
 }
 
 // Values returns all values in the map

libs/ds/ordered_map_test.go

@@ -5,6 +5,7 @@ import (
 	"sync"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -59,3 +60,25 @@ func TestOrderedMapMultithread(t *testing.T) {
 
 	wg.Wait()
 }
+
+func TestOrderedMapDelete(t *testing.T) {
+	m := NewOrderedMap[int, int]()
+	m.Put(1, 1)
+	m.Put(2, 2)
+	m.Put(3, 3)
+	m.Delete(2)
+	keys := m.Keys()
+	if len(keys) != 2 {
+		t.Errorf("Expected 2 keys, got %d", len(keys))
+	}
+	if keys[0] != 1 && keys[1] != 3 {
+		t.Errorf("Expected keys [1, 3], got %v", keys)
+	}
+	v1, ok := m.Get(1)
+	assert.Equal(t, v1, 1)
+	assert.True(t, ok)
+
+	v3, ok := m.Get(3)
+	assert.Equal(t, v3, 3)
+	assert.True(t, ok)
+}