diff --git a/document/document_test.go b/document/document_test.go
index 28f1090..fc1594b 100644
--- a/document/document_test.go
+++ b/document/document_test.go
@@ -1,7 +1,9 @@
 package document
 
 import (
+	"fmt"
 	"os"
+	"sync"
 	"testing"
 )
 
@@ -56,4 +58,53 @@ func TestDocumentStore(t *testing.T) {
 	if err := ds.GetDocument(testID, &result); err == nil {
 		t.Errorf("Expected error after DeleteDocument")
 	}
-}
\ No newline at end of file
+}
+
+func TestErrorHandling(t *testing.T) {
+	// 测试无效文档（包含不支持的类型）
+	dir := "./testdb_error"
+	defer os.RemoveAll(dir)
+
+	ds, _ := NewDocumentStore(dir)
+	invalidDoc := struct {
+		F func()
+	}{}
+
+	if err := ds.StoreDocument("invalid", invalidDoc); err == nil {
+		t.Error("Expected error for invalid document")
+	}
+}
+
+func TestConcurrentAccess(t *testing.T) {
+	// 测试并发写入同一ID
+	dir := "./testdb_concurrent"
+	defer os.RemoveAll(dir)
+
+	numGoroutines := 10
+	var wg sync.WaitGroup
+	key := "concurrent_test"
+
+	ds, _ := NewDocumentStore(dir)
+	wg.Add(numGoroutines)
+
+	for i := 0; i < numGoroutines; i++ {
+		go func(i int) {
+			defer wg.Done()
+			testDoc := TestDoc{
+				ID:   key,
+				Name: fmt.Sprintf("Test%d", i),
+			}
+			err := ds.StoreDocument(key, testDoc)
+			if err != nil {
+				t.Errorf("StoreDocument failed: %v", err)
+			}
+		}(i)
+	}
+	wg.Wait()
+
+	// 验证最终值是否为最后一个写入
+	var result TestDoc
+	if err := ds.GetDocument(key, &result); err != nil {
+		t.Errorf("GetDocument failed: %v", err)
+	}
+}