Fix serialization for slices of OrderedMap/IterableOrderedMap (#1365) (#1418)

Author: earwin

lib/column/array.go

@@ -192,22 +192,17 @@ func appendNullableRowPlain[T any](col *Array, arr []*T) error {
 func (col *Array) append(elem reflect.Value, level int) error {
 	if level < col.depth {
 		switch elem.Kind() {
+		// allows to traverse pointers to slices and slices cast to `any`
+		case reflect.Interface, reflect.Ptr:
+			if !elem.IsNil() {
+				return col.append(elem.Elem(), level)
+			}
 		// reflect.Value.Len() & reflect.Value.Index() is called in `append` method which is only valid for
 		// Slice, Array and String that make sense here.
 		case reflect.Slice, reflect.Array, reflect.String:
 			col.appendOffset(level, uint64(elem.Len()))
 			for i := 0; i < elem.Len(); i++ {
-				el := elem.Index(i)
-
-				if el.Kind() == reflect.Interface && !el.IsNil() {
-					el = el.Elem()
-				}
-
-				if el.Kind() == reflect.Ptr && !el.IsNil() {
-					el = el.Elem()
-				}
-
-				if err := col.append(el, level+1); err != nil {
+				if err := col.append(elem.Index(i), level+1); err != nil {
 					return err
 				}
 			}

tests/issues/1365_test.go

@@ -0,0 +1,61 @@
+package issues
+
+import (
+	"context"
+	"github.com/ClickHouse/clickhouse-go/v2/lib/column"
+	"github.com/ClickHouse/clickhouse-go/v2/tests"
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+type T1365OrderedMap int
+
+func (t *T1365OrderedMap) Put(k any, v any) {
+	if k == "K" && v == "V" {
+		*t = 0xDEDEDEAD
+	}
+}
+func (t *T1365OrderedMap) Iterator() column.MapIterator { return t }
+func (t *T1365OrderedMap) Next() bool                   { *t++; return *t == 1 }
+func (t *T1365OrderedMap) Key() any                     { return "K" }
+func (t *T1365OrderedMap) Value() any                   { return "V" }
+
+func TestIssue1365(t *testing.T) {
+	ctx := context.Background()
+
+	conn, err := tests.GetConnection("issues", nil, nil, nil)
+	require.NoError(t, err)
+	defer conn.Close()
+
+	const ddl = `
+		CREATE TABLE test_1365 (
+				Col1 Array(Map(String,String))
+		) Engine MergeTree() ORDER BY tuple()
+		`
+	err = conn.Exec(ctx, ddl)
+	require.NoError(t, err)
+	defer conn.Exec(ctx, "DROP TABLE test_1365")
+
+	batch, err := conn.PrepareBatch(ctx, "INSERT INTO test_1365")
+	require.NoError(t, err)
+
+	var writeMaps []column.IterableOrderedMap
+	writeMaps = append(writeMaps, new(T1365OrderedMap))
+	writeMaps = append(writeMaps, new(T1365OrderedMap))
+
+	err = batch.Append(writeMaps)
+	require.NoError(t, err)
+
+	err = batch.Send()
+	require.NoError(t, err)
+
+	rows, err := conn.Query(ctx, "SELECT * FROM test_1365")
+	require.NoError(t, err)
+
+	require.True(t, rows.Next())
+
+	//var readMaps []*T1365OrderedMap
+	//
+	//err = rows.Scan(&readMaps)
+	//require.NoError(t, err)
+}