clickhouse-go-655 Establish batch semantics (#853)

tests/issues/655_test.go

@@ -0,0 +1,40 @@
+package issues
+
+import (
+	"context"
+	"github.com/ClickHouse/clickhouse-go/v2"
+	clickhouse_tests "github.com/ClickHouse/clickhouse-go/v2/tests"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+// Test655 confirms an agreed semantic on failing batch append results with entire batch cancellation.
+func Test655(t *testing.T) {
+	var (
+		conn, err = clickhouse_tests.GetConnection("issues", clickhouse.Settings{
+			"max_execution_time": 60,
+		}, nil, &clickhouse.Compression{
+			Method: clickhouse.CompressionLZ4,
+		})
+		ctx = context.Background()
+	)
+
+	require.NoError(t, err)
+	conn.Exec(ctx, "DROP TABLE test_enum")
+	const ddl = `CREATE TABLE test_enum (
+				Col1 Enum8 ('Click'=5, 'House'=25)
+			) Engine Memory`
+	require.NoError(t, conn.Exec(ctx, ddl))
+
+	defer func() {
+		conn.Exec(ctx, "DROP TABLE test_enum")
+	}()
+	batch, err := conn.PrepareBatch(ctx, "INSERT INTO test_enum")
+	require.NoError(t, err)
+	type request struct {
+		Col1 string
+	}
+	require.Error(t, batch.AppendStruct(&request{Col1: "house"}), "clickhouse [AppendRow]: (Col1 Enum8('Click' = 5, 'House' = 25)) unknown element \"house\"")
+	assert.ErrorContains(t, batch.Send(), "clickhouse: batch is invalid. check appended data is correct")
+}